Speaker
Description
The combination of mid-T and subsequent low temperature heat treatments has been investigated as a means of improving SRF cavity performance [1]. These treatment combinations can retain high quality factors of up to 4·1010 obtained after mid-T treatment while enabling accelerating gradients up to 40 MV/m. Mid-T heat treatments are well known to increase the flux trapping sensitivity [2], prompting further investigation of the magnetic behavior around the superconducting transition.
For this purpose, the B-mapping system at DESY [3] has been improved. The system enables spatially resolved measurements of the magnetic field around 1.3 GHz single-cell SRF cavities. Recent upgrades of the control, acquisition, and data-analysis software and firmware enable more systematic studies of magnetic flux expulsion and trapping around the superconducting transition.