Center for Superconducting and Magnetic Materials

The Center for Superconducting and Magnetic Materials (CSMM), founded at OSU in 1995, has its strongest emphasis on superconducting materials, including their formation and structure as well as their magnetic and electrical properties. CSMM has research programs in various aspects of superconducting materials, including MgB2, Nb3Sn, and YBCO. Phase formation, reactions, diffusion, and microstructure are studied in MgB2 and Nb3Sn, as well as transport, magnetic, and flux pinning. Its activities embody a wide range of Materials Science as well as Engineering topics. Those presently under investigation include: high-pressure/high-temperature study of the Mg-B phase diagram, phase evolution and A15 Nb3Sn formation within the ternary Nb-Sn-Cu diagram, microstructure and critical current density optimization in MgB2 and Nb3Sn superconducting wires, formation and properties (microstructural, electrical, and magnetic) of films formed by pulsed laser deposition, electropolishing characteristics of niobium for superconducting RF (SRF) cavities, and bulge testing of niobium tube in support of a program for hydroforming SRF cavity strings.

E.W. Collings (Director), M.D. Sumption (Associate Director)

The Center for Superconducting and Magnetic Materials (CSMM) has its strongest emphasis on superconducting materials, including their formation and structure as well as their magnetic and electrical properties. CSMM has research programs in various aspects of superconducting materials, including MgB2, Nb3Sn, and YBCO. Phase formation, reactions, diffusion, and microstructure are studied in MgB2 and Nb3Sn, as well as transport, magnetic, and flux pinning. Its activities embody a wide range of Materials Science as well as Engineering topics. Those presently under investigation include: high-pressure/high-temperature study of the Mg-B phase diagram, phase evolution and A15 Nb3Sn formation within the ternary Nb-Sn-Cu diagram, microstructure and critical current density optimization in MgB2 and Nb3Sn superconducting wires, formation and properties (microstructural, electrical, and magnetic) of films formed by pulsed laser deposition, electropolishing characteristics of niobium for superconducting RF (SRF) cavities, and bulge testing of niobium tube in support of a program for hydroforming SRF cavity strings.

Relationship and Connection to Energy Related Topics: Superconducting AC power transmission lines have been pursued by the DOE over the last 10 years (YBCO is the material of interest here), but more recently the focus has moved to either large scale DC links, or to more localized systems, such as fault current limiters. Fault current limiters could be deployed to reduce faults within the US power grid, and also to reduce costs associated with substation upgrades. A push for offshore wind turbine generators has made superconducting based wind turbine generators of interest because of full cost of ownership issues (mostly the cost of the tower and the installation costs). Here YBCO and also MgB2 are strong contenders. Superconducting magnetic energy storage has recently been of interest to ARPA-E, with an emphasis on very high field structures, 30 MJ size. Tokomak fusion machines employ superconductors to contain the plasma. Presently Nb3Sn is used for this, but there is strong interest in MgB2 and YBCO. CSMM presently has programs in fault current limiters, SMES, and fusion conductors, and is actively pursuing programs in wind turbine generators.

Experimental facilities: Within CSMM itself, extensive cryogenic, electrical transport, and magnetic measurement facilities are in use. Part of the Center for Superconducting and Magnetic Materials is the Superconducting Technology Center (SuTC). This center has the aim of encouraging the development of superconducting technology with local (Ohio) and other companies for the development of local high technology industries. As part of the efforts of this center, larger scale testing facilities are available. Conductor development, persistent joint development, and superconducting magnets for Magnetic Resonance Imaging and other specialty applications are being co-developed with local industry.

CSMM QUICK FACTS

Founded in 1995
Focuses on applied superconductivity

MATERIALS STUDIED

MgB₂
Nb₃Sn
YBCO
BSSCO-2212
Oxypnictides
Carbon Nanotubes

APPLICATIONS

Magnets for fusion (ITER tokamak)
Particle accelerators (Large Hadron Collider)
Magnets for MRI and NMR machines
Transmission cables
Fault-current limiters
Energy storage
Wind turbine generators

Within CSMM itself, extensive cryogenic, electrical transport, and magnetic measurement facilities are in use. Part of the Center for Superconducting and Magnetic Materials is the Superconducting Technology Center (SuTC). This center has the aim of encouraging the development of superconducting technology with local (Ohio) and other companies for the development of local high technology industries. As part of the efforts of this center, larger scale testing facilities are available. Conductor development, persistent joint development, and superconducting magnets for Magnetic Resonance Imaging and other specialty applications are being co-developed with local industry.

PPMS With Helium Reliquification: A Quantum Design PPMS allows not only (a) VSM measurements from 4 K to room temperature in fields up to 14 T but (b) heat capacity (c) AC and DC susceptibility (d) AC transport and (e) thermal conductivity. The helium reliquifier attached allows us to minimize helium usage, an important cost control.

Neocera PLD: Neocera Pioneer 180 Complete PLD Laboratory, Includes: Lambda Physik COMPex Pro 102 Laser. 18" spherical vacuum chamber, Automated Six target carrousel with computer controlled, target rastering, 2" radiant substrate heater package with substrate rotation, oxygen compatible, Auto-tuning temperature controller, maximum temperature at substrate: 850C - 150 l/s or better turbopump package, base pressure: <9E-07 torr.

Magnetization Measurement: Magnetization may be measured by vibrating sample magnetometry (VSM) in three test stands other than the PPMS. Low Field VSM-I, a LDJ Model 9300 instrument with a 1 T iron-core electromagnet. Low Field VSM-II consisting of a PAR EG&G Model 4500 VSM associated with Janis Varitemp dewars (both liquid helium and liquid nitrogen) and an iron-core electromagnet energized to 1.5 T1.7 T by a Tidewater 65A power supply. High Field VSM also consisting of a PAR EG&G Model 4500 VSM associated with an Oxford cryostat housing a 6.4 cm (cold bore) 9 T superconducting solenoid.

Cryogen Free Magnet for Small Scale Transport Measurements: Room Temperature Bore Cryocooled Magnet. This cryocooled magnet with a field of 9 T in a 60 mm diameter room temperature bore of is be capable of accepting a furnace for magnetic field processing or a varitemp (presently on hand) for property measurement as function of field and temperature.

Heat Treatment Stations: A number of furnaces are available, both lower temperature range (800-900C) and higher temperature 1250 C are used, either with flowing argon, open air, or flowing oxygen.

Powder Processing Stations: Spex mills, a glove box, and encapsulation rigs are used for fabricating of new superconducting compounds.

High Temperature/High Pressure Induction Furnace: A high temperature (2200C) and moderate pressure (1500 psi) furnace which uses RF induction is used to study the phase diagram of superconducting materials.

High Field Magnet Set Up For Transport Property Measurement: High-Current High-Field Jc Measurement is carried out with currents of up to 1,700 A provided by a stack of three HP6681A (0- 8V, 0-580A) power supplies in the field of an Oxford hybrid NbTi/Nb3Sn solenoid excited by an Oxford Model PS120-10 magnet power supply. The maximum field available is 15 T at 4.2 K and 17 T at 2.2 K. We are using a high-current probe with a soldered ITER barrel mounting procedure and with monitored contact resistances. Temperature dependent Jc is measured at currents of up to 220 A in an exchange gas can inserted in the bore of the above Oxford solenoid. Resistive Critical Field (Hirr and Hc2) measurements are made at currents of about 10 mA in a dedicated exchange-gas can also able to be located in the bore of the Oxford solenoid. All instruments are under computer control with programs written in LabView.

Large Capacity Cryocooled Cryostat: Multi-purpose for testing large coils (4 ‘ diameter x 2’ deep), fault current limiter coils, or other coils/systems. Includes Large cryocooled box, two cryocoolers, Large power Supply, Roots Blower, smaller power supplies, nanovoltmeters and instrumentation, specially designed software.

Quench Measurement Station: This system consists of a A/D board connected to input amplifiers, read by a computer using Labview and associated software. There are sixteen input channels, each with a 16 bit resolution (full scale is divided in 65536 steps) on the A/D board, +/-5V full scale (when used with input amplifiers). The input amplifiers have a gain that can be set from 1 to 2000, giving an input resolution of 10V/2000/65536=~0.076microV, or about 80 nV. The response time is limited only by the 10kHz filter at input of amplifier, leading to a time resolution of 0.5 milliseconds. Presently there are two separate input amplifiers each serving 8 channels.

Transport Measurements of the Self-Field Critical Current of Large Devices: Available for the measurement of self-field critical current in large coils can is a large open-mouth dewar from Cryofab Inc. This has an inside diameter of 25 in (635 mm) and a working height (below a 18 in, 460 mm, thick plug) of 35 in ((890 mm). Measurements are made as function of temperature above 4 K as the internal structures slowly warm up. Self-field is monitored with a Hall probe.

AC Loss Measurement: Two test stands are housed in a laboratory dedicated to AC loss measurement. Self-Field (Transport-Current) Loss due to AC currents of up to 150 A (peak) at frequencies of up to 500 Hz is measured at 77 K (liquid nitrogen). A lock-up amplifier measures the voltage of the sample in-phase with transport current. External-Field AC Loss is measured in the applied fields of copper wound solenoids and race-track coils of various sizes. A system of pick-up coils connected to a digital oscilloscope records the samples' M-H loops whose areas provide a measurement of the loss per cycle.

Modelling Capabilities: CSMM’s modeling capabilities include high performance computing access to OSU’s supercomputer if needed, and a strong array of FEM software on local machines, including AYNSIS, FEMLAB, Flux 3D, and Flex PDE.

CSMM has ongoing interactions with many university and national laboratories, both here and abroad, as well as with a number of industrial partners.

A longstanding collaboration is in place with the low temperature group of the University of Twente, Netherlands (15 years – AC loss in cables). A similarly long collaboration is ongoing with Berkeley National Laboratory (15+ years – AC loss in cables). Interactions (15 years) with S.X. Dou from the materials department at the University of Wollongong, Australia have included Bi2223, and MgB2 as topics. Also, there has been a strong collaboration with the Wright Patterson based AFRL group working on superconducting materials (PLD YBCO, 6 years).

Recently initiated collaborations include; Fermilab (3 years – cable stability), the University of Manchester, UK (S. Smith, EE, Fault current limiters), and the Physics Department of the Southeast University of China (Pnictides).

Past collaborations have included: U. Pittsburgh (USA-Bi-materials), University of Houston (USA-YBC), CSIRO (Australia-thin films), KEK National Laboratory for High Energy Physics (Japan-AC loss in cables), NIST (USA-LTSC, VAMAS standards), Argonne (USA-BSCCO), NRIM (Japan-VAMAS round robins and Nb3Al processing), the Electrotechnical Institute (Bratislava, Slovakia – Synergistic pinning effects), Yamaguchi University (Japan-Nb3Al studies), the Tsukuba Magnet Laboratory (Japan – Nb3Al), and the Atom-Institute (Austria – Nb3Al and MgB2).

Industrial collaborators have included: IGC-Advanced Superconductors (USA-BSCCO, Nb3Al, Nb3Sn, NbTi, NbTiTa), Plastronics (USA-BSCCO), Supercon (USA-Nb3Al), Microcoating Technology (USA-Bi-materials and coatings), Oxford Superconductors (USA -- Bi-materials and coatings) Innovare (USA-Nb3Al), Ceram Physics (YBCO), Supergenics (Nb3Sn), Supramagnetics (Nb3Sn and Bi-2212), Seimens, Rolls Royce (Fault current limiters).

There has been a particularly strong and effective collaboration with the locally based Hyper Tech Research (USA – Nb3Al, Nb3Sn) (OSU was associated with its start up). Other local companies include Global R&D, M2M imaging, and Eden Cryogenics.

