Speaker
Description
The test result of the newly developed seamless cavity is compared with the series cavities already installed and operated in the cryomodules.
Slow and uniform cool down has been preferred by the series cavities; thus optimized cool-down procedure has achieved performance better than the nominal design.
The off-line test in a dedicated cryostat showed that the seamless cavity did not depend on the cooling down, and resulted in the best performance even without a special care during the cooling down.
Instead, this new cavity was relatively sensitive to the ambient magnetic field such as the earth field.
Comparison between series and seamless cavities will provide information about the thermodynamic environment inside the cryomodule during the RF commissioning 2018.
Also, in order to use the seamless cavity as a spare in the lower energy cryomodules, i.e. CM1 and CM2, a possible modification will be proposed by correcting the beam steering effect.
Finally, possible cavity designs for the low-beta section in Phase3 will be discussed.
