Reza's thoughts on bunchlength measurement at UITF
Checking the bunch length system with 200keV beam and No choppers
Requirements: At minimum we need the following
- - Beam through bunch length cavity
- - More than 5uA tune beam
- - 200 keV energy or higher
- - Bunch length less than 30 degree of 1497 (typical low current beam at the gun)
- ) With choppers and buncher off, thread the 200 keV beam from gun up through the bunch length cavity.
- ) Setup more than 5uA tune beam (preferably to a beam dump or Fcup).
- ) Check the bunch length system by answering the following questions
- ) Do you see the bunch length output signal? If not stop and investigate.
- ) Does the bunch length signal change as the gun laser phase changes (multiples of 5 degrees, up to +/- 50 deg)? If not stop and investigate. Does the amount of change make sense?
- ) Does the bunch length signal changes as the 6 GHz reference signal phase is change (+/- 180 deg)? If not investigate.
- ) When all questions above have positive answer, the test is complete and system is checked for hardware.