M Majoros, M D Sumption, E W Collings and D van der Laan, “ Stability and normal zone propagation in YBCO CORC cables”, Supercond. Sci. Technol. 29 (2016) 044006.
X. Xu and M. D. Sumption, “A model for the compositions of non-stoichiometric intermediate phases formed by diffusion reactions, and its application to Nb3Sn superconductors”, Scientific Reports 6:19096 (2016) DOI: 10.1038/srep19096
H.S. Kim, M.D.Sumption, M.A.Susner, H.Lim, E.W.Collings, Bulge testing of copper and niobium tubes for hydroformed RF cavities”, Materials Science &Engineering A654 (2016) 13–20.
R.Morrow, J.R.Soliz, A.J.Hauser, J.C.Gallagher, M.A.Susner, M.D.Sumption, A.A.Aczel, J.Yan, F.Yang, P.M.Woodward, “The effect of chemical pressure on the structure and properties of A2CrOsO6 (A=Sr,Ca) ferromagnetic double perovskite”, Journal of Solid State Chemistry 238 (2016) 46–52.
H. S. Kim, C. Kovacs, M. Rindfleisch, J. Yue, D. Doll, M. Tomsic, M. D. Sumption, and E. W. Collings, “Demonstration of a Conduction Cooled React and Wind MgB2 Coil Segment for MRI Applications”, IEEE Trans. Appl. Supercond. 26 (2016) 4400305.
R. Morrow, M. A. Susner, M. D. Sumption, and P. M. Woodward, “Magnetic structure of the quasi-one-dimensional La3OsO7 as determined by neutron powder diffraction”, Phys. Rev. B 92, 134402 (2015).
Y.Yang, G.Li, M.Susner, M.D.Sumption, M.Rindfleisch, M.Tomsic, E.W.Collings, “Influence of twisting and bending on the Jc and n-value of multifilamentary MgB2 strands”, Physica C (2015)118–123.
G.Z. Li, M.A. Susner, S.D. Bohnenstieh, M.D. Sumption, E.W. Collings, “Microstructures and superconducting properties of high performance MgB2 thin films deposited from a high-purity, dense Mg–B target”, Applied Surface Science 357 (2015) 452–458.
G. Li, M.D. Sumption, and E.W. Collings, “Kinetic Analysis of MgB₂ Layer Formation in Advanced Internal Magnesium Infiltration (AIMI) Processed MgB₂ Wires”, Acta Materialia, 96 (20150901): 66-71
E. W. Collings, M. D. Sumption, M. Majoros, X. Wang, and D. R. Dietderich, “Effects of Core Type, Placement, and Width, on the Estimated Interstrand Coupling Properties of QXF-Type Nb3Sn Rutherford Cables”, IEEE Trans. Appl. Supercon. 25 (2015) 4802805, DOI: 10.1109/TASC.2015.2390628
M. Majoros, M. Sumption, E.W. Collings, and N. Long, “Inter-strand Current Sharing and AC Loss Measurements in Superconducting YBCO Roebel Cables" Superconductor Science and Technology, v28 n5 (20150501): 055010
C. S. Myers, H. Miao, Y. Huang, M. D. Sumption, and E. W. Collings, “Reduced Magnetization and Loss In Ag-Mg Sheathed Bi2212 wires: Systematics With Sample Twist Pitch and Length”, IEEE Trans. Appl. Supercon. 25 (2015) 8201604, DOI: 10.1109/TASC.2014.2372614
N. P. Bansal , J. C. Goldsby, R. B. Rogers, M. A. Susner, M. D. Sumption”, Chemical Synthesis of Superconducting MgB2 Nanopowder”, Journal of Alloys and Compounds 622 (2015) 986–988.
X. Wang, G. Ambrosio, G. Chlachidze, E. W. Collings, D. R. Dietderich, J. DiMarco, H. Felice, A. K. Ghosh, A. Godeke, S. A. Gourlay, M. Marchevsky, S. O. Prestemon, G. Sabbi,M. D. Sumption, G. V. Velev, X. Xu, and A. V. Zlobin, “Validation of Finite-Element Models of Persistent-Current Effects in Nb3Sn Accelerator Magnets”, IEEE Trans. Appl. Supercond. 25, (2015) 4003006.
X. Xu, M. Majoros, M. D. Sumption, and E. W. Collings, “Persistent-Current Magnetization of Nb3Sn Strands: Influence of Applied Field Angle and Transport Current”, IEEE Trans. Appl. Supercond. 25 (2015) 8200704.
X. Xu , M. D. Sumption, and X. Peng, “Internally Oxidized Nb3Sn Strands with Fine Grain Size and High Critical Current Density”, Adv. Mater. 2015, 27, 1346–1350.
N. W. Khun, G. S. Frankel, and M. Sumption, “Effects of Normal Load, Sliding Speed, and Surface Roughness on Tribological Properties of Niobium under Dry and Wet Conditions”, Tribology Transactions, 57: 944-954, 2014
S.D. Bohnenstiehl, M.A. Susner, S.A. Dregia, M.D. Sumption, J. Donovan, E.W. Collings”, Experimental Determination of the Peritectic Transition Temperature of MgB2 in the Mg–B Phase Diagram”, Thermochimica Acta 576 (2014) 27– 35.
M Majoros, M D Sumption, E W Collings and D C van der Laan, “Magnetization losses in superconducting YBCO conductor-on-round-core (CORC) cables”, Supercond. Sci. Technol. 27 (2014) 125008 (12pp); doi:10.1088/0953-2048/27/12/125008.
X Xu, M D Sumption and E W Collings, “Influence of heat treatment temperature and Ti doping on low-field flux jumping and stability in (Nb-Ta)3Sn strands”, Supercond. Sci. Technol. 27 (2014) 095009 (10pp); doi:10.1088/0953-2048/27/9/095009.
C Zhou, P Gao, H J G Krooshoop, M Dhallé, M D Sumption, M Rindfleisch, M Tomsic, M Kulich, C Senatore and A Nijhuis, “Intrawire resistance, AC Loss and Strain Dependence of Critical Current in MgB2 Wires with and without Cold High-Pressure Densification”, Supercond. Sci. Technol. 27 (2014) 075002 (5pp) doi:10.1088/0953-2048/27/7/075002.
M A Susner, M D Sumption, A Takase and E W Collings, “Evidence for Zr Site-Substitution for Mg in PLD-deposited MgB2 Thin Films”, Supercond. Sci. Technol. 27 (2014) 075009 (7pp); doi:10.1088/0953-2048/27/7/075009.
M.A.Susner, S.D.Carnevale, T.F.Kent, L.M.Gerber, P.J.Phillips, M.D. Sumption, R.C.Myers, “Catalyst-free ZnO Nanowires on Silicon by Pulsed laser Deposition with Tunable Density and Aspect Ratio”, Physica E 62 (2014) 95–103.
T. L. Meyer, M. Dixit, R. E. A. Williams, M. A. Susner, H. L. Fraser, D. W. McComb, M. D. Sumption, T. R. Lemberger, and P. M. Woodward, “Cation non-stoichiometry in Pulsed Laser Deposited Sr2+yFe1+xMo1-xO6 Epitaxial Films”, J. Appl. Phys. 116, 013905 (2014); doi: 10.1063/1.4885450
M. Majoros, M. D. Sumption, E. W. Collings, and N. J. Long, “Stability, Inter-Strand Contact Resistance, and AC Losses in YBCO Roebel Cables, IEEE Trans. Appl. Supercond. 24 (2014) 6600505.
G. Li, J. B. Zwayer, C. J. Kovacs, M. A. Susner, M. D. Sumption, M. A. Rindfleisch, C. J. Thong, M. Tomsic, and E. W. Collings, “Transport Critical Current Densities and n-Values of Multifilamentary MgB2 Wires at Various Temperatures and Magnetic Fields”, IEEE Trans. Appl. Supercond. 24 (2014) 6200105.
E. W. Collings, M. A. Susner, M.D. Sumption, and D. R. Dietderich, “Extracted Strand Magnetizations of an HQ Type Nb3Sn Rutherford Cable and Estimation of Transport Corrections at Operating and Injection Fields”, IEEE Trans. Appl. Supercond. 24 (2014) 4802605.
X. Xu, E. Collings, M. Sumption, C. Kovacs, and X. Peng, “The Effects of Ti Addition and High Cu/Sn Ratio on Tube Type (Nb, Ta)3Sn Strands, and a New Type of Strand Designed to Reduce Unreacted Nb Ratio”, IEEE Trans. Appl. Supercond. 24 (2014) 6000904
M. A. Susner, S. D. Bohnenstiehl, S. A. Dregia, M. D. Sumption, Y. Yang, J. J. Donovan, and E. W. Collings, “Homogeneous carbon doping of magnesium diboride by high-temperature, high-pressure synthesis”, Applied Physics Letters 104, 162603 (2014); doi: 10.1063/1.4871578
X. Xu, M. Sumption, X. Peng, and E. W. Collings, “Refinement of Nb3Sn grain size by the generation of ZrO2 precipitates in Nb3Sn wires”, Applied Physics Letters 104, 082602 (2014); doi: 10.1063/1.4866865
G. Z. Li, M. D. Sumption, M. A. Rindfleisch, C. J. Thong, M. J. Tomsic, and E. W. Collings, “Enhanced higher temperature (20–30 K) transport properties and irreversibility field in nano-Dy2O3 doped advanced internal Mg infiltration processed MgB2 composites”, Applied Physics Letters 105, 112603 (2014); doi: 10.1063/1.4896259
N. W. Khun, M. Sumption, G. S. Frankel, “Smoothening of niobium by electropolishing”, J Appl Electrochem (2013) 43:829–838.
M.A. Susner, M.D. Sumption, M.A. Rindfleisch, E.W. Collings, “Critical current densities of doped MgB2 strands in low and high applied field ranges: The Jc(B) crossover effect”, Physica C 490 (2013) 20–25.
F.F. Yuan, Y. Ding, Y. Sun, J.C. Zhuang, W. Zhou, G.Z. Li, M. Sumption, X.W. Li, Z.X. Shi, “Effects of oxide precursors on superconducting properties of polycrystalline SmFeAsO1-xFx“, Physica C 495 (2013) 198–201.
G Z Li, M D Sumption, J B Zwayer, M A Susner, M A Rindfleisch, C J Thong, M J Tomsic and E W Collings, “Effects of carbon concentration and filament number on second generation internal Mg diffusion MgB2 strands”, Supercond. Sci. Technol. 26 (2013) 095007.
X Xu, M D Sumption and E W Collings", A Model for Phase Evolution and Volume Expansion in Tube Type Nb3Sn Conductors”, Supercond. Sci. Technol. 26 (2013) 125006
X Xu, M D Sumption, S Bhartiya, X Peng, and E W Collings, "Critical current densities and microstructures in Rod-in-Tube and Tube Type Nb3Sn strands – Present status and prospects for improvement”, Supercond. Sci. Technol. 26 (2013) 075015
C. Zhou, W. Offringa, A. Bergen, W.A..J. Wessel, H. J. G. Krooshoop, M. Dhall´e, M.D. Sumption, E.W. Collings, M. Rindfleisch, M. Tomsic, H.H. J. ten Kate and A. Nijhuis, “Intra-Wire Resistance and AC Loss in Multi-Filamentary MgB2 Wires”, Supercond. Sci. Technol. 26 (2013) 025002.
G. Z. Li, K. M. Reddy, J. B. Zwayer, M. A. Kuldell, M. A. Susner, Y. Yang, M. D. Sumption, J. J. Yue, M. A. Rindfleisch, M. J. Tomsic, C. J. Thong, and E. W. Collings, “Critical Current Density and Current Transfer Length of Multifilamentary MgB2 Strands of Various Design”, IEEE Trans. Appl. Supercond. 23 (2013) 6200204.
C. S. Myers, M. A. Susner, L. Motowidlo, J. Distin, M. D. Sumption, and E. W. Collings, “Specific Heats of Composite Bi2212, Nb3Sn, and MgB2 Wire Conductors”, IEEE Trans. Appl. Supercond. 23 (2013). 8800204
M. Kanuchova, M. Majoros, J. Kanuch, Y. Ding, M. A. Susner, M. D. Sumption, and E. W. Collings, “LiFeAs Pnictide Superconductor—A Simple Electrochemical Method of Preparation”, IEEE Trans. Appl. Supercond, 23 (2013) 7300204.
E. W. Collings, M. D. Sumption, M. A. Susner, D. R. Dietderich, E. Kroopshoop, and A. Nijhuis, “Coupling- and Persistent-Current Magnetizations of Nb3Sn Rutherford Cables With Cores of Stainless Steel and Woven Glass-Fiber Tape Measured by Pick-Up Coil Magnetometry”, IEEE Trans. Appl. Supercond, 23 (2013) 4702305.
J. P. Murphy, M.J. Mullins, P.N. Barnes, T.J. Haugan, G.A. Levin, M.Majoros, M.D. Sumption, E. W. Collings, M. Polak, and P. Mozola, “ Experiment Setup for Calorimetric Measurements of Losses in HTS Coils Due to AC Current and External Magnetic Fields”, IEEE Trans. Appl. Supercond, 23 (2013) 4701505.
H. S. Kim, M. D. Sumption, H. Lim, and E. W. Collings, “Evaluation of Mechanical Properties of Tubular Materials with Hydraulic Bulge Test for Superconducting Radio Frequency (SRF) Cavities”, IEEE Trans. Appl. Supercond, 23 (2013) 3500604.
A. Chandra, M. Sumption, G.S. Frankel, “On the mechanism of niobium electropolishing, Journal of the Electrochemical Society, v159 n11 (2012 12 01): C485-C491.
M.A Susner, T.W. Daniels, M.D. Sumption, M.A. Rindfleisch, C.J. Thong and E.W. Collings, Drawing Induced Texture and the Evolution of Superconductive Properties with Heat Treatment Time in Powder-in-tube in-situ Processed MgB2 Strands”, Supercond. Sci. Technol. 25 (2012) 065002 (13pp).
G Z Li, Y Yang, M A Susner, M D Sumption and E W Collings, “Critical Current Densities and n-values of MgB2 Strands over a Wide Range of Temperatures and Fields”, Supercond. Sci. Technol. 25 (2012) 025001 (10pp).
A.J. Hauser, J. R. Soliz, M. Dixit, R.E.A. Williams, M. A. Susner, B. Peters, L.M. Mier, T. L. Gustafson, M.D. Sumption, H.L. Fraser, P.M. Woodward, and F.Y. Yang, “Fully Ordered Sr2CrReO6 Epitaxial Films: A High-temperature Ferrimagnetic Semiconductor, Phys. Rev. B 85, 161201(R) (2012).
E. W. Collings, M.D. Sumption, M. A. Susner, D. R. Dietderich, E. Krooshoop and A. Nijhuis, “Interstrand Contact Resistance and Magnetization of Nb3Sn Rutherford Cables with Cores of Different Materials and Widths”, IEEE Trans. Appl. Supercond. 22 (2012).
Y. Yang, M.A. Susner, M.D. Sumption, M. Rindfleisch, M. Tomsic, and E.W. Collings, “Influence of Strand Design, Boron Type, and Carbon Doping Method on the Transport Properties of Powder-in-Tube MgB2−XCX Strands”, IEEE Trans. Appl. Supercond. 22 (2012) 6200110.
M.D. Sumption, S. Bhartiya, C. Kovacks, X. Peng, E. Gregory, M.J. Tomsic, E.W. Collings, “Critical Current Density and Stability of Tube Type Nb3Sn Conductors”, Cryogenics 52 (2012) 91–99.
M.A. Susner, Y. Yang, M.D. Sumption, E.W. Collings, M.A. Rindfleisch, M.J. Tomsic and J.V. Marzik, “RAPID COMMUNICATION: Enhanced Critical Fields and Superconducting Properties of Pre-doped B Powder-Type MgB2 Strands”, Supercond. Sci. Technol. 24 (2011) 012001 (5pp).
Y. Ding, Y. Sun, J.C. Zhuang, L.J. Cui, Z.X. Shi, M.D. Sumption, M. Majoros,M.A. Susner, C.J. Kovacs, G.Z. Li, E.W.Collings and Z.A. Ren, “Density Effect on Critical Current Density and Flux Pinning Properties of Polycrystalline SmFeAsO1−xFx Superconductor”, Supercond. Sci. Technol. 24 (2011) 125012 (7pp).
Z.X. Shi, M.A. Susner, M.D. Sumption, E.W. Collings, X. Peng, M. Rindfleisch and M.J. Tomsic, “Doping effect and flux pinning mechanism of nano-SiC additions in MgB2 strands” Supercond. Sci. Technol. 24 (2011) 065015 (7pp).
S.D. Bohnenstiehl, M.A. Susner, Y. Yang, E.W. Collings, M.D. Sumption, M.A. Rindfleisch, R. Boone, “Carbon Doping of MgB2 by Toluene and Malic-Acid-in-Toluene”, Physica C 471 (2011) 108–111.
M. Majoros, M. D. Sumption, and E. W. Collings, “Stability and Normal Zone Propagation in a 50 Tesla Solenoid Wound of YBCO Coated Conductor Tape – FEM Modeling”, IEEE Trans. Appl. Supercond. 99 (2011) 1.
M. Majoros, M. D. Sumption, M. A. Susner, E. W. Collings, J. Souc, F. Gomory, M. Vojenciak, L. M. Fisher, A. V. Kalinov, and I. F. Voloshin, “AC Magnetization Loss of a YBCO Coated Conductor Measured Using Three Different Techniques”, IEEE Trans. Appl. Supercond. 21 (2011) 3293-3296.
M. Majoros, M. Kanuchova, M. A. Susner, M. D. Sumption, C. S. Myers, S. D. Bohnenstiehl, and E. W. Collings, “Effects of Heat Treatments on the Properties of SmFeAsO1-xFx Oxypnictide Bulks Prepared via a Single-Step Route”, IEEE Trans. Appl. Supercond. 21 (2011) 2853-2857.
C. S. Myers, M. A. Susner, L. Motowidlo, J. Distin, M. D. Sumption, and E. W. Collings, “Transport, Magnetic, and SEM Characterization of a Novel Design Bi-2212 Strand”, IEEE Trans. Appl. Supercond. 21 (2011) 2804-2807.
X. Peng, E. Gregory, M. Tomsic, M. D. Sumption, A. Ghosh, X. F. Lu, N. Cheggour, T. C. Stauffer, L. F. Goodrich, and J. D. Splett, “Strain and Magnetization Properties of High Subelement Count Tube-Type Nb3Sn Strands”, IEEE Trans. Appl. Supercond. 21 (2011) 2559-2562.
M. G. T. Mentink, A. Anders, M. M. J. Dhalle, D. R. Dietderich, A. Godeke, W. Goldacker, F. Hellman, H. H. J. ten Kate, D. Putnam, J. L. Slack, M. D. Sumption, and M. A. Susner, “Analysis of Bulk and Thin Film Model Samples Intended for Investigating the Strain Sensitivity of Niobium-Tin”, IEEE Trans. Appl. Supercond. 21 (2011) 2550-2553.
E. W. Collings, M. D. Sumption, M. A. Susner, D. R. Dietderich, and A. Nijhuis, “Coupling Loss, Interstrand Contact Resistance, and Magnetization of Nb3Sn Rutherford Cables With Cores of MgO Tape and S-Glass Ribbon”, IEEE Trans. Appl. Supercond. 21 (2011) 2367-2371.
M. Majoros, M. D. Sumption, E.W. Collings, and M. Tomsic, “Design of a Nb3Sn-Based Short Period Model Superconducting Helical Undulator”, IEEE Trans. Appl. Supercond. 21 (2011) 1713-1716.
L.S. Lakshmi, M.P. Staines, R.A. Badcock, N.J. Long, M. Majoros, E.W. Collings and M.D. Sumption, “Frequency Dependence of Magnetic AC Loss in a Roebel Cable Made of YBCO on a Ni–W substrate”, Supercond. Sci. and Tech. 23 (2010) 085009.
M.D. Sumption, M. Majoros, M. Susner, D. Lyons, X .Peng, C.F. Clark, W.N. Lawless and E.W. Collings, “Thermal Diffusion and Quench Propagation in YBCO Pancake Coils Wound with ZnO and Mylar Insulations”, Supercond. Sci. and Tech. 23 (2010) 075004.
Z.X. Shi, M.A. Susner, M. Majoros, M.D. Sumption, X. Peng, M. Rindfleisch, M.J. Tomsic and E.W. Collings, “Anisotropic Connectivity and its Influence on Critical Current Densities, Irreversibility Fields, and Flux Creep in in-situ Processed MgB2 Strands, “Supercond. Sci. Tech. 23 (2010)-045018.
E.W. Collings, M.D. Sumption, M.A. Susner, E. Barzi, D. Turrioni, R. Yamada, A.V. Zlobin, and A. Nijhuis, “Coupling- and Persistent-Current Magnetizations of Nb3Sn Rutherford Cables”, IEEE Trans. Appl. Supercond. 20, (2010) 1387.
M. Majoros, M. D. Sumption, M. A. Susner, S. Bhartiya, M. Mahmud, E. W. Collings, M. Tomsic, M. Rindfleisch, J. Phillips, D. Lyons, and J. Yue, “A Nb3Sn-Based, Model Superconducting Helical Undulator Fabricated Using a Wind and React Process”, IEEE Trans. Appl. Supercond. 20, (2010) 270.
M. A. Susner, M. Bhatia, M. D. Sumption, and E. W. Collings, “Electrical resistivity, Debye temperature, and connectivity in heavily doped bulk MgB2 superconductors”, . Appl. Phys. 105, 103916 (2009).
Y.S. Hascicek, Y.Akin, T.W. Baldwin, M.M. Rindfleisch, J. Yue, M.D. Sumption and M Tomsic, “An MgB2 12.5 kVA superconductor transformer”, Supercond. Sci. Technol. 22 065002 (2009).
M. Majoros, Mike D. Sumption, M. A. Susner, M. Tomsic, M. Rindfleisch, and E. W. Collings, “AC Losses in MgB2 Multifilamentary Strands With Magnetic and Non-Magnetic Sheath Materials”, IEEE Trans. Appl. Supercond. 19 3106 (2009).
M. A. A. Mahmud, Mike A. Susner, Mike D. Sumption, Matthew A. Rindfleisch, Michael J. Tomsic, Jinji Yue, and Edward W. Collings, “Comparison of Critical Current Density in MgB2 With Different Boron Sources and Nano-Particle Dopant Additions”, IEEE Trans. Appl. Supercond. 19 2756 (2009).
S. Bhartiya, Mike D. Sumption, Xuan Peng, Eric Gregory, Michael J. Tomsic, and Edward W. Collings, “Investigation of the Effects of Low Temperature Heat Treatments on the Microstructure and Properties of Multifilamentary, Tube-Type Nb3Sn Strands”, IEEE Trans. Appl. Supercond. 19 2588 (2009).
M. Majoros, M. D. Sumption, E. W. Collings, and David Doll, “Numerical Modeling of the AC Limiting Properties of Insulated, Conduction Cooled MgB2 Strands”, IEEE Trans. Appl. Supercond. 19 1872 (2009).
Milan Majoros, Mike D. Sumption, and Edward W. Collings, “Transport AC Loss Reduction in Striated YBCO Coated Conductors by Magnetic Screening”, IEEE Trans. Appl. Supercond. 19 3352 (2009).
T.J. Haugan, F.J. Baca, M.J. Mullins, N.A. Pierce, T.A. Campbell, E.L. Brewster, P.N. Barnes, H. Wang, and M. D. Sumption, “Temperature and Magnetic Field Dependence of Critical Current Density of YBCO with Varying Flux Pinning Additions”, IEEE Trans. Appl. Supercond. 19 3270 (2009).
E.Gregory, M. Tomsic, X. Peng, M.D. Sumption, and A. Ghosh, “Nb3Sn Superconductors Made by an Economical Tubular Process”, IEEE Trans. Appl. Supercond. 19 2602 (2009).
M.D. Sumption, M. Susner, E.W. Collings, D.R. Dietderich, E. Barzi, D. Turrioni, R. Yamada, and A.V. Zlobin, “Effect of Cable Edge Deformation on RRR and Magnetization of Strands Extracted From Nb3Sn Rutherford-Type Cables”, IEEE Trans. Appl. Supercond. 19 2481 (2009).
M. Majoros, M. D. Sumption, M. A. Susner, S. Bhartiya, S. D. Bohnenstiehl, E. W. Collings, M. Tomsic, M. Rindfleisch, J. Phillips, D. Lyons, and J. Yue, “A Model Superconducting Helical Undulator Wound Using a Wind and React MgB2 Multifilamentary Wire”, IEEE Trans. Appl. Supercond. 19 1376 (2009).
M.D. Sumption, T.J. Haugan, P.N. Barnes, T.A. Campbell, N.A. Pierce, and C. Varanasi, “Magnetization Creep and Decay in YBa2Cu3O7−x Thin Films with Artificial Nanostructure Pinning, Phys. Rev. B 77, 094506 (2008).
E.W. Collings, M.D. Sumption, M. Bhatia, M.A. Susner and S.D. Bohnenstiehl, “Prospects for Improving the Intrinsic and Extrinsic Properties of Magnesium Diboride Superconducting Strands”, Supercond. Sci. Technol. 21 103001 (2008).
R. Zeng, L. Lu, W. X. Li, J. L. Wang, D. Q. Shi, J. Horvat, S.X. Dou, M. Bhatia, M. Sumption, E. W. Collings, J. M. Yoo, M. Tomsic, and M. Rindfleisch, “Excess Mg Addition MgB2 /Fe Wires with Enhanced Critical Current Density”, Journal of Applied Physics 103, 083911 (2008).
E.W. Collings, M.D. Sumption, E. Barzi, D. Turrioni, R. Yamada, A.V. Zlobin, Y. Ilyin, and A. Nijhuis, “Effect of Core Width, Placement, and Condition on Calorimetrically Measured AC Loss and Interstrand Contact Resistance of Stainless-Steel-Cored Nb3Sn Rutherford Cables”, IEEE Trans. Appl. Supercond. 18 1370 (2008).
D. Turrioni, E. Barzi, M. Bossert, E.W. Collings, V. Nazareth, M.D. Sumption, R. Yamada, and A.V. Zlobin, “Effects of Rutherford Cable Parameters on Nb3Sn Extracted Strand Deformation and Performance”, IEEE Trans. Appl. Supercond. 18 1114 (2008).
E. Gregory, M. Tomsic, X. Peng, R. Dhaka, V.R. Nazareth, and M.D. Sumption, “Niobium Tin Conductors for High Energy Physics, Fusion, MRI and NMR Applications Made by Different Techniques”, IEEE Trans. Appl. Supercond. 18 989 (2008).
E.W. Collings, M.D. Sumption, M.A. Susner, D.R. Dietderich, E. Barzi, A.V. Zlobin, Y. Ilyin, and A. Nijhuis, “Influence of a Stainless Steel Core on Coupling Loss, Interstrand Contact Resistance, and Magnetization of an Nb3Sn Rutherford Cable”, IEEE Trans. Appl. Supercond. 18 1301 (2008).
V.R. Nazareth, M.D. Sumption, X. Peng, E. Gregory, M.J. Tomsic, and E.W. Collings, “Characterization of the A15 Layer Growth and Microstructure for Varying Heat Treatments in Nb3Sn Tube Type Composites”, IEEE Trans. Appl. Supercond. 18 1005 (2008).
M. Tomsic, M. Rindfleisch, J.J. Yue, K. McFadden, J. Phillips, M.D. Sumption, M. Bhatia, S. Bohnenstiehl, and E.W. Collings, “Overview of MgB2 Superconductor Applications”, Int. J. Appl. Ceramic Tech. 4 250-259 (2007).
M. Tomsic, M. Rindfleisch, J.J. Yue, K. McFadden, D. Doll, J. Phillips, M.D. Sumption, M. Bhatia, S. Bohnenstiehl, and E.W. Collings, “Development of Magnesium Diboride (MgB2) Wires and Magnets Using in-situ Strand Fabrication Method”, Physica C 456 203-208 (2007).
M.A. Susner, M.D. Sumption, M. Bhatia, X. Peng, M. Tomsic, M.A. Rindfleisch, and E.W., Collings, “Influence of Mg/B Ratio and SiC Doping on Microstructure and High Field Transport J(c) in MgB2 strands”, Physica C 456 180-187 (2007).
M.D. Sumption, M. Bhatia, F. Buta, S. Bohnenstiehl, M. Tomsic, M. Rindfleisch, J. Yue, J. Phillips, S. Kawabata, and E.W. Collings, “Multifilamentary MgB2-Based Solenoidal and Racetrack Coils”, Physica C 458 12-20 (2007).
M.S.A. Hossain, J.H. Kim, X. Xu, X.L. Wang, M. Rindfleisch, M. Tomsic, M.D. Sumption, E.W. Collings, and S.X. Dou, “Significant Enhancement of Hc2 and Hirr in MgB2+C4H6O5 Bulks at a Low Sintering Temperature of 600 Degrees C” Supercond. Sci. Tech. 20 L51-L54 (2007).
M.D. Sumption, M.A. Susner, M. Bhatia, M.A. Rindfleisch, M.J. Tomsic, K.J. McFadden, and E.W. Collings, “High Critical Current Density Multifilamentary MgB2 Strands”, IEEE Trans. Appl. Supercond. 17 2838-2841 (2007).
M. Eisterer, K.R. Schoppl, H.W. Weber, M.D. Sumption, and M. Bhatia, “Neutron Irradiation of SiC Doped and Magnesium Rich MgB2 Wires” IEEE Trans. Appl. Supercond. 17 2814-2817 (2007).
S. Bohnenstiehl, S.A. Dregia, M.D. Sumption, and E.W. Collings, “Thermal Analysis of MgB2 Formation IEEE Trans. Appl. Supercond. 17 2754-2756 (2007).
M. Bhatia, M.D. Sumption, S. Bohnenstiehl, S.A. Dregia, E.W. Collings, M. Tomsic, and M. Rindfleisch, “Superconducting Properties of SiC Doped MgB2 Formed Below and Above Mg's Melting Point”, IEEE Trans. Appl. Supercond. 17 2750-2753 (2007).
M.D. Sumption and E.W. Collings, “Modeling Current-Field Instabilities in High Performance Nb3Sn Strands in Moderate Field”, IEEE Trans. Appl. Supercon. 17 2714-2717 (2007).
X. Peng, M.D. Sumption, R. Dhaka, M. Bhatia, M. Tomsic, E. Gregory, and E.W. Collings, “Composition Profiles and Upper Critical Field Measurement of Internal-Sn and Tube-Type Conductors”, IEEE Trans. Appl. Supercon. 17 2668-2671 (2007).
E. Gregory, B.A. Zeitlin, M. Tomsic, X. Peng, M.D. Sumption, and E.W. Collings, “Some Factors Involved in the Development of a Tubular Process for Nb3Sn Conductors”, IEEE Trans. Appl. Supercond. 17 2664-2667 (2007).
R.K. Dhaka, M.D. Sumption, X. Peng, E. Gregory, M. Tomsic, and E.W. Collings, “Experimental and Theoretical Investigation of the Diffusion of Sn in Internal-Tin Nb3Sn”, IEEE Trans. Appl. Supercon. 17 2655-2659 (2007).
E.W. Collings, M.D. Sumption, G. Ambrosio, Y. Ilyin, an A. Nijhuis, “Interstrand Contact Resistance in Nb3Sn Cables Under LARP-Type Preparation Conditions” IEEE Trans. Appl. Supercond. 17 2494-2497 (2007).
