Free-Electron Laser Commissioning Meeting
Tuesday, Sept 16, 1997
Recorder: R. Legg
Next Meeting
- Date: Sept 23, 1997
- Place: Bldg 89, Large Conference Room
Attendees
R. Legg, G. Neil, C.L.Bohn, J. Bennett, D.Kehne, S. Benson
G.A.Krafft, D. Douglas, P.Piot, K. Jordan, B. Yunn, R. Li,
R. Walker, J Preble
Addenda/Errata to Previous Minutes
The Injector setup procedure is posted in ACROBAT format on the www at:
http://www.cebaf.gov/~legg/procedures/Injector_setup_proc.pdf
- We'll talk about this setup next week, so take a look.
- The Magnet Performance Integration Plan is now released as TN-97-034. It can be viewed on the www at the technote page of the FODOMAT
homepage.
(www.cebaf.gov/~douglas)
- B. Yunn re-checked the design for the lattice with respect to the
energy spread at the end of the injector and at the wiggler. The
values are 2.5e-3 in injector and 1e-3 at wiggler. The conclusion
was that, if the system works as designed, the momentum spreads at the
two spots are consistent.
Items of Discussion
----------------------
- D. Kehne gave a summary of his further analysis of the longitudinal
emittance data from the ITS. The charts for his talk will be posted
and a www address should appear in next Tuesday's minutes.
- The highlights were:
- - He suggests that there is an error in the measurement of the
bunch charge using the long pulse, high current setup with
the present picoammeters setup. The 135 pC case he says may have
been as high as 175 pC (!). This will bear watching in the FEL
installation.
- - The measured longitudinal emittance is about 44 keV-degrees with 175 pC
and the spec is 50 keV-degrees, although the measurement is
dominated by the error caused by the finite slit sizes.
- The question of how shifts will be covered for the Oct, Nov, and Dec
runs was discussed. After several pointed questions about the
schedule, Court and George agreed to the release of the latest
EXCEL version which is similar to the main machine's and uses a
template provided by G. Smith. The schedule is posted on the www at:
http://www.cebaf.gov/~legg/fel_schedule/.pdf
The associated task vs. PI's list is posted at:
http://www.cebaf.gov/~leff/fel_schedule/Task-PI_list.html
- This schedule only runs through Jan and at that time Gordon
will add three columns to the main machine schedule for the
FEL and it will look like just another hall for scheduling
purposes.
- The discussion degenerated at this point to concerns that
management had not yet secured agreement from groupleaders
and M7 for the use of the PIs, nor did it appear that
sufficient resources were approved to cover the shifts
which were planned. Court said that FEL and Division
management were presently engaged in talks concerning this
issue, but no comment was appropriate at the moment.
The comment was made that we should have a backup plan
rather than wait for management to make a decision. Legg
conceded that we would use a model like that used on the
ITS - we would sit down, look at the available bodies and
decide how much we could cover and who would cover which
shifts. Not the best of cases, but it should work.
New Issues
- S. Benson said DOE has made inquiries concerning a Mid and Far
IR device. He says there are questions concerning the beam
properties and transport that we should have for this system.
Interested parties should contact Steve Benson.
Action Items
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.
* Injector phasing setup Legg 20 min
* New issues all 10 min
* Agenda for next meeting All 5 min.