Free Electron Laser Commissioning Meeting

Friday, 9 Jan 98
Recorder: C. Bohn

Next Meeting


Date: 16 Jan 98
Time: 0830-0930
Place: FEL Facility Break Room

Agenda for Next Meeting


Item Person Responsible Time ---- ------------------ -------- Progress Report on Commissioning Bohn/All 30 min FEL Inputs for SWIS Bohn/All 10 min New Issues All 5 min Agenda for next week All 5 min

This Week's Attendees


J. Bennett, S. Benson, J. Bisognano, C. Bohn, D. Douglas, F. Dylla, D. Engwall, A. Hofler, G. Krafft, R. Legg, L. Merminga, G. Neil, P. Piot, J. Preble, Q.-S. Shu

Closed Action Items


There were no open action items from last meeting.

Items of Discussion


We outlined key top-level tasks that need to be accomplished prior to resuming commissioning with electron beam for which the planned date is 26 Jan 98. All of the key tasks are being worked, and they are:

        Task                                                    Principal
        ------                                                  ----------
        Prepare for Commissioning from MCC                      Bohn
        Align Injector Components                               Legg
        Complete MPS for First Light                            Jordan
        Complete Field Maps for First-Light Magnets             Douglas
        Finish Configuring First-Light BPMs                     Krafft
        Finish and Install Bunch-Length Monitors                Jordan

FEL Commissioning Meetings during Jan 98 will be partly dedicated to monitoring progress on these tasks.

In addition, there is a punch list of "installation" activities for the month that was put together during the 6 Jan 98 FEL Coordination Meeting. R. Walker compiled the list, and it is reproduced below for the convenience of the reader (and incorporates, as appropriate, the tasks listed above):

                                Task List for FEL Group
                                ------------------------

Install pellicles in optical cavity.                              M. Shinn
Install collimator for the FEL optical transport.                 M. Shinn
Complete installation of optical cavity.                          M. Shinn
Terminate cables for optical cavity and wiggler.                  K. Jordan
Install raster magnets and control cables for dumps.              K. Jordan
Install 2 work stations and video system in MCC.                  K. Jordan
Get ready for commissioning from the MCC.                         C. Bohn
Work on the Gun and bake.                                         R. Legg & 
                                                                  T. Siggins
Check for 8 KW klystrons for cryomodule.                          R. Walker
Install and test the MPS.                                         K. Jordan
Change windows on the cryounit.                                   J. Preble
Have M.O. reference oscillator returned.                          R. Walker
Track down vacuum leak in 2G dump line.                           K. Jordan
Upgrade RF software to fix bugs.                                  R. Walker
Commission magnet probes with EPICS.                              R. Terrell
Buy engine hoist for vault work.                                  K. Jordan
Install EO1.                                                      M. Shinn
Install grating over cryo lines and clean area.                   G. Biallas
Complete SF6 system.                                              R. Legg &
                                                                  T. Siggins
Test spare 50 KW klystron.                                        J. Fugitt
Install anchors for mirror cassettes.                             M. Shinn

Task List for Installation Group (as time and crews are available)
-----------------------------------------------
Install arc vacuum chambers.                    (3F & 5F)
Install arc magnets.                            (3F & 5F)
Install 2nd DV magnet.                          (5F)
Prepare for GEN hardware.                       (2G)
Install beam current cavity 0F06.               (0F)
Install air core corrector magnets.
Replace MDC valves with VAT valves.
Install insertable dumps.                       (4F & 5F)
Install crossovers over the beam line.          (4F)
Install the sextupoles and trim quads.
Provide cooling for trim card resistors.
Install the Happek stand by wiggler bench.      (2F)

L. Merminga summarized the status of rf commissioning of the cryounit and cryomodule. Closed-loop phase errors measured thus far are well within specification for both, although the cryounit is more noisy than the cryomodule for reasons not yet understood. The task list to complete rf measurements is as follows:

  1. Finish measurements of magnitude and frequency of microphonic noise, as well as gradient and phase stability without beam.
  2. Measure range, frequency-dependence, and hysteresis curves of the magnetostrictive tuners.
  3. Measure stability of control system as a function of cavity detuning, with the goal of avoiding cavity oscillations.
  4. Calibrate gradients in the cryounit and cryomodule with beam.

The commissioning tasks leading through the first (FEL) user experiment and their scheduling were discussed in depth, with the following result:

                Commissioning Tasks through First User Experiment
                -------------------------------------------------

Timing          Task
------          ----
1/28-1/30       Tune-up beam to injector dump (2 ľA, 9.6 MeV/c)
1/31-2/2        Tune-up beam to 1st-light dump (2 ľA, 38 MeV/c)
                        (check out MPS, BLM settings)
2/3-2/16        60 pC to injector dump, normalized emittance ~6 mm-mr (2
                ľA, 9.6 MeV/c)
                (interweave 1.1 mA runs to injector dump)
2/17-2/18       Install GEN target, ops suspended
2/19-2/21       Irradiate GEN swing/owl (2 ľA, 38 MeV/c), install day 2/22            Remove GEN target
2/23-3/15       60 pC to 1st-light dump, normalized emittance <20 mm-mr, bunch
                length ~1 ps (2 ľA, 38 MeV/c) (interweave 1.1 mA runs to 
                1st-light dump, look at cathode lifetime; spinoff: 1st CSR 
                test @ 2nd chicane with 60 pC)
3/16-3/27       Configure 1st-light electron beam (1.1 mA, 38 MeV/c)
3/28-31         Install wiggler, check out FEL systems
4/1-4/30        Lase @ >100 W
5/1             Party Time!!!
5/2             ARR Mini-Review (?)
5/2-5/31        Prepare laser beam for user experiment
6/1-6/15        Send laser beam to user lab
6/16-6/30       Do first user experiment

Three-shift operations will prevail throughout unless otherwise indicated. J. Bennett advised that some provision for an Accelerator Readiness Review is required prior to running a user experiment, and this is reflected above. J. Boyce should check into this and plan accordingly. We will fold in beam-dynamics studies through the first recirculation arc as time permits; in other words, these studies are a backup during this time frame.

Over the next two weeks Bohn will work with Legg and Walker to develop strawman shift assignments through 3/31, and G. Neil together with S. Benson will do likewise for the month of April, so we will have a 3-month manpower plan from which to line up people with appropriate advance notice.

New Issues


The indicated commissioning tasks require development of procedures for checking out the MPS and the BLM settings (assigned to K. Jordan), and an overall strategy for optimizing the electron-beam quality (Bohn will schedule first meeting for early next week).

New Action Items


Old Action Items


None.

Procedures in Work


First Light Setup

Emittance Growth from CSR

Thread Beam around Machine, Top-Level           Douglas, finalize 31 Jan 98
RF Stability during Energy Recovery             Merminga, 23 Jan 98
MPS/BLM Checkout for First Light                Jordan, 23 Jan 98