M.D. Sumption, S.A. Bohnenstiehl, F. Buta, M. Majoros, S. Kawabata, M. Tomsic, M. Rindfleisch, J. Phillips, J. Yue, and E.W. Collings, “Wind and React and React and Wind MgB2 Solenoid, Race Track and Pancake Coils”, IEEE Trans. Appl. Supercond. 17 2286-2290 (2007).
M. Majoros, L. Ye, A.A. Campbell, T.A. Coombs, M.D. Sumption, and E.W. Collings, “Modeling of Transport AC Losses in Superconducting Arrays Carrying Anti-parallel Currents”, IEEE Trans. Appl. Supercond. 17 1803-1806 (2007).
M. Majoros, L. Ye, A.A. Campbell, T.A. Coombs, A.V. Velichko, D.M. Astill, P. Sargent, M. Haslett, M.D. Sumption, E.W. Collings, M. Tomsic, S. Harrison, and M. Husband, “Fault Current Limiting Properties of MgB2 Superconducting Wires” IEEE Trans. Appl. Supercond. 17 1764-1767 (2007).
M. Majoros, L. Ye, A.V. Velichko, T.A. Coombs, M.D. Sumption, and E.W. Collings, “Transport AC Losses in YBCO Coated Conductors”, Supercond. Sci. Tech. 20 S299-S304 (2007).
C.V. Varanasi, J. Burke, L. Brunke, H. Wang, M. Sumption, and P.N. Barnes, “Enhancement and Angular Dependence of Transport Critical Current Density in Pulsed Laser Deposited YBa2Cu3O7-x+BaSnO3 Films in Applied Magnetic Fields”, J. Appl. Phys. 102 063909 (2007).
M.D. Sumption, S. Kawabata, and E.W. Collings, “AC Loss in YBCO Coated Conductors Exposed to External Magnetic Fields at 50-200 Hz”, Physica C, 466 (1-2): 29-36 (2007).
Y. Iwasa, D.C. Larbalestier, M. Okada, R. Penco, M. D. Sumption, and X. Xi, “A Round Table Discussion on MgB2, Toward a Wide Market or a Niche Production?—A Summary”, IEEE Trans. Appl. Supercond. 16, 1457-1461 (2006).
E. W. Collings, S. Kawabata, M. Bhatia, M. Tomsic, and M. D. Sumption, “Magnesium Diboride Superconducting Strand for Accelerator and Light Source Applications”, IEEE Trans. Appl. Supercond. 16, 1445-1449 (2006).
E. W. Collings, M. D. Sumption, D. R. Dietderich, Y. Ilyin, and A. Nijhuis, “Magnetic Measurements of Interstrand Contact Resistance in Nb3Sn Cables in Response to Variation of Pre-Heat-Treatment Condition”, IEEE Trans. Appl. Supercond. 16, 1200-1204 (2006).
M.D. Sumption, M. Bhatia, M. Rindfleisch, M. Tomsic, E.W. Collings, “Transport Properties of Multifilamentary, in-situ route, Cu-Stabilized MgB2 Strands: one Metre Segments and the J(c)(B,T) Dependence of Short Samples”, Supercond. Sci. Tech. 19 155-160 (2006).
Shcherbakova, S.X. Dou, S. Soltanian, D. Wexler, M. Bhatia, M.D. Sumption, E.W. Collings, “The Effect of Doping Level and Sintering Temperature on Jc(H) Performance in Nano-SiC Doped and Pure MgB2 Wires”, J. Appl. Phys. 99 08M510 (2006).
P.N. Barnes, G.L. Rhoads, J.C. Tolliver, M.D. Sumption, and K.W. Schmaeman, “Compact, Lightweight, Superconducting Power Generators”, IEEE Transactions on Magnetics 41 268-273 (2005).
M.D. Sumption, M. Bhatia, X. Wu, M. Rindfleisch, M. Tomsic and E.W. Collings, “Multifilamentary, in-situ Route, Cu-Stabilized MgB2 Strands”, Supercond. Sci. Technol. 18 730-734 (2005).
S. Soltanian, X.L. Wang, J. Horvat, S.X. Dou, M.D. Sumption, M. Bhatia, E.W. Collings, P. Munroe, and M. Tomsic, “High Transport Critical Current Density and Large Hc2 and Hirr in Nanoscale SiC doped MgB2 Wires Sintered at Low Temperature”, Supercond. Sci. Technol. 18 658-666 (2005).
P.N. Barnes, T.J. Haugan, M.D. Sumption, and B.C Harrison, “Pinning Enhancement of YBa2Cu3O7-d Thin Films with Y2BaCuO5 Nanoparticulates”, IEEE Trans. Appl. Supercond. 15 3766-3769 (2005).
X. Peng, M.D. Sumption, and E.W. Collings, “Magnetization and deff in Multifilamentary Nb3Sn strands”, IEEE Trans. Appl. Supercond. 15 3498-3501 (2005).
E. Gregory, M. Tomsic, M.D. Sumption, X. Peng, X. Wu, E. W. Collings, and B. A. Zeitlin, “The Introduction of Titanium into Internal-Tin Nb3Sn by a Variety of Procedures”, IEEE Trans. Appl. Supercond.15 3478-3481 (2005).
X. Peng, M.D. Sumption, and E.W. Collings, “Finite Element Analysis of Drawing of Multifilamentary Wires”, IEEE Trans. Appl. Supercond. 15 3426-3429 (2005).
X. Peng, M.D. Sumption, M. Tomsic, E. Gregory, and E. W. Collings, “Microstructural Investigation of Internal-Tin Nb3Sn Strands”, IEEE Trans. Appl. Supercond. 15 3422-3425 (2005).
X. Wu, X. Peng, M.D. Sumption, M. Tomsic, E. Gregory, and E. W. Collings, “Ti and Sn Diffusion and its Influence on Phase Formation in Internal-tin Nb3Sn Superconductor Strands”, IEEE Trans. Appl. Supercond. 15 3399-3402 (2005).
F. Buta, M.D. Sumption, and E.W. Collings, “Flux Pinning in RHQT-Processed Nb3Al after Various Transformation Heat Treatments”, IEEE Trans. Appl. Supercond.15 3380-3384 (2005).
M. Bhatia, M.D. Sumption, and E.W. Collings, “Effect of Various Additions on Upper Critical Field and Irreversibility Field of in-situ MgB2 Superconducting Bulk Material”, IEEE Trans. Appl. Supercond. 15 3204-3206 (2005).
P.N. Barnes, G.A. Levin, C. Varanasi, and M.D. Sumption, “Low AC Loss Structures in YBCO Coated Conductors with Filamentary Current Sharing”, IEEE Trans. Appl. Supercond. 15 2827-2830 (2005).
M.D. Sumption, P.N. Barnes, and E.W. Collings, “AC Losses of Coated Conductors in Perpendicular Fields and Concepts for Twisting”, IEEE Trans. Appl. Supercond. 15 2815-2818 (2005).
M.D. Sumption, M. Bhatia, M. Rindfleisch, J. Phillips, M. Tomsic, and E. W. Collings “MgB2/Cu Racetrack Coil Winding, Insulating, and Testing”, IEEE Trans. Appl. Supercond. 15 1457-1460 (2005).
X.L. Wang, A.H. Li, S. Yu, S. Ooi, K. Hirata, C.T. Lin, E.W. Collings, M.D. Sumption, M. Bhatia, S.Y. Ding, and S.X. Dou, “Thermally Assisted Flux Flow and Individual Vortex Pinning in Bi2Sr2Ca2Cu3O10 Single Crystals Grown by the Traveling Solvent Floating Zone Technique”, J. Appl. Phys. 97 10B114 (2005).
A.H. Li, H.K. Liu, M. Ionescu, X.L. Wang, S.X. Dou, E.W. Collings, M.D. Sumption, M. Bhatia, Z.W. Lin, and J.G. Zhu, “Improvement of Critical Current Density and Thermally Assisted Individual Vortex Depinning in Pulsed-Laser-Deposited YBa2Cu3O7-d Thin Films on SrTiO3 (100) Substrate with Surface Modification by Ag Nanodots”, J. Appl. Phys. 97 10B107 (2005).
M. Bhatia, M.D. Sumption, E. W. Collings, and S. Dregia, “Increases in the Irreversibility Field and the Upper Critical Field of Bulk MgB2 by ZrB2 Addition”, Appl. Phys. Lett. 87 042505 (2005).
M.D. Sumption, M. Bhatia, F. Buta, S Bohnenstiehl, M Tomsic, M. Rindfleisch, J. Yue, J. Phillips, S. Kawabata and E.W. Collings, “Solenoidal Coils Made from Monofilamentary and Multifilamentary MgB2 Strands”, Supercond. Sci. Tech. 18 961-965 (2005).
P.N. Barnes, M.D. Sumption, and G.L. Rhoads, “Review of High Power Density Superconducting Generators: Present State and Prospects for Incorporating YBCO Windings”, Cryogenics 45 670-686 (2005).
M.D. Sumption, M. Bhatia, M. Rindfleisch, M. Tomsic, and E.W. Collings, “Transport and Magnetic Jc of MgB2 Strands and Small Helical Coils”, Appl. Phys. Let. 86 102501 (2005).
M.D. Sumption, M. Bhatia, M. Rindfleisch, M. Tomsic, S. Soltanian, S.X. Dou, and E.W. Collings, “Large Upper Critical Field and Irreversibility Field in MgB2 Wires with SiC Additions”, Appl. Phys. Let. 86 92507 (2005).
M.D. Sumption, E.W. Collings, and P. Barnes, “AC Loss in Striped (Filamentary) YBCO Coated Conductors Leading to Designs for High Frequencies and Field-Sweep Amplitudes”, Supercond. Sci. Tech. 18 122 (2005).
J. Fang, X.M. Luo, D.X. Chen, Et Al., “AC Magnetic Losses In Bi-2223/Ag Tapes with Different Aspect Ratios”, Physica C 412-414 1134-1138 ( 2004).
J. Fang, X.M. Luo, D.X. Chen, Et Al., Geometry Dependence of Magnetic and Transport AC Losses in Bi-2223/Ag Tapes with Different Aspect Ratios”, Supercond. Sci. Technol. 17 1173-1179 (2004).
T. Haugan, P.N. Barnes, R. Wheeler, F. Meisenkothen, and M. Sumption, “Addition of Nanoparticle Dispersions to Enhance Flux Pinning of the YBa2Cu3O7-X Superconductor”, Nature 430 867-870 (2004).
P.N. Barnes and M.D. Sumption, “Low Loss Striated YBa2Cu3O7-d Coated Conductor with Filamentary Current Sharing”, J. Appl. Phys. 96 6550-6556 (2004).
M. Bhatia, M.D. Sumption, M. Tomsic, and E.W. Collings, “Influence of Heat Treatment Schedules on Magnetic Jc and Phase Formation in Bulk MgB2“, Physica C, 415 158-162 (2004).
M. Bhatia, M.D. Sumption, M. Tomsic, and E.W. Collings, “Influence of Heat Treatment Schedules on the Transport Current Densities of Long and Short Segments of Superconducting MgB2 Wire”, Physica C 407 153-159 (2004).
E.W. Collings, M.D. Sumption, and T. Tajima, “Magnesium Diboride Superconducting RF Resonant Cavities for High Energy Particle Acceleration”, Supercond. Sci. Technol. 17 S595-S601 (2004).
M.D. Sumption, M. Bhatia, S .X. Dou, M. Rindfleisch, M. Tomsic, L. Arda, M. Ozdemir, Y. Hascicek and E.W. Collings, “Irreversibility Field and Flux Pinning in MgB2 with and without SiC Additions”, Supercond. Sci. Technol. 17 1180–1184 (2004)
M.D. Sumption and E.W. Collings, “Stability and Instability in High Performance (Metastable) Composite Strands During I-V Measurement”, Physica C 401 66-74 (2004).
M.D. Sumption, X. Peng, E. Lee, X. Wu, and E.W. Collings, “Analysis of Magnetization, AC Loss, and deff for Various Internal-Sn Based Nb3Sn Multifilamentary Strands with and without Subelement Splitting”, Cryogenics 44 711-725 (2004).
M.D. Sumption and E.W. Collings, “Stability and Instability in High Performance (Metastable) Composite Strands During I-V Measurement”, Physica C 401 66-74 (2004).
E. Lee, M.D. Sumption, and E.W. Collings, “Temperature and Field Dependence of the Effective Matrix Resistivity of Bi:2223/Ag Composites”, IEEE Appl. Supercond. 13 3614-3617 (2003).
X. Peng, M.D. Sumption, and E.W. Collings, “Finite Element Modeling of Hydrostatic Extrusion for Mono-Core Superconductor Billets”, IEEE Trans. Appl. Supercond. 13 3434-3437 (2003).
A. Kikuchi, Y. Iijima, K. Inoue, F. Buta, M.D. Sumption, and E.W. Collings, “Nb3Sn Wires Synthesized by Rapid-Heating/Quenching Process of Rod-In-Tube Wire Precursors”, IEEE Trans. Appl. Supercond. 13 3430-3433 (2003).
E.W. Collings, E. Lee, M.D. Sumption, M. Tomsic, “Continuous- and Batch-Processed MgB2/Fe Strands - Transport and Magnetic Properties”, Physica C 386 555-559 (2003).
M.D. Sumption and E.W. Collings, “Stability and Flux Jumping of Internal-Sn, Nb3Sn Conductors (and a Model System, MgB2)”, IEEE Trans. Appl. Supercond. 13 3394-3397 (2003).
M.D. Sumption, X. Peng, E. Lee, F. Buta, E.W. Collings, and M. Tomsic, “Fabrication and Properties of PIT Nb-Al and Nb-Sn Based Superconductors”, IEEE Trans. Appl. Supercond. 13 3486-3489 (2003).
M.D. Sumption, F. Buta, M. Tomsic, A. Austen, E. Gregory, M. Rudziak, T. Wong, L. Motowidlo, Y. Hascicek, R. M. Scanlan, H. Higley, and E.W. Collings, “Nb3Al Strand Processing, Transport Properties, and Cabling”, IEEE Trans. Appl. Supercond. 13 3466-3469 (2003).
F. Buta, M. D. Sumption, and E. W. Collings, “Influence of Transformation Heat Treatment on Microstructure and Defects in RHQT-Processed Nb3Al”, IEEE Trans. Appl. Supercond. 13 3458-3461 (2003).
F. Buta, M. D. Sumption, and E. W. Collings, “Phase Stability at High Temperatures in the Nb-Al System”, IEEE Trans. Appl. Supercond. 13 3462-3465 (2003).
S. Soltanian, X.L. Wang, A.H. Li, E.W. Collings, M.D. Sumption, E. Lee, H.K. Liu, and S.X. Dou , “Fabrication and Critical Current Density in 16-Filament Stainless Steel/Fe/MgB2 Square Wire”, Solid State Commun. 124 59-62 (2002).
E.W. Collings, E. Lee, X.L. Wang, and M.D. Sumption, “Real and Apparent Loss Suppression in MgB2 Superconducting Composites”, Physica C 382 98-103 (2002).
M.D Sumption, E.W. Collings, and E. Lee, “Reduction and Elimination of External-Field AC Loss in MgB2/Fe Wire by in-situ Magnetic Shielding”, Physica C 378-381 894-898 (2002).
E.W. Collings, E. Lee, M.D. Sumption, and M. Tomsic, “Transport and Magnetic Properties of Continuously Processed MgB2“, Rare Metal Mat. Eng. 31 406-409 (2002).
H. Harada, T. Nakano, M. Tsuda, T. Hamajima, F. Buta, E. Lee, M.D. Sumption, E.W. Collings, K. Tagawa, H. Moriai, T. Takeuchi, H. Wada, and K. Watanabe, “Influence of Rapid Heating Condition on Superconducting Properties in Transformed Jelly-Roll Nb3Al Multifilamentary Wire”, IEEE Trans. Appl. Supercond. 12 1033-1036 (2002).
M.D. Sumption, E.L. Coleman, C.B. Cobb, P.N. Barnes, T.J. Haugan, J. Tolliver, C.E. Oberly, and E.W. Collings, “Hysteretic Loss vs. Filament Width in Thin YBCO Films Near the Penetration Field”, IEEE Trans. Appl. Supercond. 13 3553-3556 (2003).
T. Haugan, P.N. Barnes, I. Maartense, C.B. Cobb, E.J. Lee, and M.D. Sumption, “Island Growth Of Y2BaCuO5 Nanoparticles in (211(~1.5 nm)/123(~10nm))Xn Composite Multilayer Structures to Enhance Flux Pinning of YBa2Cu3O7-d Films”, J. Mat. Res. 18 2618-2623 (2003).
C.B. Cobb, P.N. Barnes, T.J. Haugan, J. Tolliver, E. Lee, M.D. Sumption, E.W. Collings, and C.E. Oberly, “Hysteretic Loss Reduction in Striated YBCO”, Physica C 382 52-56 (2002).
M.D. Sumption, E.W. Collings, R.M. Scanlan, S.W. Kim, M. Wake, T. Shintomi, A. Nijhuis, and H.H.J. Ten Kate, “AC Loss in Cored Stabrite Cables in Response to External Compaction and Variation of Core Thickness and Width”, Cryogenics 41 733-744 (2001).
M.D. Sumption, R.M. Scanlan, and E.W. Collings, “Coupling Loss and Contact Resistance in Cored Stabrite Cables -- Influences of Compaction and Variation of Core Width”, IEEE Trans. Appl. Supercond. 11 2571-2574 (2001).
S. Soltanian, X.L. Wang, I. Kusevic, E. Babic, A.H. Li, M.J. Qin, J. Horvat, H.K. Liu, E.W. Collings, E. Lee, M.D. Sumption, and S.X. Dou, “High Transport Critical Current Density above 30 K in Pure Fe-Clad MgB2 Tape”, Physica C 361 84-90 (2001).
M.D. Sumption, E.W. Collings, R.M. Scanlan, S.W. Kim, M. Wake, T. Shintomi, A. Nijhuis, and H.H.J. Ten Kate, “AC Loss and Interstrand Contact Resistance in Bare and Coated NbTi/Cu Rutherford Cables with Cores”, Supercond. Sci. Tech. 14 888-897 (2001).
E.W. Collings and M.D. Sumption, “Static and Dynamic Parasitic Magnetizations and their Control in Superconducting Accelerator Dipoles”, Physica C 354 60-65 (2001).
E.W. Collings and M.D. Sumption, “Transverse Resistivities an Untwisted HTSC Tapes at 4.2, 30, and 60 K”, Physica C 357-360 1153-1159 (2001).
M.D. Sumption, E. Lee, and E.W. Collings, “Analysis of Eddy Current AC Loss for Untwisted, Multifilamentary Superconducting Composites with Various Aspect Ratios”, IEEE Trans. Appl. Supercond. 11 2963-2966 (2001).
S.X. Dou, X.L. Wang, J. Horvat, D. Milliken, A.H. Li, K. Konstinov, E.W. Collings, M.D Sumption, and H.K. Liu, “Flux Jumping and a Bulk-To-Granular Transition in the Magnetization of a Compacted and Sintered MgB2 Superconductor”, Physica C 361 79-83 (2001).
E.W. Collings, M.D. Sumption, and E. Lee, “Magnetization as a Critical Defining Parameter for Strand in Precision Dipole Applications -- Implications for Field Error and F-J Stability”, IEEE Trans. Appl. Supercond. 11 2567-2570 (2001).
F. Buta, M.D. Sumption, and E.W. Collings, “Studies for Processing Nb3Al Using a Rapid Ohmic-Heating and Quenching Method”, IEEE Trans. Appl. Supercond. 11 3980-3983 (2001).
N. Harada, T. Nakano, M. Tsuda, T. Hamajima, F. Buta, E. Lee, M.D. Sumption, E.W. Collings, K. Tagawa, H. Moriai, T. Takeuchi, H. Wada, and K. Watanabe, “Superconducting Properties and Rapid Heating Condition in Transformed Jelly-Roll Nb3al Multifilamentary Wires as a Function of Maximum Ohmic-Heating Temperature”, IEEE Trans. Appl. Supercond. 11 3611-3614 (2001).
M.D. Sumption, E. Lee, S.X. Dou, and E.W. Collings, “Extraction of Matrix Resistivity from Short Samples of Superconducting Multifilamentary Composite Tapes: Influence of Strand Twist Pitch and Internal Structure”, Physica C 335 164-169 (2000).
M.D. Sumption, R.M. Scanlan, A. Nijhuis, and E.W. Collings, “AC Loss and Contact Resistance in Copper Stabilized Nb3Al Rutherford Cables with and without a Stainless Steel Core”, IEEE Trans Appl. Supercond. 10 1196-1199 (2000).
M.D. Sumption, E.W. Collings, A. Nijhuis, and R.M. Scanlan, “Coupling Current Control in Stabrite-Coated NbTi Rutherford Cables by Varying the Width of a Stainless Steel Core”, Adv. Cryo. Eng. 46 1043-1049 (2000).
M.D. Sumption, E. Lee, and E.W. Collings, “Influence of Filamentary and Strand Aspect Ratios on AC Loss in Short, Untwisted Samples of HTSC and LTSC Superconducting Multifilamentary Composites”, Physica C 337 187-194 (2000).
E.W. Collings, M.D. Sumption, R.M. Scanlan, D.R. Dietderich, L.R. Motowidlo, R.S. Sokolowski, Y. Aoki, and T. Hasegawa, “Bi:2212/Ag-Based Rutherford Cables: Production, Processing, and Properties”, Supercond. Sci. Technol. 12 87-96 (1999).
M.D. Sumption, E.W. Collings, R.M. Scanlan, A. Nijhuis, and H.H.J. Tenkate, “Core Suppressed AC Loss and Strand-Moderated Contact Resistance in a Nb3Sn Rutherford Cable”, Cryogenics 39 1-12 (1999).
M.D. Sumption, E.W. Collings, and E. Gregory, “Low Field Flux Jumping in High Performance Multifilamentary Nb3Al and Nb3Sn Composite Strands”, IEEE Trans. Appl. Supercond. 9 1455-1458 (1999).
E.W. Collings, M.D. Sumption, R.M. Scanlan, D.R. Dietderich, and L.R. Motowidlo, “Low Coupling Loss Core-Strengthened Bi:2212/Ag Rutherford Cables”, IEEE Trans. Appl. Supercond. 9 758-761 (1999).
E. Gregory, M. Tomsic, F. Buta, M.D. Sumption, and E.W. Collings, “Process Development and Microstructures of Nb3Al Precursor Strand for Reel-To-Reel Production”, IEEE Trans. Appl. Supercond. 9 2692-2695 (1999).
F. Buta, M.D. Sumption, E.W. Collings, N, Harada, E. Gregory, and M. Tomsic, “Short Sample Quenching of Nb3al Precursor Strand in Support of Reel-To-Reel Process Development”, IEEE Trans. Appl. Supercond 9 1433-1436 (1999).
M.D. Sumption, E.W. Collings, R.M. Scanlan, A. Nijhuis, H.H.J. Ten Kate, S.W. Kim, M. Wake, and T. Shintomi, “Influence of Strand Surface Condition on Interstrand Contact Resistance and Coupling Loss in NbTi-Wound Rutherford Cables”, Cryogenics 39 197-208 (1999).
M.D. Sumption and S. Takacs, “Flux Pinning in the Weak Layers of Superconducting Heterogeneous Structures”, Physica C 316 129-151 (1999).
M.D. Sumption, R.M. Scanlan, and E.W. Collings, “AC Loss Properties of Some Bi:2212/Ag Rutherford Cables and a Comparison of Those with Cables Wound with NbTi and Nb3Sn”, Cryogenics 38 1225-1232 (1998).
M.D. Sumption, S. Takacs, and E.W. Collings, “Modelling of M-H Loop Anomalies in Synergistically Pinned, Heterogeneous, Composite Superconductors”, Physica C 306 300-308 (1998).
M.D. Sumption, R.M. Scanlan, and E.W. Collings, “Coupling Current Control in Rutherford Cables Wound With NbTi, Nb3Sn, and Bi:2212/Ag”, Physica C 310 291-295 (1998).
M.D. Sumption, L.R. Motowidlo, and E.W. Collings, “Determination of the True (or Potential) Transport-Jc of a Multifilamentary Bi-HTSC/Ag Strand in the Presence of Bridging and Generalized Sausaging”, Physica C 291 267-273 (1997).
M.D. Sumption, E.W. Collings, E. Gulko, T. Pyon, and E. Gregory, “Analysis of Optically and Magnetically Determined Bridging in Internal-Tin Process Nb3Sn Strands, IEEE Trans. Appl. Supercond. 7 1368-1371 (1997).
M.D. Sumption, and E.W. Collings, “Effect Current Strengths in NbTi Multifilamentary Samples with and without Nb Barriers and Processed Under Various Conditions”, IEEE Trans. Appl. Supercond. 7 1117-1121 (1997).
E.W. Collings, M.D. Sumption, S.W. Kim, M. Wake, T. Shintomi, A. Nijhuis, H.H.J. Ten Kate, and R.M. Scanlan, “Suppression and Control of Coupling Currents in Stabrite-Coated Rutherford Cable With Cores of Various Materials and Thicknesses”, IEEE Trans. Appl. Supercond. 7 962-966 (1997).
E.W. Collings, M.D. Sumption, K. Itoh, H. Wada, and K. Tachikawa”, Second VAMAS AC Loss Measurement Intercomparison: Magnetization Measurement of Low-Frequency (Hysteretic) AC Loss in NbTi Multifilamentary Strands”, Cryogenics 37 49-60 (1997).
M.D. Sumption and E.W. Collings, “Anomalous Magnetic Properties and Proximity Effect Coupling in VAMAS Strands, Cryogenics 37 165-170 (1997).
M.D. Sumption and E.W. Collings, ”A Model for Bridging and Coupling in Superconductors”, Physica C 261 245-258 (1996).
L.R. Motowidlo, G. Galinsky, G. Ozeryansky, W. Zhang, E.E. Hellstrom, M.D. Sumption, and E.W. Collings, “The Influence of Filament Size and Atmosphere on the Microstructure and Jc of Round Filament Bi2Sr2Ca1Cu2Ox Wires”, IEEE Trans. Applied Supercond. 5 1162 (1995).
E.W. Collings and M.D. Sumption, “Stability and AC Losses in HTSC/Ag Multifilamentary Strands”, Applied Superconductivity 5 551-557 (1995).
E. Gregory, E.A. Gulko, T. Pyun, M.D. Sumption, and E.W. Collings, “Dual Barrier for the Suppression of Residual Resistance Degradation in Chrome-Plated Niobium-Tin Strands”, IEEE Trans. Appl. Supercond. 5 1921-1924 (1995).
E.W. Collings, M.D. Sumption, K. Itoh, H. Wada, and K. Tachikawa, “Report on the Second VAMAS AC Loss Round Robin -- Magnetization Measurement of Low-Frequency Hysteretic Loss”, IEEE Trans. Appl. Supercond. 5 540-544 (1995).
M.D. Sumption and E.W. Collings, “A Comparison of AC Loss, Magnetization, Hr, and U0 for Bi:2212 Wires, Crystals, and Melt Grown Samples, Applied Superconductivity 3, 521-533 (1995).
E.W. Collings and M.D. Sumption, “Materials Selection for Ferromagnetic Compensation in Accelerator Magnets”, IEEE Trans. Appl. Supercond. 5 408-411 (1995).
M.D. Sumption, H.H.J. Tenkate, R.M. Scanlan, and E.W. Collings, “Contact Resistance and Cable Loss Measurement of Coated Strands and the Cables Wound From Them”, IEEE Trans. Appl. Supercond. 5 692-696 (1995).
M.D. Sumption and E.W. Collings, “Chromium Diffusion into Plated NbSn Strands Deduced From Electrical Resistivity Measurement”, IEEE Trans. Appl. Supercond. 5 1925-1928 (1995).
M.D. Sumption, “Calculation of the Magnetization of Anisotropic Superconductors with Cylindrical Geometry in Transverse Fields”, Applied Superconductivity 2 41-46 (1994).
M.D. Sumption and E.W. Collings, “Creep in Superconductive Composites with Anisotropic Pinning Potentials”, J. Appl. Phys., 76 4766 (1994).
M.D. Sumption and E.W. Collings, “Influence of Ni Additions on the Low Temperature Magnetic Properties of A Cu-1%Ni Alloy”, J. Appl. Phys. 76 7461 (1994).
M.D. Sumption and E.W. Collings, “Influence of Twist-Pitch and Sample Length on Proximity Effect Coupling in Multifilamentary Composites Described in Terms of a Field-Independent, Two-Current-Region Model”, Cryogenics 34, 491-505 (1994).
M.D. Sumption and E.W. Collings, “Innovative Strand Design for Accelerator Magnets”, Int. J. Mod. Phys. A (Proc. Suppl.) 2B, 662-664 (1993).
M.D. Sumption, K.R. Marken, Jr., and E.W. Collings, “Enhanced Static Magnetization and Creep in SCC-Type Strands via Cable and Twist Pitch Assisted Proximity Effects”, IEEE Trans. Appl. Supercond. 3 751-756, (1993).
M.D. Sumption, D.S. Pyun, and E.W. Collings, “Transverse and Longitudinal Resistivities in NbTi Multifilamentary Strands with Cu and CuMn Matrices”, IEEE Trans. Appl. Supercond. 3 859-862 (1993).
E.W. Collings, M.D. Sumption, and W.J. Carr, Jr., “Hysteretic Method of Lower Critical Field Determination in High Tc Superconductors”, Supercond. Sci. Technol. 5 S248-255 (1992).
E.W. Collings and M.D. Sumption, “AC Loss and Transverse Resistivity in Multifilamentary Strands with Matrices of Cu and CuMn”, Cryogenics 32 585-588 (1992).
E.W. Collings and M.D. Sumption, “Advanced Strand Design for Precision DC-Field and Ramp-Field Magnets, IEEE Trans. Magn. 28, 156-159 (1992).
E.W. Collings, K.R. Marken, Jr., M.D. Sumption, G. Iwaki, and S. Sakai, “Design, Fabrication, and Properties of Magnetically Compensated SSC Strands, IEEE Trans. Magn. 27, 1787-1790 (1991).
K.R. Marken, A.J. Markworth, M.D. Sumption, E.W. Collings, and R.M. Scanlan, “Eddy-Current Effects in Twisted and Wound SSC Strands, IEEE Trans. Magn. 27, 1791-1795 (1991).
M.D. Sumption, K.R. Marken, Jr., and E.W. Collings, “Position and Amplitude of Proximity Effect Peaks in the Magnetization Curves of NbTi/Cu and NbTi/CuMn Multifilamentary Strands, IEEE Trans. Magn. 27, 1129-1132 (1991).
M.D. Sumption, K.R. Marken, Jr., and E.W. Collings, “Hysteretic Surface Effects in Multifilamentary NbTi Wires Exposed to Transverse Applied Fields”, IEEE Trans. Appl. Magn. 27, 2166-2169 (1991).
E.W. Collings, K.R. Marken, Jr., and M.D. Sumption, “Interfilament and Intrafilament Magnetizations in Fine-Filament Composite Strands for Precision-Dipole Magnet Applications”, Cryogenics 30, 48-55, (1990)

