CLASSE NEWS | 16 Feb 2010
Cornell's prototype ERL injector cryomodule had to be completely dismantled for the following improvements:
1. the Q0 of the superconducting two cell cavities was only approximately 4*109, instead of the anticipated 2*1010. Cavities were therefore cleaned with high-pressure water, and some by buffered chemical polishing.
2. the 6 higher-order mode absorbers had been shown to charge up during electron-beam operation, leading to unintended deflections of the beam. These absorbers therefore had to be simplified, so they do not expose chargeable surfaces to the beam. Furthermore, their design was changed so strong tensions are avoided under cool down. Improving this cryomodule has been a large effort at the SRF laboratory and has taken approximately 4.5 months. However, on Monday February 8, 2010, the complete accelerating module has been moved from the SRF group to the accelerator test area in Wilson laboratory where it will accelerate electron beam about one month later.
Improved ERL injector cryomodule completed by the SRF group
ERL injector cryomodule (click for enlarged view).
1. the Q0 of the superconducting two cell cavities was only approximately 4*109, instead of the anticipated 2*1010. Cavities were therefore cleaned with high-pressure water, and some by buffered chemical polishing.
2. the 6 higher-order mode absorbers had been shown to charge up during electron-beam operation, leading to unintended deflections of the beam. These absorbers therefore had to be simplified, so they do not expose chargeable surfaces to the beam. Furthermore, their design was changed so strong tensions are avoided under cool down. Improving this cryomodule has been a large effort at the SRF laboratory and has taken approximately 4.5 months. However, on Monday February 8, 2010, the complete accelerating module has been moved from the SRF group to the accelerator test area in Wilson laboratory where it will accelerate electron beam about one month later.