Next Meeting

Date: May 28, 1996

Time: 3:00 - 4:00

Place: Test Lab Conference Room

Attendees

D. Douglas, B. Dillon-Townes, G. Neil, C. Bohn, S. Benson, D. Kehne, and G. Krafft

Items of Discussion

• There were two changes to the minutes from last meeting. Both C. Sinclair and S. Benson reported that I got the thing to be shielded in the front end wrong last week. In fact the device in question is the first bellows downstream of the light box. For mechanical reasons associated with the gun, it is preferable to leave this bellows unshielded. Getting this calculated still seems problematical. Next, Charlie also mentioned that the photo-emission in the gun by light background is not damaging, per se. It's just that one tends not to have control over where emitted electrons go, and they tend to cause problems like increased desorbtion, etc. He also mentioned that he was dubious about filtering the problem away, as suggested in the May 14 meeting. I forwarded his e-mail to Benson.
• There was no wide BPM meeting this week. We will try again next week.
• There were additional meetings on the wiggler diagnostics. The meetings are converging on specifications on wiggler OTRs. Preliminary work requires 30 mum resolution with 50 mum reprodicibility. A final plan will be available at the time of the workshop.

New Items

There were no new items discussed this week.

The lion's share of the meeting consisted of going through the current active task list in order to get revised dates asigned to items. The details are outlined below.

Finally, Krafft distributed a preliminary documentation hierarchy for people to think about. He and Jordan took the suggestions from last week, particularly that the system be tied in with the WBS structure, and added as much as they could think of as far as topics are concerned. Any additional topics or categories that should be added should be sent to krafft by e-mail. Probably it is best that individuals not try to get changes made individually, but the changes should be accumulated over several weeks and a new revision made. This will minimize the effort of the user liason people who are setting this up for us, helping to ensure that we don't overstay our welcome.

Action Items

A-01 No specific changes indicated. Douglas intends to make some changes however.

A-02 Agreed to report 6/4/96

A-03 No documentation confirmation as of 4/9/96.

A-05,06,07,10 Douglas and Krafft will discuss appropriate time table off-line. There are probably other additions to the optics list that will occur.

A-08 A good resolution of this problem was not forthcoming. Bohn will call Neuffer and obtain his longitudinal simulation code. Some combination of Douglas, Neil, and Merminga will run this code, DIMAD, and do analytic estimates to obtain the final baseline phases for the FEL. Lia was volunteered to document the results. We'll discuss a due date in the next few weeks.

A-11 Krafft will try to report something in two weeks.

A-15 The following "plan to produce the plan" was agreed to. First B. Legg would revise the old commissioning plan to be consistent with the FEL design. Second, the preliminary plan will be posted, and revised as appropriate. Finally, the detailed diagnostic analysis will be done based on the steps in the plan. It is perhaps significant that Legg did not attend the meeting. It seems a high priority to get going on this as final diagnostics plans cannot occur until this step is complete. We would like to have at least a list of procedures done by mid-june.

A-19 We hope to have a preliminary version of the documentation tree (hierarchy) posted next week. Please take pot shots at it as appropriate.

A-21 Jordan agreed to present a plan for diagnostics reviews on 6/11/96.

Finally, it was reported that there were vacuum problems in the gun again on achieving 390 kV. Stay tuned.

Also, new FEL cost accounts should be coming soon as the "money is here".

First Cut List of Commissioning Tasks

The following list was started for commissioning the Injector Test Stand by D. Kehne and G. Krafft. It is only a first cut and should be added to and modified through e-mail to G. Krafft. The list is a partial answer to the question: what does it mean for the Injector Test Stand to be done?

C-1     RF gradients verified
C-2     Operational RF phases determined
C-3     Drifts (of phases if like main machine) quantified
C-4     Gun current verified/operational procedure complete
C-5     Beam jitters determined
C-6     Cryounit Focussing/Convergence determined
C-7     High power CW beam is delivered for ``awhile''
C-8     Cathode lifetime studied
C-9     Engwall/Kehne studies on gun transverse/longitudinal emittance complete
C-10    PARMELA ``verified''

After the move to the FEL building the following tasks must be completed to prepare the beam for injection into the linac.

C-11    Transverse phase space at injection verified
C-12    E-beam matched at injection point
C-13    Longitudinal phase space verified
C-14    Longitudinal tilt checked at injection
C-15    Above determined at high power

Action Items (assigned)

A-01	Update Drawing                                Bohn                weekly
A-02    Viewer light photocurrent                     Benson, Jordan     6/04/96
A-03    Stray fields in test stand                    Legg              complete
A-04    Unit gradient precision                       Bohn, Liu
A-05    Injector energy precision                     Douglas
A-06    10 MeV dump optics                            Douglas
A-07    Bypass optics                                 Douglas
A-08    M56/RF phasing and beam load issues           Neil, Douglas, Liu
A-09    Dump Instrumentation                          Legg               6/04/96
A-10    Back leg diagnostic placement                 Douglas
A-11   	Multifrequency CSR Measurements               Krafft             6/04/96
A-12    How should the path length be checked?        Krafft, Jordan     6/11/96
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/Assess Far. Cup   Legg
A-17    4-Channel BPM on the IRFEL                    Bohn, Denard
A-18    Trombones                                     Douglas, Krafft
A-19    Web Documentation                             Krafft              weekly
A-20    10->42 MeV dump                               Biallas
A-21    Diagnostics reviews                           Jordan             6/11/96 

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-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    Discussion on robustness of controls??????
P-16    Injector diagnostics in the main machine
P-17    Gang of power supply for backleg quads
         (must include emittance meas. capability)
P-18    Technote by Yunn summarizing machine impedance
P-19    Consistent linac/bunching phase sets
P-20    Lock plans (who in particular)
P-21    Save/restore plans
P-22    FSD plans
P-23    Transverse Effects in CSR
P-24    FEL Commissioning review
P-25    RF control sensitivities/Microphonics Diff for FEL/Pathlength effect
P-26    What if studies
P-27    Plan to measure beam loss
P-28    Scrapers: Where and How?
P-29    FEL/linac interaction
P-30    Tracking including realistic wiggler fields
P-31    What drives the vacuum spec.
P-32    Are two sextupole families enough to tune M56
P-33    Is path length feedback needed?
P-35    Coordinated ITS beam running/SRF commissioning plan
P-36    Beam power robust BPMs
P-37    42 MeV dump design and interlocking

Agenda for Next Meeting

           Item                           Person Responsible     Time
           ----                           ------------------     ----
*   Review agenda/corrections to minutes         Krafft	         5 min.
*   New drawing                                   Bohn           5 min.
*   New issues
         BPM Burnthrough Calculations
         Coupler Kick Measurements
         SLM cameras and plans

*   Web documentation                            Krafft          5 min.
*   Pending Task List Discussions                 All           30 min.
*   Agenda for next meeting	                  All		 5 min.