R. Morrow, M. A. Susner, M. D. Sumption, and P. M. Woodward, “Magnetic structure of the quasi-one-dimensional La3OsO7 as determined by neutron powder diffraction”, Phys. Rev. B 92, 134402 (2015).
Y.Yang, G.Li, M.Susner, M.D.Sumption, M.Rindfleisch, M.Tomsic, E.W.Collings, “Influence of twisting and bending on the Jc and n-value of multifilamentary MgB2 strands”, Physica C (2015)118–123.
G.Z. Li, M.A. Susner, S.D. Bohnenstieh, M.D. Sumption, E.W. Collings, “Microstructures and superconducting properties of high performance MgB2 thin films deposited from a high-purity, dense Mg–B target”, Applied Surface Science 357 (2015) 452–458.
G. Li, M.D. Sumption, and E.W. Collings, “Kinetic Analysis of MgB₂ Layer Formation in Advanced Internal Magnesium Infiltration (AIMI) Processed MgB₂ Wires”, Acta Materialia, 96 (20150901): 66-71
E. W. Collings, M. D. Sumption, M. Majoros, X. Wang, and D. R. Dietderich, “Effects of Core Type, Placement, and Width, on the Estimated Interstrand Coupling Properties of QXF-Type Nb3Sn Rutherford Cables”, IEEE Trans. Appl. Supercon. 25 (2015) 4802805, DOI: 10.1109/TASC.2015.2390628
M. Majoros, M. Sumption, E.W. Collings, and N. Long, “Inter-strand Current Sharing and AC Loss Measurements in Superconducting YBCO Roebel Cables" Superconductor Science and Technology, v28 n5 (20150501): 055010
C. S. Myers, H. Miao, Y. Huang, M. D. Sumption, and E. W. Collings, “Reduced Magnetization and Loss In Ag-Mg Sheathed Bi2212 wires: Systematics With Sample Twist Pitch and Length”, IEEE Trans. Appl. Supercon. 25 (2015) 8201604, DOI: 10.1109/TASC.2014.2372614
N. P. Bansal , J. C. Goldsby, R. B. Rogers, M. A. Susner, M. D. Sumption”, Chemical Synthesis of Superconducting MgB2 Nanopowder”, Journal of Alloys and Compounds 622 (2015) 986–988.
X. Wang, G. Ambrosio, G. Chlachidze, E. W. Collings, D. R. Dietderich, J. DiMarco, H. Felice, A. K. Ghosh, A. Godeke, S. A. Gourlay, M. Marchevsky, S. O. Prestemon, G. Sabbi,M. D. Sumption, G. V. Velev, X. Xu, and A. V. Zlobin, “Validation of Finite-Element Models of Persistent-Current Effects in Nb3Sn Accelerator Magnets”, IEEE Trans. Appl. Supercond. 25, (2015) 4003006.
X. Xu, M. Majoros, M. D. Sumption, and E. W. Collings, “Persistent-Current Magnetization of Nb3Sn Strands: Influence of Applied Field Angle and Transport Current”, IEEE Trans. Appl. Supercond. 25 (2015) 8200704.
X. Xu , M. D. Sumption, and X. Peng, “Internally Oxidized Nb3Sn Strands with Fine Grain Size and High Critical Current Density”, Adv. Mater. 2015, 27, 1346–1350.

