[Hallc_running] Hall C laser
benesch at jlab.org
Tue Mar 17 14:50:48 EDT 2020
In the hope of reducing activation in CEBAF, based on Tiefenback's slit
reduction test and the chopper viewer image, the B Team has decided to
have CIS swap the B and C laser seeds on Thursday morning. The laser
seeds are upstairs and fed to the downstairs amps via fiber so this
should be an easy change. This will affect A and D beam delivery.
We'll see what it does to C when CW beam is restored. We'll learn
whether it screws up B beam Friday when that hall returns so we can back
out if necessary. It is expected that, as with Mike's test, the narrow
B slit will eliminate consequences of the long pulse for B.
If it works, A2 interception will remain stable, arc BLMs will be
quieter, and the X shoulder on the C beam at 3H07 harps will be gone.
After discussion, my proposal to change C beam optics was cancelled.
More information about the Hallc_running