Next Meeting

Date: April 30, 1996

Time: 3:00 - 4:00

Place: Test Lab Conference Room

Attendees

K. Jordan, J. Denard, C. Bohn, D. Douglas, L. Merminga, D. Kehne, and G. Krafft

Items of Discussion

There were no changes to the minutes. A single organizational issue was discussed. The meeting minutes are now on the WEB. To get to them from the CEBAF home page select FEL and Status. All future minutes will be posted. Thanks to K. Jordan. Just a reminder that we'll have to discus organizing other contributions in the future.

Other contributions can be made presently by submitting them to jenni@cebaf.gov by e-mail.

Action Items

A-01 No major updates for the main machine were proposed. A vacuum valving scheme with valves at the four corners of the machine and with valves to isolate the dumps (where burn-through is most likely) was dis- cussed and generally approved of.

A-03 No documentation confirmation as of 4/16/96.

A-04Still no progress. The question was reposed, perhaps more clearly as, given that the gradients in the two unit cavities are different, what is the largest difference permissible, where small beam loss or small beam properties degradation are still achieved.

A-05Dave investigated the acceptance limit of the reinjection. He believes that we should be able to go down to 28 MeV without much trouble.

A-17 Denard reported on the requirements discussed at the separate meeting on this topic to the whole group. There was general agreement with the presentation, except for the update rate. Several people wanted a faster rate. A question arose concerning the responsibility for getting the locks done, and it was agreed that there was no-one looking into this, a situation that should be rectified. There was also some discussion about when the locks were needed. It was agreed that Denard would distribute the requirements pages, and comments should be made back to Krafft through e-mail. It was also mentioned that there might have to be a save done of the current of the setting if the 4-channel BPMs are used. So save/restore has to save the current.

A-19 Kehne gave a talk on the experiment plans and specifications. He stated that the doubled quads and QBs were OK. There were no comments disagreeing with what he has done. The issue of the final spec of the 10 MeV dipole magnet came up again. He complained that getting a flip viewer in was an issue. Kehne was encouraged to coordinate with Legg and Dillon-Townes to get this in the system.

Lia gave her practice run, which was approved of. She investigated the routine startup procedure and found that energy offsets less than 0.1% and phase shifts under 0.3 deg were generated. The outstanding issue to be resolved is the time delay generated by the energy slew when the FEL starts. Bohn reported that Liu had completed simulations through the wiggler. Also, the wiggler impedance estimate has been refined.

Action Items (assigned)

A-01	Update Drawing                         Bohn               4/16/96
A-03    Stray fields in test stand             Legg              complete
A-04    Unit gradient precision                Bohn, Liu          4/16/96
A-05    Injector energy precision              Douglas            4/09/96
A-06    10 MeV dump optics                     Douglas            5/14/96
A-07    Bypass optics                          Douglas            4/30/96
A-08    M56/RF phasing and beam load issues    Neil, Douglas, Liu
A-09    Dump Instrumentation                   Legg               5/23/96
A-10    Back leg diagnostic placement          Douglas            5/30/96
A-11   	Multifrequency CSR Measurements        Krafft             4/30/96
A-12    How should the path length be checked? Krafft, Jordan     4/30/96
A-13    Impedance Layout for Wiggler           Yunn, Neil        complete
A-14    Reduce M56 to under 30 cm              Douglas           complete
A-15    Commissioning Procedure                Legg, Krafft       5/16/96
A-16    Average Current Measurement            Legg
A-17    4-Channel BPM on the IRFEL             Bohn, Denard       4/30/96
A-18    Trombones                              Douglas, Krafft    4/09/96
A-19    Experiment Plans, 10 MeV line, etc.    Kehne              4/09/96
A-20	Flip viewer			       Kehne		  5/07/96		

Action Items (pending)

P-01    Determine Beam Pulse structure for setup
P-02    Laser phase modulator
P-03    Slit emittance measurement
P-04    Is an energy compression scheme needed?
P-05    Devise fine-tuning procedure for buncher gradient
P-06    Web Documentation
P-07    Diagnostics "Freeze"
P-08    How do we change energy? What is the energy range?
P-09    Do we need bunching after the module
P-10    Will the SLM monitor work to center the large beam
P-11    Calculate from Hall C data how much scatter the BPMs can take
P-12    FEL/OTR interaction question
P-13    Do we have sufficient diagnostics for emittance degradation measurements
P-14    How is the gun/laser operated?
P-15    Injector diagnostics in the main machine
P-16    Gang of power supply for backleg quads
P-17    Technote by Yunn summarizing machine impedance
P-17    Consistent linac/bunching phase sets
P-19    Lock plans (who in particular)
P-20    Save/restore plans
P-21    FSD plans

Agenda for Next Meeting

          Item                              Person Responsible     Time
          ----                              ------------------     ----
    *   Review agenda                                    Krafft          5 min.
    *   Corrections to minutes from last meeting          All            5 min.
    *   New drawing                                       Bohn           5 min.
    *   BPM requirements                                  Denard        20 min.
    *   Review task lists                                Krafft         30 min.
    *   Agenda for next meeting                           All            5 min.