N. W. Khun, G. S. Frankel, and M. Sumption, “Effects of Normal Load, Sliding Speed, and Surface Roughness on Tribological Properties of Niobium under Dry and Wet Conditions”, Tribology Transactions, 57: 944-954, 2014
S.D. Bohnenstiehl, M.A. Susner, S.A. Dregia, M.D. Sumption, J. Donovan, E.W. Collings”, Experimental Determination of the Peritectic Transition Temperature of MgB2 in the Mg–B Phase Diagram”, Thermochimica Acta 576 (2014) 27– 35.
M Majoros, M D Sumption, E W Collings and D C van der Laan, “Magnetization losses in superconducting YBCO conductor-on-round-core (CORC) cables”, Supercond. Sci. Technol. 27 (2014) 125008 (12pp); doi:10.1088/0953-2048/27/12/125008.
X Xu, M D Sumption and E W Collings, “Influence of heat treatment temperature and Ti doping on low-field flux jumping and stability in (Nb-Ta)3Sn strands”, Supercond. Sci. Technol. 27 (2014) 095009 (10pp); doi:10.1088/0953-2048/27/9/095009.
C Zhou, P Gao, H J G Krooshoop, M Dhallé, M D Sumption, M Rindfleisch, M Tomsic, M Kulich, C Senatore and A Nijhuis, “Intrawire resistance, AC Loss and Strain Dependence of Critical Current in MgB2 Wires with and without Cold High-Pressure Densification”, Supercond. Sci. Technol. 27 (2014) 075002 (5pp) doi:10.1088/0953-2048/27/7/075002.
M A Susner, M D Sumption, A Takase and E W Collings, “Evidence for Zr Site-Substitution for Mg in PLD-deposited MgB2 Thin Films”, Supercond. Sci. Technol. 27 (2014) 075009 (7pp); doi:10.1088/0953-2048/27/7/075009.
M.A.Susner, S.D.Carnevale, T.F.Kent, L.M.Gerber, P.J.Phillips, M.D. Sumption, R.C.Myers, “Catalyst-free ZnO Nanowires on Silicon by Pulsed laser Deposition with Tunable Density and Aspect Ratio”, Physica E 62 (2014) 95–103.
T. L. Meyer, M. Dixit, R. E. A. Williams, M. A. Susner, H. L. Fraser, D. W. McComb, M. D. Sumption, T. R. Lemberger, and P. M. Woodward, “Cation non-stoichiometry in Pulsed Laser Deposited Sr2+yFe1+xMo1-xO6 Epitaxial Films”, J. Appl. Phys. 116, 013905 (2014); doi: 10.1063/1.4885450
M. Majoros, M. D. Sumption, E. W. Collings, and N. J. Long, “Stability, Inter-Strand Contact Resistance, and AC Losses in YBCO Roebel Cables, IEEE Trans. Appl. Supercond. 24 (2014) 6600505.
G. Li, J. B. Zwayer, C. J. Kovacs, M. A. Susner, M. D. Sumption, M. A. Rindfleisch, C. J. Thong, M. Tomsic, and E. W. Collings, “Transport Critical Current Densities and n-Values of Multifilamentary MgB2 Wires at Various Temperatures and Magnetic Fields”, IEEE Trans. Appl. Supercond. 24 (2014) 6200105.
E. W. Collings, M. A. Susner, M.D. Sumption, and D. R. Dietderich, “Extracted Strand Magnetizations of an HQ Type Nb3Sn Rutherford Cable and Estimation of Transport Corrections at Operating and Injection Fields”, IEEE Trans. Appl. Supercond. 24 (2014) 4802605.
X. Xu, E. Collings, M. Sumption, C. Kovacs, and X. Peng, “The Effects of Ti Addition and High Cu/Sn Ratio on Tube Type (Nb, Ta)3Sn Strands, and a New Type of Strand Designed to Reduce Unreacted Nb Ratio”, IEEE Trans. Appl. Supercond. 24 (2014) 6000904
M. A. Susner, S. D. Bohnenstiehl, S. A. Dregia, M. D. Sumption, Y. Yang, J. J. Donovan, and E. W. Collings, “Homogeneous carbon doping of magnesium diboride by high-temperature, high-pressure synthesis”, Applied Physics Letters 104, 162603 (2014); doi: 10.1063/1.4871578
X. Xu, M. Sumption, X. Peng, and E. W. Collings, “Refinement of Nb3Sn grain size by the generation of ZrO2 precipitates in Nb3Sn wires”, Applied Physics Letters 104, 082602 (2014); doi: 10.1063/1.4866865
G. Z. Li, M. D. Sumption, M. A. Rindfleisch, C. J. Thong, M. J. Tomsic, and E. W. Collings, “Enhanced higher temperature (20–30 K) transport properties and irreversibility field in nano-Dy2O3 doped advanced internal Mg infiltration processed MgB2 composites”, Applied Physics Letters 105, 112603 (2014); doi: 10.1063/1.4896259
N. W. Khun, M. Sumption, G. S. Frankel, “Smoothening of niobium by electropolishing”, J Appl Electrochem (2013) 43:829–838.
M.A. Susner, M.D. Sumption, M.A. Rindfleisch, E.W. Collings, “Critical current densities of doped MgB2 strands in low and high applied field ranges: The Jc(B) crossover effect”, Physica C 490 (2013) 20–25.
F.F. Yuan, Y. Ding, Y. Sun, J.C. Zhuang, W. Zhou, G.Z. Li, M. Sumption, X.W. Li, Z.X. Shi, “Effects of oxide precursors on superconducting properties of polycrystalline SmFeAsO1-xFx“, Physica C 495 (2013) 198–201.
G Z Li, M D Sumption, J B Zwayer, M A Susner, M A Rindfleisch, C J Thong, M J Tomsic and E W Collings, “Effects of carbon concentration and filament number on second generation internal Mg diffusion MgB2 strands”, Supercond. Sci. Technol. 26 (2013) 095007.
X Xu, M D Sumption and E W Collings", A Model for Phase Evolution and Volume Expansion in Tube Type Nb3Sn Conductors”, Supercond. Sci. Technol. 26 (2013) 125006
X Xu, M D Sumption, S Bhartiya, X Peng, and E W Collings, "Critical current densities and microstructures in Rod-in-Tube and Tube Type Nb3Sn strands – Present status and prospects for improvement”, Supercond. Sci. Technol. 26 (2013) 075015
C. Zhou, W. Offringa, A. Bergen, W.A..J. Wessel, H. J. G. Krooshoop, M. Dhall´e, M.D. Sumption, E.W. Collings, M. Rindfleisch, M. Tomsic, H.H. J. ten Kate and A. Nijhuis, “Intra-Wire Resistance and AC Loss in Multi-Filamentary MgB2 Wires”, Supercond. Sci. Technol. 26 (2013) 025002.
G. Z. Li, K. M. Reddy, J. B. Zwayer, M. A. Kuldell, M. A. Susner, Y. Yang, M. D. Sumption, J. J. Yue, M. A. Rindfleisch, M. J. Tomsic, C. J. Thong, and E. W. Collings, “Critical Current Density and Current Transfer Length of Multifilamentary MgB2 Strands of Various Design”, IEEE Trans. Appl. Supercond. 23 (2013) 6200204.
C. S. Myers, M. A. Susner, L. Motowidlo, J. Distin, M. D. Sumption, and E. W. Collings, “Specific Heats of Composite Bi2212, Nb3Sn, and MgB2 Wire Conductors”, IEEE Trans. Appl. Supercond. 23 (2013). 8800204
M. Kanuchova, M. Majoros, J. Kanuch, Y. Ding, M. A. Susner, M. D. Sumption, and E. W. Collings, “LiFeAs Pnictide Superconductor—A Simple Electrochemical Method of Preparation”, IEEE Trans. Appl. Supercond, 23 (2013) 7300204.
E. W. Collings, M. D. Sumption, M. A. Susner, D. R. Dietderich, E. Kroopshoop, and A. Nijhuis, “Coupling- and Persistent-Current Magnetizations of Nb3Sn Rutherford Cables With Cores of Stainless Steel and Woven Glass-Fiber Tape Measured by Pick-Up Coil Magnetometry”, IEEE Trans. Appl. Supercond, 23 (2013) 4702305.
J. P. Murphy, M.J. Mullins, P.N. Barnes, T.J. Haugan, G.A. Levin, M.Majoros, M.D. Sumption, E. W. Collings, M. Polak, and P. Mozola, “ Experiment Setup for Calorimetric Measurements of Losses in HTS Coils Due to AC Current and External Magnetic Fields”, IEEE Trans. Appl. Supercond, 23 (2013) 4701505.
H. S. Kim, M. D. Sumption, H. Lim, and E. W. Collings, “Evaluation of Mechanical Properties of Tubular Materials with Hydraulic Bulge Test for Superconducting Radio Frequency (SRF) Cavities”, IEEE Trans. Appl. Supercond, 23 (2013) 3500604.
A. Chandra, M. Sumption, G.S. Frankel, “On the mechanism of niobium electropolishing, Journal of the Electrochemical Society, v159 n11 (2012 12 01): C485-C491.
M.A Susner, T.W. Daniels, M.D. Sumption, M.A. Rindfleisch, C.J. Thong and E.W. Collings, Drawing Induced Texture and the Evolution of Superconductive Properties with Heat Treatment Time in Powder-in-tube in-situ Processed MgB2 Strands”, Supercond. Sci. Technol. 25 (2012) 065002 (13pp).
G Z Li, Y Yang, M A Susner, M D Sumption and E W Collings, “Critical Current Densities and n-values of MgB2 Strands over a Wide Range of Temperatures and Fields”, Supercond. Sci. Technol. 25 (2012) 025001 (10pp).
A.J. Hauser, J. R. Soliz, M. Dixit, R.E.A. Williams, M. A. Susner, B. Peters, L.M. Mier, T. L. Gustafson, M.D. Sumption, H.L. Fraser, P.M. Woodward, and F.Y. Yang, “Fully Ordered Sr2CrReO6 Epitaxial Films: A High-temperature Ferrimagnetic Semiconductor, Phys. Rev. B 85, 161201(R) (2012).
E. W. Collings, M.D. Sumption, M. A. Susner, D. R. Dietderich, E. Krooshoop and A. Nijhuis, “Interstrand Contact Resistance and Magnetization of Nb3Sn Rutherford Cables with Cores of Different Materials and Widths”, IEEE Trans. Appl. Supercond. 22 (2012).
Y. Yang, M.A. Susner, M.D. Sumption, M. Rindfleisch, M. Tomsic, and E.W. Collings, “Influence of Strand Design, Boron Type, and Carbon Doping Method on the Transport Properties of Powder-in-Tube MgB2−XCX Strands”, IEEE Trans. Appl. Supercond. 22 (2012) 6200110.
M.D. Sumption, S. Bhartiya, C. Kovacks, X. Peng, E. Gregory, M.J. Tomsic, E.W. Collings, “Critical Current Density and Stability of Tube Type Nb3Sn Conductors”, Cryogenics 52 (2012) 91–99.
M.A. Susner, Y. Yang, M.D. Sumption, E.W. Collings, M.A. Rindfleisch, M.J. Tomsic and J.V. Marzik, “RAPID COMMUNICATION: Enhanced Critical Fields and Superconducting Properties of Pre-doped B Powder-Type MgB2 Strands”, Supercond. Sci. Technol. 24 (2011) 012001 (5pp).
Y. Ding, Y. Sun, J.C. Zhuang, L.J. Cui, Z.X. Shi, M.D. Sumption, M. Majoros,M.A. Susner, C.J. Kovacs, G.Z. Li, E.W.Collings and Z.A. Ren, “Density Effect on Critical Current Density and Flux Pinning Properties of Polycrystalline SmFeAsO1−xFx Superconductor”, Supercond. Sci. Technol. 24 (2011) 125012 (7pp).
Z.X. Shi, M.A. Susner, M.D. Sumption, E.W. Collings, X. Peng, M. Rindfleisch and M.J. Tomsic, “Doping effect and flux pinning mechanism of nano-SiC additions in MgB2 strands” Supercond. Sci. Technol. 24 (2011) 065015 (7pp).
S.D. Bohnenstiehl, M.A. Susner, Y. Yang, E.W. Collings, M.D. Sumption, M.A. Rindfleisch, R. Boone, “Carbon Doping of MgB2 by Toluene and Malic-Acid-in-Toluene”, Physica C 471 (2011) 108–111.
M. Majoros, M. D. Sumption, and E. W. Collings, “Stability and Normal Zone Propagation in a 50 Tesla Solenoid Wound of YBCO Coated Conductor Tape – FEM Modeling”, IEEE Trans. Appl. Supercond. 99 (2011) 1.
M. Majoros, M. D. Sumption, M. A. Susner, E. W. Collings, J. Souc, F. Gomory, M. Vojenciak, L. M. Fisher, A. V. Kalinov, and I. F. Voloshin, “AC Magnetization Loss of a YBCO Coated Conductor Measured Using Three Different Techniques”, IEEE Trans. Appl. Supercond. 21 (2011) 3293-3296.
M. Majoros, M. Kanuchova, M. A. Susner, M. D. Sumption, C. S. Myers, S. D. Bohnenstiehl, and E. W. Collings, “Effects of Heat Treatments on the Properties of SmFeAsO1-xFx Oxypnictide Bulks Prepared via a Single-Step Route”, IEEE Trans. Appl. Supercond. 21 (2011) 2853-2857.
C. S. Myers, M. A. Susner, L. Motowidlo, J. Distin, M. D. Sumption, and E. W. Collings, “Transport, Magnetic, and SEM Characterization of a Novel Design Bi-2212 Strand”, IEEE Trans. Appl. Supercond. 21 (2011) 2804-2807.
X. Peng, E. Gregory, M. Tomsic, M. D. Sumption, A. Ghosh, X. F. Lu, N. Cheggour, T. C. Stauffer, L. F. Goodrich, and J. D. Splett, “Strain and Magnetization Properties of High Subelement Count Tube-Type Nb3Sn Strands”, IEEE Trans. Appl. Supercond. 21 (2011) 2559-2562.
M. G. T. Mentink, A. Anders, M. M. J. Dhalle, D. R. Dietderich, A. Godeke, W. Goldacker, F. Hellman, H. H. J. ten Kate, D. Putnam, J. L. Slack, M. D. Sumption, and M. A. Susner, “Analysis of Bulk and Thin Film Model Samples Intended for Investigating the Strain Sensitivity of Niobium-Tin”, IEEE Trans. Appl. Supercond. 21 (2011) 2550-2553.
E. W. Collings, M. D. Sumption, M. A. Susner, D. R. Dietderich, and A. Nijhuis, “Coupling Loss, Interstrand Contact Resistance, and Magnetization of Nb3Sn Rutherford Cables With Cores of MgO Tape and S-Glass Ribbon”, IEEE Trans. Appl. Supercond. 21 (2011) 2367-2371.
M. Majoros, M. D. Sumption, E.W. Collings, and M. Tomsic, “Design of a Nb3Sn-Based Short Period Model Superconducting Helical Undulator”, IEEE Trans. Appl. Supercond. 21 (2011) 1713-1716.
L.S. Lakshmi, M.P. Staines, R.A. Badcock, N.J. Long, M. Majoros, E.W. Collings and M.D. Sumption, “Frequency Dependence of Magnetic AC Loss in a Roebel Cable Made of YBCO on a Ni–W substrate”, Supercond. Sci. and Tech. 23 (2010) 085009.
M.D. Sumption, M. Majoros, M. Susner, D. Lyons, X .Peng, C.F. Clark, W.N. Lawless and E.W. Collings, “Thermal Diffusion and Quench Propagation in YBCO Pancake Coils Wound with ZnO and Mylar Insulations”, Supercond. Sci. and Tech. 23 (2010) 075004.
Z.X. Shi, M.A. Susner, M. Majoros, M.D. Sumption, X. Peng, M. Rindfleisch, M.J. Tomsic and E.W. Collings, “Anisotropic Connectivity and its Influence on Critical Current Densities, Irreversibility Fields, and Flux Creep in in-situ Processed MgB2 Strands, “Supercond. Sci. Tech. 23 (2010)-045018.
E.W. Collings, M.D. Sumption, M.A. Susner, E. Barzi, D. Turrioni, R. Yamada, A.V. Zlobin, and A. Nijhuis, “Coupling- and Persistent-Current Magnetizations of Nb3Sn Rutherford Cables”, IEEE Trans. Appl. Supercond. 20, (2010) 1387.
M. Majoros, M. D. Sumption, M. A. Susner, S. Bhartiya, M. Mahmud, E. W. Collings, M. Tomsic, M. Rindfleisch, J. Phillips, D. Lyons, and J. Yue, “A Nb3Sn-Based, Model Superconducting Helical Undulator Fabricated Using a Wind and React Process”, IEEE Trans. Appl. Supercond. 20, (2010) 270.

