Qs. Shu et al., HIGHEST PERFORMANCE OF TESLA 9-CELL SUPERCONDUCTING RF CAVITIES BY OVERCOMING QUENCHES IN SUPERFLUID LHE, IEEE transactions on applied superconductivity, 7(2), 1997, pp. 371-374
Accelerating gradients Eacc = 26 MV/m with a world record Q of 3 x 10(
10) in 9-cell TESLA superconducting RF (SRF) cavities have been reache
d in CW and pulsed RF modes. On the way to reaching the excellent perf
ormance, we experimentally characterized quench natures (most serious
obstacle to higher gradients), investigated the Kapitza conduction and
boiling heat transfer between cavities and LHe II, and studied the qu
ench behaviors both in He II and normal LHe. Finally, we discuss the p
ossibilities of further greatly raising the accelerating gradients to
50-100 MV/m by use of Nb3Sn and some HTc superconducting materials.