Approach from temperature measurement to trapped field enhancement in HTSC bulks by pulse field magnetizing

Abstract The time dependences of the temperature rise Δ T ( t ) and the magnetization M ( t ) on the surface of the cryo-cooled SmBaCuO bulk superconductor have been investigated during the five successive magnetic pulse applications (No1–No5) of equal strength ranging from B ex  = 3.83–6.07 T. The pinning loss ( Q p ) is estimated by the hysteresis loss Q MH obtained by the M vs. applied field μ 0 H a curve and the viscous loss ( Q v ) is estimated by subtracting Q MH from the total Q which is estimated using the maximum temperature rise Δ T max and the specific heat C . For the first pulse (No1) application, Q p is a main origin of the heat generation and Q v is dominant for the No5 pulse. The temperature measurements combined with the measurements of the M – μ 0 H a curve have been proved to give us the valuable information as for the enhancement of the trapped field by PFM.

[1]  K. Tanabe,et al.  Advances in superconductivity XII : proceedings of the 12th International Symposium on Superconductivity (ISS '99), October 17-19, 1999, Morioka , 2000 .

[2]  K. Yokoyama,et al.  Temperature rise in an Sm-based bulk superconductor after applying iterative pulse fields , 2004 .

[3]  M. Yoshikawa,et al.  PULSED-FIELD MAGNETIZATION APPLIED TO HIGH-Tc SUPERCONDUCTORS , 1998 .

[4]  R. Koch,et al.  Pulsed magnetization of HTS bulk parts at T<77 K , 2000 .

[5]  H. Fujishiro,et al.  Thermal conductivity, thermal diffusivity and thermoelectric power of Sm-based bulk superconductors , 2002 .

[6]  T. Naito,et al.  Simultaneous Measurement of Thermal Diffusivity and Conductivity Applied to Bi-2223 Ceramic Superconductors , 1994 .

[7]  Time evolution and spatial distribution of temperature in YBCO bulk superconductor after pulse field magnetizing , 2003 .

[8]  Andrew G. Glen,et al.  APPL , 2001 .

[9]  K. Yokoyama,et al.  Generated heat during pulse field magnetizing for REBaCuO (RE = Gd, Sm, Y) bulk superconductors with different pinning abilities , 2004 .

[10]  S. Nagaya,et al.  Crystal structure and magnetic properties of melt-processed Sm1+2xBa2+xCu3+xOy superconductors , 2001 .

[11]  H. Hayashi,et al.  Study on a mobile-type magnetic separator applying high-Tc bulk superconductors , 2003 .

[12]  H. Ikuta,et al.  Performance of the magnetron sputtering apparatus equipped with 60 mm superconducting bulk magnet , 2003 .

[13]  T. Oka,et al.  Temperature measurement of RE123 bulk superconductors on magnetizing process , 2004 .