Enhancement of total trapped fluxes on φ65mm GdBaCuO bulk by multi-pulse techniques

Abstract

We have investigated the total trapped flux Φ T (z) on the φ65 mm GdBaCuO superconducting bulk as a function of distance z from the bulk surface magnetized by a successive pulse field application (SPA) with identical magnitude and subsequent iterative pulsed-field magnetization method with reducing the amplitude (IMRA) at various temperatures T s . The Φ T (z) value was enhanced by the IMRA process and reached 5.02 mWb on the bulk surface at T s =40 K, which was about 1.7 times larger than that at the end of SPA. The Φ T (4 mm) value at 40 K by the SPA+IMRA method was as high as Φ T FC (4 mm) by field cooled magnetization under B ex =3 T at 48 K. The IMRA method is quite effective to enhance the Φ T value for large superconducting bulks.(125 words) ACCEPTED MANUSCRIPT2

Estimation of temperature rise from trapped field gradient on superconducting bulk magnetized by multi-pulse technique

“…It was 2.2 times larger than that on the 45 mm bulk by the MMPSC + IMRA method ( P T = 2.51 mWb) [14]. The P T (4 mm) value (=4.1 mWb) at 40 K using the SPA + IMRA method was as high as the FC T (4 mm) value (=4.44 mWb) obtained using FCM under B ex = 3 T at 48 K [13].…”

“…As a result, the J c value is higher than with condition A. However, the maximum P T (4 mm) value of 4.0 mWb was realized for the subsequent pulsed application of condition A, which was as high as FC T (4 mm) by FCM under B ex = 3 T at 48 K [13]. The P T (0.5 mm) values for condition B are also shown in the figure, which are about 1.33 times larger than P T (4 mm).…”

“…The maximum trapped field on the 65 mm bulk was as low as B P T = 1.3 T by SPA and B P T = 3.0 T by MMPSC at 40 K, which was smaller than those on the 45 mm bulk because of the lower J c . However, the P T value for a large bulk can be enhanced easily using the IMRA method; the P T (0.5 mm) value, which was measured at z = 0.5 mm above the bulk surface, was as high as 5.05 mWb on the 65 mm bulk at T s = 40 K using the SPA + IMRA method, which was about 1.7 times larger than that obtained using the SPA method ( P T = 2.9 mWb) [13]. It was 2.2 times larger than that on the 45 mm bulk by the MMPSC + IMRA method ( P T = 2.51 mWb) [14].…”

“…Using the previous results, the respective temperature rise values were estimated as 4 K at T F = 50 K, 2 K at 60 K and 1 K at 70 K, respectively. Figures 3(a) and (b) respectively portray the pulse number dependence of the cross section of the trapped field profile B P T (0.5 mm) and B P T (4 mm) for 'condition A' (T s = 40 K, B1 = 6.6 T) [13]. In figure 3(a), for the no.…”

“…FCM: field-cooled magnetization.) Method 65 mm bulk [11,13] (at 40 K) 45 mm bulk [14] (at 30 K) useful for applications such as electric motors/generators and sputtering cathodes. We have investigated the trapped field characteristics on the 65 mm GdBaCuO bulk by successive pulsed-field application (SPA) and the MMPSC method [11,12].…”