M. A. Susner, M. Bhatia, M. D. Sumption, and E. W. Collings, “Electrical resistivity, Debye temperature, and connectivity in heavily doped bulk MgB2 superconductors”, . Appl. Phys. 105, 103916 (2009).
Y.S. Hascicek, Y.Akin, T.W. Baldwin, M.M. Rindfleisch, J. Yue, M.D. Sumption and M Tomsic, “An MgB2 12.5 kVA superconductor transformer”, Supercond. Sci. Technol. 22 065002 (2009).
M. Majoros, Mike D. Sumption, M. A. Susner, M. Tomsic, M. Rindfleisch, and E. W. Collings, “AC Losses in MgB2 Multifilamentary Strands With Magnetic and Non-Magnetic Sheath Materials”, IEEE Trans. Appl. Supercond. 19 3106 (2009).
M. A. A. Mahmud, Mike A. Susner, Mike D. Sumption, Matthew A. Rindfleisch, Michael J. Tomsic, Jinji Yue, and Edward W. Collings, “Comparison of Critical Current Density in MgB2 With Different Boron Sources and Nano-Particle Dopant Additions”, IEEE Trans. Appl. Supercond. 19 2756 (2009).
S. Bhartiya, Mike D. Sumption, Xuan Peng, Eric Gregory, Michael J. Tomsic, and Edward W. Collings, “Investigation of the Effects of Low Temperature Heat Treatments on the Microstructure and Properties of Multifilamentary, Tube-Type Nb3Sn Strands”, IEEE Trans. Appl. Supercond. 19 2588 (2009).
M. Majoros, M. D. Sumption, E. W. Collings, and David Doll, “Numerical Modeling of the AC Limiting Properties of Insulated, Conduction Cooled MgB2 Strands”, IEEE Trans. Appl. Supercond. 19 1872 (2009).
Milan Majoros, Mike D. Sumption, and Edward W. Collings, “Transport AC Loss Reduction in Striated YBCO Coated Conductors by Magnetic Screening”, IEEE Trans. Appl. Supercond. 19 3352 (2009).
T.J. Haugan, F.J. Baca, M.J. Mullins, N.A. Pierce, T.A. Campbell, E.L. Brewster, P.N. Barnes, H. Wang, and M. D. Sumption, “Temperature and Magnetic Field Dependence of Critical Current Density of YBCO with Varying Flux Pinning Additions”, IEEE Trans. Appl. Supercond. 19 3270 (2009).
E.Gregory, M. Tomsic, X. Peng, M.D. Sumption, and A. Ghosh, “Nb3Sn Superconductors Made by an Economical Tubular Process”, IEEE Trans. Appl. Supercond. 19 2602 (2009).
M.D. Sumption, M. Susner, E.W. Collings, D.R. Dietderich, E. Barzi, D. Turrioni, R. Yamada, and A.V. Zlobin, “Effect of Cable Edge Deformation on RRR and Magnetization of Strands Extracted From Nb3Sn Rutherford-Type Cables”, IEEE Trans. Appl. Supercond. 19 2481 (2009).
M. Majoros, M. D. Sumption, M. A. Susner, S. Bhartiya, S. D. Bohnenstiehl, E. W. Collings, M. Tomsic, M. Rindfleisch, J. Phillips, D. Lyons, and J. Yue, “A Model Superconducting Helical Undulator Wound Using a Wind and React MgB2 Multifilamentary Wire”, IEEE Trans. Appl. Supercond. 19 1376 (2009).
M.D. Sumption, T.J. Haugan, P.N. Barnes, T.A. Campbell, N.A. Pierce, and C. Varanasi, “Magnetization Creep and Decay in YBa2Cu3O7−x Thin Films with Artificial Nanostructure Pinning, Phys. Rev. B 77, 094506 (2008).
E.W. Collings, M.D. Sumption, M. Bhatia, M.A. Susner and S.D. Bohnenstiehl, “Prospects for Improving the Intrinsic and Extrinsic Properties of Magnesium Diboride Superconducting Strands”, Supercond. Sci. Technol. 21 103001 (2008).
R. Zeng, L. Lu, W. X. Li, J. L. Wang, D. Q. Shi, J. Horvat, S.X. Dou, M. Bhatia, M. Sumption, E. W. Collings, J. M. Yoo, M. Tomsic, and M. Rindfleisch, “Excess Mg Addition MgB2 /Fe Wires with Enhanced Critical Current Density”, Journal of Applied Physics 103, 083911 (2008).
E.W. Collings, M.D. Sumption, E. Barzi, D. Turrioni, R. Yamada, A.V. Zlobin, Y. Ilyin, and A. Nijhuis, “Effect of Core Width, Placement, and Condition on Calorimetrically Measured AC Loss and Interstrand Contact Resistance of Stainless-Steel-Cored Nb3Sn Rutherford Cables”, IEEE Trans. Appl. Supercond. 18 1370 (2008).
D. Turrioni, E. Barzi, M. Bossert, E.W. Collings, V. Nazareth, M.D. Sumption, R. Yamada, and A.V. Zlobin, “Effects of Rutherford Cable Parameters on Nb3Sn Extracted Strand Deformation and Performance”, IEEE Trans. Appl. Supercond. 18 1114 (2008).
E. Gregory, M. Tomsic, X. Peng, R. Dhaka, V.R. Nazareth, and M.D. Sumption, “Niobium Tin Conductors for High Energy Physics, Fusion, MRI and NMR Applications Made by Different Techniques”, IEEE Trans. Appl. Supercond. 18 989 (2008).
E.W. Collings, M.D. Sumption, M.A. Susner, D.R. Dietderich, E. Barzi, A.V. Zlobin, Y. Ilyin, and A. Nijhuis, “Influence of a Stainless Steel Core on Coupling Loss, Interstrand Contact Resistance, and Magnetization of an Nb3Sn Rutherford Cable”, IEEE Trans. Appl. Supercond. 18 1301 (2008).
V.R. Nazareth, M.D. Sumption, X. Peng, E. Gregory, M.J. Tomsic, and E.W. Collings, “Characterization of the A15 Layer Growth and Microstructure for Varying Heat Treatments in Nb3Sn Tube Type Composites”, IEEE Trans. Appl. Supercond. 18 1005 (2008).
M. Tomsic, M. Rindfleisch, J.J. Yue, K. McFadden, J. Phillips, M.D. Sumption, M. Bhatia, S. Bohnenstiehl, and E.W. Collings, “Overview of MgB2 Superconductor Applications”, Int. J. Appl. Ceramic Tech. 4 250-259 (2007).
M. Tomsic, M. Rindfleisch, J.J. Yue, K. McFadden, D. Doll, J. Phillips, M.D. Sumption, M. Bhatia, S. Bohnenstiehl, and E.W. Collings, “Development of Magnesium Diboride (MgB2) Wires and Magnets Using in-situ Strand Fabrication Method”, Physica C 456 203-208 (2007).
M.A. Susner, M.D. Sumption, M. Bhatia, X. Peng, M. Tomsic, M.A. Rindfleisch, and E.W., Collings, “Influence of Mg/B Ratio and SiC Doping on Microstructure and High Field Transport J(c) in MgB2 strands”, Physica C 456 180-187 (2007).
M.D. Sumption, M. Bhatia, F. Buta, S. Bohnenstiehl, M. Tomsic, M. Rindfleisch, J. Yue, J. Phillips, S. Kawabata, and E.W. Collings, “Multifilamentary MgB2-Based Solenoidal and Racetrack Coils”, Physica C 458 12-20 (2007).
M.S.A. Hossain, J.H. Kim, X. Xu, X.L. Wang, M. Rindfleisch, M. Tomsic, M.D. Sumption, E.W. Collings, and S.X. Dou, “Significant Enhancement of Hc2 and Hirr in MgB2+C4H6O5 Bulks at a Low Sintering Temperature of 600 Degrees C” Supercond. Sci. Tech. 20 L51-L54 (2007).
M.D. Sumption, M.A. Susner, M. Bhatia, M.A. Rindfleisch, M.J. Tomsic, K.J. McFadden, and E.W. Collings, “High Critical Current Density Multifilamentary MgB2 Strands”, IEEE Trans. Appl. Supercond. 17 2838-2841 (2007).
M. Eisterer, K.R. Schoppl, H.W. Weber, M.D. Sumption, and M. Bhatia, “Neutron Irradiation of SiC Doped and Magnesium Rich MgB2 Wires” IEEE Trans. Appl. Supercond. 17 2814-2817 (2007).
S. Bohnenstiehl, S.A. Dregia, M.D. Sumption, and E.W. Collings, “Thermal Analysis of MgB2 Formation IEEE Trans. Appl. Supercond. 17 2754-2756 (2007).
M. Bhatia, M.D. Sumption, S. Bohnenstiehl, S.A. Dregia, E.W. Collings, M. Tomsic, and M. Rindfleisch, “Superconducting Properties of SiC Doped MgB2 Formed Below and Above Mg's Melting Point”, IEEE Trans. Appl. Supercond. 17 2750-2753 (2007).
M.D. Sumption and E.W. Collings, “Modeling Current-Field Instabilities in High Performance Nb3Sn Strands in Moderate Field”, IEEE Trans. Appl. Supercon. 17 2714-2717 (2007).
X. Peng, M.D. Sumption, R. Dhaka, M. Bhatia, M. Tomsic, E. Gregory, and E.W. Collings, “Composition Profiles and Upper Critical Field Measurement of Internal-Sn and Tube-Type Conductors”, IEEE Trans. Appl. Supercon. 17 2668-2671 (2007).
E. Gregory, B.A. Zeitlin, M. Tomsic, X. Peng, M.D. Sumption, and E.W. Collings, “Some Factors Involved in the Development of a Tubular Process for Nb3Sn Conductors”, IEEE Trans. Appl. Supercond. 17 2664-2667 (2007).
R.K. Dhaka, M.D. Sumption, X. Peng, E. Gregory, M. Tomsic, and E.W. Collings, “Experimental and Theoretical Investigation of the Diffusion of Sn in Internal-Tin Nb3Sn”, IEEE Trans. Appl. Supercon. 17 2655-2659 (2007).
E.W. Collings, M.D. Sumption, G. Ambrosio, Y. Ilyin, an A. Nijhuis, “Interstrand Contact Resistance in Nb3Sn Cables Under LARP-Type Preparation Conditions” IEEE Trans. Appl. Supercond. 17 2494-2497 (2007).
M.D. Sumption, S.A. Bohnenstiehl, F. Buta, M. Majoros, S. Kawabata, M. Tomsic, M. Rindfleisch, J. Phillips, J. Yue, and E.W. Collings, “Wind and React and React and Wind MgB2 Solenoid, Race Track and Pancake Coils”, IEEE Trans. Appl. Supercond. 17 2286-2290 (2007).
M. Majoros, L. Ye, A.A. Campbell, T.A. Coombs, M.D. Sumption, and E.W. Collings, “Modeling of Transport AC Losses in Superconducting Arrays Carrying Anti-parallel Currents”, IEEE Trans. Appl. Supercond. 17 1803-1806 (2007).
M. Majoros, L. Ye, A.A. Campbell, T.A. Coombs, A.V. Velichko, D.M. Astill, P. Sargent, M. Haslett, M.D. Sumption, E.W. Collings, M. Tomsic, S. Harrison, and M. Husband, “Fault Current Limiting Properties of MgB2 Superconducting Wires” IEEE Trans. Appl. Supercond. 17 1764-1767 (2007).
M. Majoros, L. Ye, A.V. Velichko, T.A. Coombs, M.D. Sumption, and E.W. Collings, “Transport AC Losses in YBCO Coated Conductors”, Supercond. Sci. Tech. 20 S299-S304 (2007).
C.V. Varanasi, J. Burke, L. Brunke, H. Wang, M. Sumption, and P.N. Barnes, “Enhancement and Angular Dependence of Transport Critical Current Density in Pulsed Laser Deposited YBa2Cu3O7-x+BaSnO3 Films in Applied Magnetic Fields”, J. Appl. Phys. 102 063909 (2007).
M.D. Sumption, S. Kawabata, and E.W. Collings, “AC Loss in YBCO Coated Conductors Exposed to External Magnetic Fields at 50-200 Hz”, Physica C, 466 (1-2): 29-36 (2007).
Y. Iwasa, D.C. Larbalestier, M. Okada, R. Penco, M. D. Sumption, and X. Xi, “A Round Table Discussion on MgB2, Toward a Wide Market or a Niche Production?—A Summary”, IEEE Trans. Appl. Supercond. 16, 1457-1461 (2006).
E. W. Collings, S. Kawabata, M. Bhatia, M. Tomsic, and M. D. Sumption, “Magnesium Diboride Superconducting Strand for Accelerator and Light Source Applications”, IEEE Trans. Appl. Supercond. 16, 1445-1449 (2006).
E. W. Collings, M. D. Sumption, D. R. Dietderich, Y. Ilyin, and A. Nijhuis, “Magnetic Measurements of Interstrand Contact Resistance in Nb3Sn Cables in Response to Variation of Pre-Heat-Treatment Condition”, IEEE Trans. Appl. Supercond. 16, 1200-1204 (2006).
M.D. Sumption, M. Bhatia, M. Rindfleisch, M. Tomsic, E.W. Collings, “Transport Properties of Multifilamentary, in-situ route, Cu-Stabilized MgB2 Strands: one Metre Segments and the J(c)(B,T) Dependence of Short Samples”, Supercond. Sci. Tech. 19 155-160 (2006).
Shcherbakova, S.X. Dou, S. Soltanian, D. Wexler, M. Bhatia, M.D. Sumption, E.W. Collings, “The Effect of Doping Level and Sintering Temperature on Jc(H) Performance in Nano-SiC Doped and Pure MgB2 Wires”, J. Appl. Phys. 99 08M510 (2006).
P.N. Barnes, G.L. Rhoads, J.C. Tolliver, M.D. Sumption, and K.W. Schmaeman, “Compact, Lightweight, Superconducting Power Generators”, IEEE Transactions on Magnetics 41 268-273 (2005).
M.D. Sumption, M. Bhatia, X. Wu, M. Rindfleisch, M. Tomsic and E.W. Collings, “Multifilamentary, in-situ Route, Cu-Stabilized MgB2 Strands”, Supercond. Sci. Technol. 18 730-734 (2005).
S. Soltanian, X.L. Wang, J. Horvat, S.X. Dou, M.D. Sumption, M. Bhatia, E.W. Collings, P. Munroe, and M. Tomsic, “High Transport Critical Current Density and Large Hc2 and Hirr in Nanoscale SiC doped MgB2 Wires Sintered at Low Temperature”, Supercond. Sci. Technol. 18 658-666 (2005).
P.N. Barnes, T.J. Haugan, M.D. Sumption, and B.C Harrison, “Pinning Enhancement of YBa2Cu3O7-d Thin Films with Y2BaCuO5 Nanoparticulates”, IEEE Trans. Appl. Supercond. 15 3766-3769 (2005).
X. Peng, M.D. Sumption, and E.W. Collings, “Magnetization and deff in Multifilamentary Nb3Sn strands”, IEEE Trans. Appl. Supercond. 15 3498-3501 (2005).
E. Gregory, M. Tomsic, M.D. Sumption, X. Peng, X. Wu, E. W. Collings, and B. A. Zeitlin, “The Introduction of Titanium into Internal-Tin Nb3Sn by a Variety of Procedures”, IEEE Trans. Appl. Supercond.15 3478-3481 (2005).
X. Peng, M.D. Sumption, and E.W. Collings, “Finite Element Analysis of Drawing of Multifilamentary Wires”, IEEE Trans. Appl. Supercond. 15 3426-3429 (2005).
X. Peng, M.D. Sumption, M. Tomsic, E. Gregory, and E. W. Collings, “Microstructural Investigation of Internal-Tin Nb3Sn Strands”, IEEE Trans. Appl. Supercond. 15 3422-3425 (2005).
X. Wu, X. Peng, M.D. Sumption, M. Tomsic, E. Gregory, and E. W. Collings, “Ti and Sn Diffusion and its Influence on Phase Formation in Internal-tin Nb3Sn Superconductor Strands”, IEEE Trans. Appl. Supercond. 15 3399-3402 (2005).
F. Buta, M.D. Sumption, and E.W. Collings, “Flux Pinning in RHQT-Processed Nb3Al after Various Transformation Heat Treatments”, IEEE Trans. Appl. Supercond.15 3380-3384 (2005).
M. Bhatia, M.D. Sumption, and E.W. Collings, “Effect of Various Additions on Upper Critical Field and Irreversibility Field of in-situ MgB2 Superconducting Bulk Material”, IEEE Trans. Appl. Supercond. 15 3204-3206 (2005).
P.N. Barnes, G.A. Levin, C. Varanasi, and M.D. Sumption, “Low AC Loss Structures in YBCO Coated Conductors with Filamentary Current Sharing”, IEEE Trans. Appl. Supercond. 15 2827-2830 (2005).
M.D. Sumption, P.N. Barnes, and E.W. Collings, “AC Losses of Coated Conductors in Perpendicular Fields and Concepts for Twisting”, IEEE Trans. Appl. Supercond. 15 2815-2818 (2005).
M.D. Sumption, M. Bhatia, M. Rindfleisch, J. Phillips, M. Tomsic, and E. W. Collings “MgB2/Cu Racetrack Coil Winding, Insulating, and Testing”, IEEE Trans. Appl. Supercond. 15 1457-1460 (2005).
X.L. Wang, A.H. Li, S. Yu, S. Ooi, K. Hirata, C.T. Lin, E.W. Collings, M.D. Sumption, M. Bhatia, S.Y. Ding, and S.X. Dou, “Thermally Assisted Flux Flow and Individual Vortex Pinning in Bi2Sr2Ca2Cu3O10 Single Crystals Grown by the Traveling Solvent Floating Zone Technique”, J. Appl. Phys. 97 10B114 (2005).
A.H. Li, H.K. Liu, M. Ionescu, X.L. Wang, S.X. Dou, E.W. Collings, M.D. Sumption, M. Bhatia, Z.W. Lin, and J.G. Zhu, “Improvement of Critical Current Density and Thermally Assisted Individual Vortex Depinning in Pulsed-Laser-Deposited YBa2Cu3O7-d Thin Films on SrTiO3 (100) Substrate with Surface Modification by Ag Nanodots”, J. Appl. Phys. 97 10B107 (2005).
M. Bhatia, M.D. Sumption, E. W. Collings, and S. Dregia, “Increases in the Irreversibility Field and the Upper Critical Field of Bulk MgB2 by ZrB2 Addition”, Appl. Phys. Lett. 87 042505 (2005).
M.D. Sumption, M. Bhatia, F. Buta, S Bohnenstiehl, M Tomsic, M. Rindfleisch, J. Yue, J. Phillips, S. Kawabata and E.W. Collings, “Solenoidal Coils Made from Monofilamentary and Multifilamentary MgB2 Strands”, Supercond. Sci. Tech. 18 961-965 (2005).
P.N. Barnes, M.D. Sumption, and G.L. Rhoads, “Review of High Power Density Superconducting Generators: Present State and Prospects for Incorporating YBCO Windings”, Cryogenics 45 670-686 (2005).
M.D. Sumption, M. Bhatia, M. Rindfleisch, M. Tomsic, and E.W. Collings, “Transport and Magnetic Jc of MgB2 Strands and Small Helical Coils”, Appl. Phys. Let. 86 102501 (2005).
M.D. Sumption, M. Bhatia, M. Rindfleisch, M. Tomsic, S. Soltanian, S.X. Dou, and E.W. Collings, “Large Upper Critical Field and Irreversibility Field in MgB2 Wires with SiC Additions”, Appl. Phys. Let. 86 92507 (2005).
M.D. Sumption, E.W. Collings, and P. Barnes, “AC Loss in Striped (Filamentary) YBCO Coated Conductors Leading to Designs for High Frequencies and Field-Sweep Amplitudes”, Supercond. Sci. Tech. 18 122 (2005).
J. Fang, X.M. Luo, D.X. Chen, Et Al., “AC Magnetic Losses In Bi-2223/Ag Tapes with Different Aspect Ratios”, Physica C 412-414 1134-1138 ( 2004).
J. Fang, X.M. Luo, D.X. Chen, Et Al., Geometry Dependence of Magnetic and Transport AC Losses in Bi-2223/Ag Tapes with Different Aspect Ratios”, Supercond. Sci. Technol. 17 1173-1179 (2004).
T. Haugan, P.N. Barnes, R. Wheeler, F. Meisenkothen, and M. Sumption, “Addition of Nanoparticle Dispersions to Enhance Flux Pinning of the YBa2Cu3O7-X Superconductor”, Nature 430 867-870 (2004).
P.N. Barnes and M.D. Sumption, “Low Loss Striated YBa2Cu3O7-d Coated Conductor with Filamentary Current Sharing”, J. Appl. Phys. 96 6550-6556 (2004).
M. Bhatia, M.D. Sumption, M. Tomsic, and E.W. Collings, “Influence of Heat Treatment Schedules on Magnetic Jc and Phase Formation in Bulk MgB2“, Physica C, 415 158-162 (2004).
M. Bhatia, M.D. Sumption, M. Tomsic, and E.W. Collings, “Influence of Heat Treatment Schedules on the Transport Current Densities of Long and Short Segments of Superconducting MgB2 Wire”, Physica C 407 153-159 (2004).
E.W. Collings, M.D. Sumption, and T. Tajima, “Magnesium Diboride Superconducting RF Resonant Cavities for High Energy Particle Acceleration”, Supercond. Sci. Technol. 17 S595-S601 (2004).
M.D. Sumption, M. Bhatia, S .X. Dou, M. Rindfleisch, M. Tomsic, L. Arda, M. Ozdemir, Y. Hascicek and E.W. Collings, “Irreversibility Field and Flux Pinning in MgB2 with and without SiC Additions”, Supercond. Sci. Technol. 17 1180–1184 (2004)
M.D. Sumption and E.W. Collings, “Stability and Instability in High Performance (Metastable) Composite Strands During I-V Measurement”, Physica C 401 66-74 (2004).
M.D. Sumption, X. Peng, E. Lee, X. Wu, and E.W. Collings, “Analysis of Magnetization, AC Loss, and deff for Various Internal-Sn Based Nb3Sn Multifilamentary Strands with and without Subelement Splitting”, Cryogenics 44 711-725 (2004).
M.D. Sumption and E.W. Collings, “Stability and Instability in High Performance (Metastable) Composite Strands During I-V Measurement”, Physica C 401 66-74 (2004).
E. Lee, M.D. Sumption, and E.W. Collings, “Temperature and Field Dependence of the Effective Matrix Resistivity of Bi:2223/Ag Composites”, IEEE Appl. Supercond. 13 3614-3617 (2003).
X. Peng, M.D. Sumption, and E.W. Collings, “Finite Element Modeling of Hydrostatic Extrusion for Mono-Core Superconductor Billets”, IEEE Trans. Appl. Supercond. 13 3434-3437 (2003).
A. Kikuchi, Y. Iijima, K. Inoue, F. Buta, M.D. Sumption, and E.W. Collings, “Nb3Sn Wires Synthesized by Rapid-Heating/Quenching Process of Rod-In-Tube Wire Precursors”, IEEE Trans. Appl. Supercond. 13 3430-3433 (2003).
E.W. Collings, E. Lee, M.D. Sumption, M. Tomsic, “Continuous- and Batch-Processed MgB2/Fe Strands - Transport and Magnetic Properties”, Physica C 386 555-559 (2003).
M.D. Sumption and E.W. Collings, “Stability and Flux Jumping of Internal-Sn, Nb3Sn Conductors (and a Model System, MgB2)”, IEEE Trans. Appl. Supercond. 13 3394-3397 (2003).
M.D. Sumption, X. Peng, E. Lee, F. Buta, E.W. Collings, and M. Tomsic, “Fabrication and Properties of PIT Nb-Al and Nb-Sn Based Superconductors”, IEEE Trans. Appl. Supercond. 13 3486-3489 (2003).
M.D. Sumption, F. Buta, M. Tomsic, A. Austen, E. Gregory, M. Rudziak, T. Wong, L. Motowidlo, Y. Hascicek, R. M. Scanlan, H. Higley, and E.W. Collings, “Nb3Al Strand Processing, Transport Properties, and Cabling”, IEEE Trans. Appl. Supercond. 13 3466-3469 (2003).
F. Buta, M. D. Sumption, and E. W. Collings, “Influence of Transformation Heat Treatment on Microstructure and Defects in RHQT-Processed Nb3Al”, IEEE Trans. Appl. Supercond. 13 3458-3461 (2003).
F. Buta, M. D. Sumption, and E. W. Collings, “Phase Stability at High Temperatures in the Nb-Al System”, IEEE Trans. Appl. Supercond. 13 3462-3465 (2003).
S. Soltanian, X.L. Wang, A.H. Li, E.W. Collings, M.D. Sumption, E. Lee, H.K. Liu, and S.X. Dou , “Fabrication and Critical Current Density in 16-Filament Stainless Steel/Fe/MgB2 Square Wire”, Solid State Commun. 124 59-62 (2002).
E.W. Collings, E. Lee, X.L. Wang, and M.D. Sumption, “Real and Apparent Loss Suppression in MgB2 Superconducting Composites”, Physica C 382 98-103 (2002).
M.D Sumption, E.W. Collings, and E. Lee, “Reduction and Elimination of External-Field AC Loss in MgB2/Fe Wire by in-situ Magnetic Shielding”, Physica C 378-381 894-898 (2002).
E.W. Collings, E. Lee, M.D. Sumption, and M. Tomsic, “Transport and Magnetic Properties of Continuously Processed MgB2“, Rare Metal Mat. Eng. 31 406-409 (2002).
H. Harada, T. Nakano, M. Tsuda, T. Hamajima, F. Buta, E. Lee, M.D. Sumption, E.W. Collings, K. Tagawa, H. Moriai, T. Takeuchi, H. Wada, and K. Watanabe, “Influence of Rapid Heating Condition on Superconducting Properties in Transformed Jelly-Roll Nb3Al Multifilamentary Wire”, IEEE Trans. Appl. Supercond. 12 1033-1036 (2002).
M.D. Sumption, E.L. Coleman, C.B. Cobb, P.N. Barnes, T.J. Haugan, J. Tolliver, C.E. Oberly, and E.W. Collings, “Hysteretic Loss vs. Filament Width in Thin YBCO Films Near the Penetration Field”, IEEE Trans. Appl. Supercond. 13 3553-3556 (2003).
T. Haugan, P.N. Barnes, I. Maartense, C.B. Cobb, E.J. Lee, and M.D. Sumption, “Island Growth Of Y2BaCuO5 Nanoparticles in (211(~1.5 nm)/123(~10nm))Xn Composite Multilayer Structures to Enhance Flux Pinning of YBa2Cu3O7-d Films”, J. Mat. Res. 18 2618-2623 (2003).
C.B. Cobb, P.N. Barnes, T.J. Haugan, J. Tolliver, E. Lee, M.D. Sumption, E.W. Collings, and C.E. Oberly, “Hysteretic Loss Reduction in Striated YBCO”, Physica C 382 52-56 (2002).
M.D. Sumption, E.W. Collings, R.M. Scanlan, S.W. Kim, M. Wake, T. Shintomi, A. Nijhuis, and H.H.J. Ten Kate, “AC Loss in Cored Stabrite Cables in Response to External Compaction and Variation of Core Thickness and Width”, Cryogenics 41 733-744 (2001).
M.D. Sumption, R.M. Scanlan, and E.W. Collings, “Coupling Loss and Contact Resistance in Cored Stabrite Cables -- Influences of Compaction and Variation of Core Width”, IEEE Trans. Appl. Supercond. 11 2571-2574 (2001).
S. Soltanian, X.L. Wang, I. Kusevic, E. Babic, A.H. Li, M.J. Qin, J. Horvat, H.K. Liu, E.W. Collings, E. Lee, M.D. Sumption, and S.X. Dou, “High Transport Critical Current Density above 30 K in Pure Fe-Clad MgB2 Tape”, Physica C 361 84-90 (2001).
M.D. Sumption, E.W. Collings, R.M. Scanlan, S.W. Kim, M. Wake, T. Shintomi, A. Nijhuis, and H.H.J. Ten Kate, “AC Loss and Interstrand Contact Resistance in Bare and Coated NbTi/Cu Rutherford Cables with Cores”, Supercond. Sci. Tech. 14 888-897 (2001).
E.W. Collings and M.D. Sumption, “Static and Dynamic Parasitic Magnetizations and their Control in Superconducting Accelerator Dipoles”, Physica C 354 60-65 (2001).
E.W. Collings and M.D. Sumption, “Transverse Resistivities an Untwisted HTSC Tapes at 4.2, 30, and 60 K”, Physica C 357-360 1153-1159 (2001).
M.D. Sumption, E. Lee, and E.W. Collings, “Analysis of Eddy Current AC Loss for Untwisted, Multifilamentary Superconducting Composites with Various Aspect Ratios”, IEEE Trans. Appl. Supercond. 11 2963-2966 (2001).
S.X. Dou, X.L. Wang, J. Horvat, D. Milliken, A.H. Li, K. Konstinov, E.W. Collings, M.D Sumption, and H.K. Liu, “Flux Jumping and a Bulk-To-Granular Transition in the Magnetization of a Compacted and Sintered MgB2 Superconductor”, Physica C 361 79-83 (2001).
E.W. Collings, M.D. Sumption, and E. Lee, “Magnetization as a Critical Defining Parameter for Strand in Precision Dipole Applications -- Implications for Field Error and F-J Stability”, IEEE Trans. Appl. Supercond. 11 2567-2570 (2001).
F. Buta, M.D. Sumption, and E.W. Collings, “Studies for Processing Nb3Al Using a Rapid Ohmic-Heating and Quenching Method”, IEEE Trans. Appl. Supercond. 11 3980-3983 (2001).
N. Harada, T. Nakano, M. Tsuda, T. Hamajima, F. Buta, E. Lee, M.D. Sumption, E.W. Collings, K. Tagawa, H. Moriai, T. Takeuchi, H. Wada, and K. Watanabe, “Superconducting Properties and Rapid Heating Condition in Transformed Jelly-Roll Nb3al Multifilamentary Wires as a Function of Maximum Ohmic-Heating Temperature”, IEEE Trans. Appl. Supercond. 11 3611-3614 (2001).
M.D. Sumption, E. Lee, S.X. Dou, and E.W. Collings, “Extraction of Matrix Resistivity from Short Samples of Superconducting Multifilamentary Composite Tapes: Influence of Strand Twist Pitch and Internal Structure”, Physica C 335 164-169 (2000).
M.D. Sumption, R.M. Scanlan, A. Nijhuis, and E.W. Collings, “AC Loss and Contact Resistance in Copper Stabilized Nb3Al Rutherford Cables with and without a Stainless Steel Core”, IEEE Trans Appl. Supercond. 10 1196-1199 (2000).
M.D. Sumption, E.W. Collings, A. Nijhuis, and R.M. Scanlan, “Coupling Current Control in Stabrite-Coated NbTi Rutherford Cables by Varying the Width of a Stainless Steel Core”, Adv. Cryo. Eng. 46 1043-1049 (2000).
M.D. Sumption, E. Lee, and E.W. Collings, “Influence of Filamentary and Strand Aspect Ratios on AC Loss in Short, Untwisted Samples of HTSC and LTSC Superconducting Multifilamentary Composites”, Physica C 337 187-194 (2000).

