Next Meeting

Date: June 24, 1997

Time: 3:00 - 4:00

Place: Test Lab Conference Room

Attendees

C. Bohn, J. Bennett, D. Kehne, G. Neil, P. Piot, C. Sinclair, K. Jordan

Addenda/Errata to Previous Minutes

• None.

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

• D. Kehne presented his results on longitudinal beam diagnostics of ITS gun. His measurements covered bunch charges of 10, 60, and 135 pC. The drive laser was unstable during the high- bunch-charge measurements, and this generated uncertainties in some of his data. For example, at 135 pC, there was considerable jitter in the energy spread. Moreover, there was a discrepancy between measurements of quantum efficiency and output current. This lead to an uncertainty in bunch-charge measurements at 60 pC; they could in fact have been 40 pC.

• One qualitative feature Dave observed at high bunch charges was a hollow longitudinal density profile, one that showed clumping at the head and tail of the bunch. This observation correlates with PARMELA predictions, at least qualitatively, and therefore was attributed to space charge. However, there remains a question concerning the sensitivity of the density profile with respect to the solenoid setting.

• In summary, Dave's experiment has been coming along well and should lead to a solid publication. To complete it, he estimated the need to do two more 10-hour runs, during which he would repeat the 60 and 135 pC measurements. As a result, the plans for the gun are to do a 48-hour run during Tuesday through Thursday to assess the effect of dark current on quantum efficiency, and then turn the gun over to Dave. He will then make a new cathode Thursday afternoon and run through the weekend. The plan remains to begin dismantling the gun on Monday, 23 June, to prepare for moving it to the FEL Facility, but all agreed to pronounce this date as tentative pending Dave's findings. He will apprise us not later than Monday morning whether to proceed. We all encouraged him not to hesitate to ask for assistance.

• none

Action Items
------------

• none.

   
Action Priority  Items (assigned)

----------------------------------


A-15   1  Commissioning Procedure                       Legg, Krafft
5/16/96
A-19   0  Web Documentation                                             weekly
A-24  1,2 Beam loss                                     Bohn
A-30   1  Burnthrough/Conflat Expansion      `1c                                                                                                                                             Denard, Kloppel
A-34   2  Consistent Linac phasing plan                 Yunn
A-42   2  2nd gun for long term tests			Bohn		10/1/96
A-44  1,2 Start Rui on emittance code                   Bohn
8/13/96
A-47   1  OTR beam interaction number by 		Denard		9/11
A-55   1  Laser Diagnostic Proc				Benson		11/1/96

Action Items (pending)
------------

P-05  1   Devise fine-tuning procedure for buncher gradient		Krafft/Kehne
P-08 1,2  How do we change energy? What is the energy range?		Benson
P-14  1   How is the gun/laser operated?				Benson
P-15      Discussion on robustness of controls				Legg
P-19  2   Consistent linac/bunching phase sets				Yunn
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
P-30  2   Tracking including realistic wiggler fields			Douglas
P-37  1   42 MeV dump design and interlocking				Wiseman

Agenda for Next Meeting
-----------------------

                Item                              Person Responsible     Time
                ----                              ------------------     ----
    *	Review agenda/corrections to minutes	        Legg	         5 min.
    *	Latest ITS experimental results			Kehne	        15 min
    *   Latest simulation results			Yunn		15 min
    *   Update on Happek device, test plans             Piot, Jordan    15 min
    *   New issues					All		 5 min	
    *	Agenda for next meeting		                All		 5 min.