Next Meeting

Date: September 9, 1997

Time: 3:00 - 4:00

Place: Bldg 89, Large Conference Room

Attendees

R. Legg, G. Neil, J. Bennett, C.L.Bohn, Q.S.Shu, G.A.Krafft, L. Merminga, P.Piot

Addenda/Errata to Previous Minutes

The DW's are still being looked at for the cause of the 2E-4 integrated field flatness error, but at least the first four will be released for installation. The effect is not considered a show stopper, but we want to insure the magnets can be modeled without surprises.

Items of Discussion
-----------------

• The injector setup procedure was described by legg. The setup parallels the nuclear physics machine setup with a threading procedure and use of transient phasing and dispersed viewers to crest cavities and set gradients. The FEL injector however, runs the second cryounit cavity 27.5 degrees off crest and uses a lower injection energy into the unit. The other difficulty is that the cavities gradient and phase loops will not be characterized initially and a fine setup procedure must make use of the existing diagnostics to set the buncher and two cryounit cavities' phase and gradients to the 1 degree and 2 percent precision required from the +/-5 degrees derived from transient phasing and the +/-10% derived from the SRF/RF commisioning of the rf couplers. To decide which parameters to tune against, PARMELA simulations of the injector were made while varying the six phase and gradient variables and plotting the beam parameters at the downstream diagnostics. The data is shown in the table below:

  
  buncher Amp     -10%    -4%     0       4%      10%
  Energy, MeV     9.09    9.09    9.09    9.09    9.09
  dp/p, keV       92      76      73      76      92
  Emit X, mm-mr   5.29    5.24    5.44    6       7.48
  Sigma X, mm     1.79    1.88    1.95    2.02    2.1
  Bunchlength     3.2     3.2     3.3     3.5     4.2
  
  0F01-1, phase   -5      -2      0       2       5
  Energy, MeV     9.24    9.15    9.09    9.03    8.93
  dp/p, keV       60      67      73      80      90.4
  Alpha, X        -1      -0.1    0.3     0.7     0.94
  Emit X, mm-mr   6.03    5.64    5.44    5.27    5.04
  Sigma X, mm     2.76    2.3     1.95    1.64    1.21
  Bunchlength     2.9     3.1     3.3     3.45    3.7
  
  0F01-1, Grad    -10%    -4%     0       4%      10%
  Energy, MeV     8.83    8.95    9.04    9.12    9.03
  dp/p, keV       116     108     102     97      76
  Emit X, mm-mr   7.48    7.42    7.4     7.3     7.3
  Sigma X, mm     2.39    2.26    2.21    2.13    1.95
  Bunchlength     4.28    4.17    4.05    4       3.9
  
  0F01-2, phase   -5      -2      0       2       5
  Energy, MeV             8.95    9.04    9.118
  dp/p, keV               157     102     94
  Emit X, mm-mr           7.4     7.4     7.4
  Sigma X, mm             2.24    2.21    2.18
  Bunchlength             4       4       4
  
  0F01-2, Grad    -10%    -4%     0       4%      10%
  Energy, MeV     8.83    8.95    9.04    9.12    9.24
  dp/p, keV       93      98      102     106     111
  Emit X, mm-mr   7.3     7.4     7.4     7.4     7.4
  Sigma X, mm     2.3     2.24    2.21    2.18    2.13
  Bunchlength     4       4       4       4       4
  

  The draft for the injector setup procedure will be out by next Tuesday.

• Bob said that the commissioning schedule was going to be put on the web in the same format as CEBAF's by Gordon once he gives Gordon the information. Geoff asked if Bob planned on keeping the day to day schedule up to date himself normally. The answer was yes, but we're looking at getting Gordon or possibly Dick Walker to take over the scheudles once they have more time.

• None.

Action Items

• High level apps for diagnostics meeting Friday, Sept 5 in bldg. 89 at 9 AM. (LEGG)

Action Priority  Items (assigned)

A-15   1   Commissioning Procedure                 Legg          7/16/97
A-19   0   Web Documentation                                     weekly
A-34   2   Consistent Linac phasing plan           Yunn
A-44   1,2 Start Rui, Jinhu? on emittance code     Douglas       8/13/97


Action Items (pending)

P-05  1    Devise fine-tuning procedure for buncher gradient        Legg
P-08  1,2  How do we change energy? What is the energy range?       Benson
P-20  1    Lock plans (who in particular)                           Johannes?
P-21  1    Save/restore plans                                       Benesch
P-25  1,2  RF control sensitivities/                                Merminga
           Microphonics Diff for FEL/
           Pathlength effect
P-29  2    FEL/linac interaction                                    Merminga


Agenda for Next Meeting

           Item                              Person Responsible     Time
           ----                              ------------------     -----
*  Review agenda/corrections to minutes          Legg               5 min.
*  Rf integration update                         Merminga          15 min
*  Discussion                                    ALL               20 min
*  New issues                                    all               10 min
*  Agenda for next meeting                       All                5 min.