E.W. Collings, M.D. Sumption, R.M. Scanlan, D.R. Dietderich, L.R. Motowidlo, R.S. Sokolowski, Y. Aoki, and T. Hasegawa, “Bi:2212/Ag-Based Rutherford Cables: Production, Processing, and Properties”, Supercond. Sci. Technol. 12 87-96 (1999).
M.D. Sumption, E.W. Collings, R.M. Scanlan, A. Nijhuis, and H.H.J. Tenkate, “Core Suppressed AC Loss and Strand-Moderated Contact Resistance in a Nb3Sn Rutherford Cable”, Cryogenics 39 1-12 (1999).
M.D. Sumption, E.W. Collings, and E. Gregory, “Low Field Flux Jumping in High Performance Multifilamentary Nb3Al and Nb3Sn Composite Strands”, IEEE Trans. Appl. Supercond. 9 1455-1458 (1999).
E.W. Collings, M.D. Sumption, R.M. Scanlan, D.R. Dietderich, and L.R. Motowidlo, “Low Coupling Loss Core-Strengthened Bi:2212/Ag Rutherford Cables”, IEEE Trans. Appl. Supercond. 9 758-761 (1999).
E. Gregory, M. Tomsic, F. Buta, M.D. Sumption, and E.W. Collings, “Process Development and Microstructures of Nb3Al Precursor Strand for Reel-To-Reel Production”, IEEE Trans. Appl. Supercond. 9 2692-2695 (1999).
F. Buta, M.D. Sumption, E.W. Collings, N, Harada, E. Gregory, and M. Tomsic, “Short Sample Quenching of Nb3al Precursor Strand in Support of Reel-To-Reel Process Development”, IEEE Trans. Appl. Supercond 9 1433-1436 (1999).
M.D. Sumption, E.W. Collings, R.M. Scanlan, A. Nijhuis, H.H.J. Ten Kate, S.W. Kim, M. Wake, and T. Shintomi, “Influence of Strand Surface Condition on Interstrand Contact Resistance and Coupling Loss in NbTi-Wound Rutherford Cables”, Cryogenics 39 197-208 (1999).
M.D. Sumption and S. Takacs, “Flux Pinning in the Weak Layers of Superconducting Heterogeneous Structures”, Physica C 316 129-151 (1999).
M.D. Sumption, R.M. Scanlan, and E.W. Collings, “AC Loss Properties of Some Bi:2212/Ag Rutherford Cables and a Comparison of Those with Cables Wound with NbTi and Nb3Sn”, Cryogenics 38 1225-1232 (1998).
M.D. Sumption, S. Takacs, and E.W. Collings, “Modelling of M-H Loop Anomalies in Synergistically Pinned, Heterogeneous, Composite Superconductors”, Physica C 306 300-308 (1998).
M.D. Sumption, R.M. Scanlan, and E.W. Collings, “Coupling Current Control in Rutherford Cables Wound With NbTi, Nb3Sn, and Bi:2212/Ag”, Physica C 310 291-295 (1998).
M.D. Sumption, L.R. Motowidlo, and E.W. Collings, “Determination of the True (or Potential) Transport-Jc of a Multifilamentary Bi-HTSC/Ag Strand in the Presence of Bridging and Generalized Sausaging”, Physica C 291 267-273 (1997).
M.D. Sumption, E.W. Collings, E. Gulko, T. Pyon, and E. Gregory, “Analysis of Optically and Magnetically Determined Bridging in Internal-Tin Process Nb3Sn Strands, IEEE Trans. Appl. Supercond. 7 1368-1371 (1997).
M.D. Sumption, and E.W. Collings, “Effect Current Strengths in NbTi Multifilamentary Samples with and without Nb Barriers and Processed Under Various Conditions”, IEEE Trans. Appl. Supercond. 7 1117-1121 (1997).
E.W. Collings, M.D. Sumption, S.W. Kim, M. Wake, T. Shintomi, A. Nijhuis, H.H.J. Ten Kate, and R.M. Scanlan, “Suppression and Control of Coupling Currents in Stabrite-Coated Rutherford Cable With Cores of Various Materials and Thicknesses”, IEEE Trans. Appl. Supercond. 7 962-966 (1997).
E.W. Collings, M.D. Sumption, K. Itoh, H. Wada, and K. Tachikawa”, Second VAMAS AC Loss Measurement Intercomparison: Magnetization Measurement of Low-Frequency (Hysteretic) AC Loss in NbTi Multifilamentary Strands”, Cryogenics 37 49-60 (1997).
M.D. Sumption and E.W. Collings, “Anomalous Magnetic Properties and Proximity Effect Coupling in VAMAS Strands, Cryogenics 37 165-170 (1997).
M.D. Sumption and E.W. Collings, ”A Model for Bridging and Coupling in Superconductors”, Physica C 261 245-258 (1996).
L.R. Motowidlo, G. Galinsky, G. Ozeryansky, W. Zhang, E.E. Hellstrom, M.D. Sumption, and E.W. Collings, “The Influence of Filament Size and Atmosphere on the Microstructure and Jc of Round Filament Bi2Sr2Ca1Cu2Ox Wires”, IEEE Trans. Applied Supercond. 5 1162 (1995).
E.W. Collings and M.D. Sumption, “Stability and AC Losses in HTSC/Ag Multifilamentary Strands”, Applied Superconductivity 5 551-557 (1995).
E. Gregory, E.A. Gulko, T. Pyun, M.D. Sumption, and E.W. Collings, “Dual Barrier for the Suppression of Residual Resistance Degradation in Chrome-Plated Niobium-Tin Strands”, IEEE Trans. Appl. Supercond. 5 1921-1924 (1995).
E.W. Collings, M.D. Sumption, K. Itoh, H. Wada, and K. Tachikawa, “Report on the Second VAMAS AC Loss Round Robin -- Magnetization Measurement of Low-Frequency Hysteretic Loss”, IEEE Trans. Appl. Supercond. 5 540-544 (1995).
M.D. Sumption and E.W. Collings, “A Comparison of AC Loss, Magnetization, Hr, and U0 for Bi:2212 Wires, Crystals, and Melt Grown Samples, Applied Superconductivity 3, 521-533 (1995).
E.W. Collings and M.D. Sumption, “Materials Selection for Ferromagnetic Compensation in Accelerator Magnets”, IEEE Trans. Appl. Supercond. 5 408-411 (1995).
M.D. Sumption, H.H.J. Tenkate, R.M. Scanlan, and E.W. Collings, “Contact Resistance and Cable Loss Measurement of Coated Strands and the Cables Wound From Them”, IEEE Trans. Appl. Supercond. 5 692-696 (1995).
M.D. Sumption and E.W. Collings, “Chromium Diffusion into Plated NbSn Strands Deduced From Electrical Resistivity Measurement”, IEEE Trans. Appl. Supercond. 5 1925-1928 (1995).
M.D. Sumption, “Calculation of the Magnetization of Anisotropic Superconductors with Cylindrical Geometry in Transverse Fields”, Applied Superconductivity 2 41-46 (1994).
M.D. Sumption and E.W. Collings, “Creep in Superconductive Composites with Anisotropic Pinning Potentials”, J. Appl. Phys., 76 4766 (1994).
M.D. Sumption and E.W. Collings, “Influence of Ni Additions on the Low Temperature Magnetic Properties of A Cu-1%Ni Alloy”, J. Appl. Phys. 76 7461 (1994).
M.D. Sumption and E.W. Collings, “Influence of Twist-Pitch and Sample Length on Proximity Effect Coupling in Multifilamentary Composites Described in Terms of a Field-Independent, Two-Current-Region Model”, Cryogenics 34, 491-505 (1994).
M.D. Sumption and E.W. Collings, “Innovative Strand Design for Accelerator Magnets”, Int. J. Mod. Phys. A (Proc. Suppl.) 2B, 662-664 (1993).
M.D. Sumption, K.R. Marken, Jr., and E.W. Collings, “Enhanced Static Magnetization and Creep in SCC-Type Strands via Cable and Twist Pitch Assisted Proximity Effects”, IEEE Trans. Appl. Supercond. 3 751-756, (1993).
M.D. Sumption, D.S. Pyun, and E.W. Collings, “Transverse and Longitudinal Resistivities in NbTi Multifilamentary Strands with Cu and CuMn Matrices”, IEEE Trans. Appl. Supercond. 3 859-862 (1993).
E.W. Collings, M.D. Sumption, and W.J. Carr, Jr., “Hysteretic Method of Lower Critical Field Determination in High Tc Superconductors”, Supercond. Sci. Technol. 5 S248-255 (1992).
E.W. Collings and M.D. Sumption, “AC Loss and Transverse Resistivity in Multifilamentary Strands with Matrices of Cu and CuMn”, Cryogenics 32 585-588 (1992).
E.W. Collings and M.D. Sumption, “Advanced Strand Design for Precision DC-Field and Ramp-Field Magnets, IEEE Trans. Magn. 28, 156-159 (1992).
E.W. Collings, K.R. Marken, Jr., M.D. Sumption, G. Iwaki, and S. Sakai, “Design, Fabrication, and Properties of Magnetically Compensated SSC Strands, IEEE Trans. Magn. 27, 1787-1790 (1991).
K.R. Marken, A.J. Markworth, M.D. Sumption, E.W. Collings, and R.M. Scanlan, “Eddy-Current Effects in Twisted and Wound SSC Strands, IEEE Trans. Magn. 27, 1791-1795 (1991).
M.D. Sumption, K.R. Marken, Jr., and E.W. Collings, “Position and Amplitude of Proximity Effect Peaks in the Magnetization Curves of NbTi/Cu and NbTi/CuMn Multifilamentary Strands, IEEE Trans. Magn. 27, 1129-1132 (1991).
M.D. Sumption, K.R. Marken, Jr., and E.W. Collings, “Hysteretic Surface Effects in Multifilamentary NbTi Wires Exposed to Transverse Applied Fields”, IEEE Trans. Appl. Magn. 27, 2166-2169 (1991).
E.W. Collings, K.R. Marken, Jr., and M.D. Sumption, “Interfilament and Intrafilament Magnetizations in Fine-Filament Composite Strands for Precision-Dipole Magnet Applications”, Cryogenics 30, 48-55, (1990).

