Minutes of FEL Commissioning Meeting
March 25, 1996
Next Meeting:
- Date: April 2, 1996
- Time: 2:00 **** Please note (and complain about, if need be) time
- Place: MCC Room 101
Attendees:
C. Bohn, G. Niel, R. Legg and K. Jordan
Items of Discussion
The layout of the chicanes around the optical cavity changed again -
an interference with one of the transfer lines and the chicane forced
the change. This change will require a redesign of the lattice acco
rding to Dave Douglas and precipitated his absence.
Review Action Items
- Court did get the drawing revised and had it available for the meet
ing.
- Bob did have a plan for measuring the average currents in the 10 Me
V dumps using a ceramic break with a high external resistance (~100 k
ohms) and a precision electrometer/picoammeter. Using a mechanical r
f switch several dumps could share the same precision meter. He also
had drawings for a one turn, ferrite loaded current transformer, but
Kevin pointed out that by simply installing a second low impedance (
50 ohms), ceramic break direct readings of the beam current could be
achieved. It was agreed that using the second ceramic break was much
preferable tp the current transformer. Bob still needs to show plac
ement of the breaks in the 10 MeV dump.
- The path length check for recirculation will use the OTR after the
second arc and be checked the first time by looking at the transient
loading signal on the GASK for the first cavity in the module.
The major item for discussion was adding a fourth 42 MeV dump after t
he second arc. It was decided that this was necessary to measure bea
m properties prior to trying energy recovery. Court redlined the lay
out drawing to add the dump.
Actions
- Still need an impedance layout for the wiggler area (Niel)
- Do we need to bunch after the module?
We only need 35 amps to lase. Do we want to bunch?
- Reduce the M56 in the optical chicanes to less than 30 cm. (Douglas)
- Commisioning Procedure (Legg)
Pending action items will be dealt with after the new design is done.
Agenda for Next Meeting
- Review Agenda
- New drawing
- New lattice
- Agenda for next meeting