The critical currents of MgB_2 tapes after the shock-wave plasma influence through the protective screens with different thermal characteristics

摘要

The report presents the researches of the current-carrying characteristics of MgB2 tapes after exposure to shock-wave action through the protective screens with different thermal characteristics. It was used molybdenum, titanium, iron and copper. To implement the shock wave impact, a plasma focus (PF) type setup was used. Current-voltage characteristics (CVC) of the tapes in the initial state and after shock-wave action (SW) through the protective screens are presented. Dependences of critical currents from magnetic field value are measured in the transverse magnetic fields from 0.3 to 6.0 T at the temperature of 4.2 K. The studies performed showed a noticeable change in the critical currents according to the screens material used. The largest increase in J_c (more than 2 times up to 850 A in transverse and longitudinal magnetic fields up to 1 T) was achieved in case of titanium screen.