Sumption, Michael

Professor, Materials Science and Engineering

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Electronic, photonic, magnetic materials

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(614) 688-3684

sumption.3@osu.edu

Collings, Edward

Adjunct Professor, Materials Science and Engineering

Research Scientist, Materials Science and Engineering

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(614) 688-3701

collings.2@osu.edu

AC Loss Studies

Figure 1. External field AC loss rig (left), solenoid primary (middle) and pick-up coil assembly (right).

Figure 2. Racetrack coil (top) racetrack pickup assembly (bottom) and coil for dynamic resistance measurements (right).

AC loss measurements are important for superconductors to be used in power transmission lines or other parts of the energy grid (transformers, fault current limiters, motors, generators, etc). Additionally, various mission agencies are interested in higher frequency AC loss performance of superconductors. We have focused our loss measurements on two materials, YBCO and MgB2. Shown in Figure 1 is the external loss rig, capable of 200 Hz and 150 mT. We have also developed a racetrack coil and a coil with in plane access for related external field loss measurements (Figure 2).

Figure 3. AC loss of YBCO samples with different amounts of Cu stabilizer. [Click to expand]

Figure 4. AC loss of YBCO samples with forty striations. [Click to expand]

Stability Studies

Figure 5. AC losses of MgB2 samples by various techniques. [Click to expand]

Figure 6. A YBCO coil would for NZP and thermal propagation measurements, instrumented with voltage taps and thermocouples, ready for measurement (coil made by Hyper Tech).

Stability is also a crucial matter for superconductors. For YBCO and MgB2, the normal zone propagation is slower than for NbTi and Nb3Sn, YBCO has a particularly low NZP. We have studied the values for radial and tangential NZP using a YBCO coil. In addition, high thermal conductivity insulation was used, in an attempt to increase radial NZP. One of the coils measured is shown in Figure 6, instrumented with voltage taps and thermocouples.

These studies were supported by the AFOSR under various programs, and by the Navy.

Figure 7. Quench propagation results for YBCO coil showing clear radial propagation. [Click to expand]

Figure 8. Summary of quench propagation results for YBCO coil. [Click to expand]

The CSMM is involved in the measurement of losses and the associated contact resistances in Nb₃Sn cables. A typical Rutherford type Nb₃Sn cable is shown in Figure 1 (in cross section). Here we see individual Nb₃Sn strands (about 0.7 microns across) in a flat cable geometry with a stainless steel separator. Figure 2 shows the samples being mounted in a reaction fixture. Such samples are obtained via collaboration either with LBNL’s Superconducting Magnet group or in collaboration with Fermilab.

Fig. 1. Nb3Sn 20 kA cable under study for AC loss and Stability

Fig. 2. Cable HT and pressurization Fixture

The samples are then pressurized and reacted (FNAL or LBNL) and sent back to OSU for re-pressurization (Figure 3) and epoxy impregnation. AC loss and contact resistance measurements are then made by OSU personnel at our collaborators the low temperature division of the University of Twente.

Fig 3. Cables are pressurized twice, once prior to reaction (at FNAL) and once before epoxy impregnation (at OSU).

Fig. 4. AC loss vs frequency showing that cable cores suppress AC loss and related magnetization, in collaboration with colleagues at the University of Twente, Low Temperature Division (Measurements made there, sample holder at right).

CSMM has also started a project to develop undulator coils in collaboration with a commercial partner Hyper Tech Research (HTR). A small model coil is shown (Fabricated at HTR) being prepared for measurement. Field profiles are calculated for these undulator coil geometries, the results are also shown in Figure 5 and Figure 6. Such coils are the Nb₃Sn research version related to the larger full size coils to be used in the International Linear Collider, the ILC.

Fig 5. Model Undulator Coil (Fabricated at HTR) and FEM Calculation of resultant Field — Fig 5. Model Undulator Coil (Fabricated at HTR) and
FEM Calculation of resultant Field

Fig. 6. Field Profile for Undulator Coil

Efforts at the allied SuTC have focused on MgB₂ related coils for energy and medical applications. Figure 7 shows a rotor coil relevant to the new all electric aircraft research underway at NASA. Figures 8 and 9 show other MgB₂ based coils for various applications.

Fig. 7. Cut-away of Rotor Coil (Fabricated by HTR)

Fig. 8. MgB2 based solenoidal coil (Fabricated by HTR).

Fig. 9. Open Winding based on MgB2 (Fabricated by HTR).

Nb₃Sn based superconducting materials are of strong interest as conductor for the High Energy Physics community, for the fabrication of beam steering (dipole) and focusing (quadrupole) magnets for particle accelerators. They also are of interest for high field NMR machines and Fusion reactors, and have possible applications in advanced MRI machines. The basic phase of interest is the A15 phase with 25 at% Sn, as shown in Figure 1. In order to have optimal properties, Sn content must be maximized.

Fig. 1. Nb-Sn binary phase diagram determined by Charlesworth et. al.

While bronze route conductors are of some interest for high field NMR, the highest performance conductor presently available is a Rod-In Tube based conductor, as shown in Figure 2. Conductors of this type have been produced commercially for some time. The CSMM is working with several industrial companies to optimize performance in these conductors, presently, the conductors have reached 3450 A/mm2 at 12 T and 4.2 K.

Fig. 2. RIT restack with 61 subelements (left) and expanded view of subelement (right). SEM Micrographs taken by CSMM personnel via access to the extensive CEOF facilities

Fig. 3. Transport properties of recent conductors developed at OSU and a local industrial consortium (Supergenics, Hyper Tech, and Global R&D).

While these properties are at the forefront of Nb3Sn transport performance, there are other needs for the HEP community. In order to minimize beam defocusing, and also to retain electromagnetic stability, it is necessary to minimize filament diameter (to reduce magnetization and flux jumps). A new (or perhaps newly improved) approach, name the “Tube” has led to conductors with up to 900 filaments and transport properties up to 2500 A/mm2. The RIT conductors form the A15 phase by a diffusion reaction involving first the formation of a bronze (in-situ) and then the reaction to A15. On the other hand the Tube conductors form by transforming from Nb6Sn5 (or perhaps NbSn2 -> Nb6Sn5) to the A15. The two different routes can be seen in Figure 4. It can be noted that this reaction route has some similarities (and differences from) a Powder in Tube based route. Some of the microstructures developed during the reaction to A15 are shown in Figure 5.

Fig. 4. Cu-Nb-Sn ternary phase diagram at 675°C [26], the reaction routes for the various types of Nb3Sn composites have also been indicated.

Fig. 7. Grain size vs reaction temperature for Tube conductors

Fig. 5. Reaction route to A15 for Tube conductors. (a) Initial NbSn2 formation, (b) Nb6Sn5 formation, (c) and (d) initial fine grain A15 formation, (e) conversion of the Nb6Sn5 to coarse grain A15, and (f) final reacted microstructure.

CSMM also is investigating Bc2 and high field Jc maximization in RIT conductors (in conjunction with Global R&D). In this case the Ti is known to increase electron scattering, reducing the coherence length and increasing Bc2. We are investigating the optimization of Ti dopant level, as seen in Figures 8 and 9.

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