Next Meeting

Date: April 9, 1996

Time: 3:00 - 4:00

Place: Test Lab Conference Room

Attendees

K. Jordan, J. Denard (1st Half), C. Bohn, G. Neil, D. Douglas, R. Legg, D. Kehne, B. Dillon-Townes, S. Benson, and G. Krafft

Items of Discussion

We began by discussing two organizational issues. First, G. Krafft volunteered to produce and maintain two task lists, and "active item" list and a "pending" list. Active items will have a name assigned and a next report date. Pending items are items we know we have to get to, but aren't high enough in priority to deal with presently. The main body of the meeting should be to go through any active items due; reports to the group should be prepared before hand, with the goal of having enough information to close out the issue at the meeting. Krafft also presented the lists as to current items he has received so far (below). Any additions or better, subtractions, are encouraged. Communication of requests through e-mail is encouraged.

Next we discussed how documentation should be done. The goal is to have a central location where technical contributions, plans, drawings, etc. for the FEL will reside. It was agreed that it is a good idea to have the material computerized with the web in the future; we should try to draft a student to create and maintain the information. K. Jordan agreed to check into this. For the short term G. Neil maintains an FEL notebook, and documentary contributions should be forwarded to him. Finally, it was agreed that the type of documentation required (e.g. a technote, presentation slides, formal reports, or even papers!) will be discussed in this meeting, as the final step in closing an issue.

Action Items

The main body of the meeting consisted in systematically going through the

A-01 Main update was the addition of 4th dump. When the design has finally settled we will go through the drawing one last time to check that the diagnostics are OK.

A-02 The buncher gradient will be calibrated in the controls to within 20%. Thus the control setting will provide the first setting for buncher setup. It was agreed that the fine tuning for the buncher amplitude needs work; this item was added to the pending list.

A-03 Legg reported that the stray fields had been measured and found to be less than two Gauss, predominately vertical, and that such fields should not be much a hindrance in commissioning. He was asked to provide a summary report for the notebook.

A-04 As there is a new baseline design, a final answer on this issue was not given. Bohn agreed to talk to Liu about a simulation to get these issues resolved when the baseline converges. He thought that he could give a final report in two weeks.

A-05 Dave agreed to calculate the energy acceptance of the recirculation optics by next week.

A-06 Dave agreed to report on the 10 MeV dump optics on 5/14/96.

A-07 Dave agreed to report on the Bypass optics of 4/30/96.

A-08 The work on getting the M56 down below 30 cm in the chicanes is complete. There seems to be a lingering issue related to finalizing the bunching, including doing a complete simulation of the bunching, including the RF. Next meeting we will discus what needs to be done to get this resolved.

A-09 Legg reported that he's looked into current monitoring with K. Jordan, and they have come up with a plan involving a ceramic break. Such a system would have an absolute calibration of about 5%. Also his preliminary investigation led to several possibilities for IR cameras. He will give a complete 10 minute presentation in mid-May.

A-10 No report

A-11 Krafft has done some calculations on multifrequency monitors that he will report next week. He hopes to have a complete proposal by 4/30/96.

A-12 No report

A-13 Tentatively, Yunn will report next week on this issue.

A-15 A commissioning overview talk will be presented at the kick-off meeting in two weeks. Legg will give a five minute summary to this group on 5/16/96.

A-16 See A-09 above. Legg is looking at cross-calibrating the break monitor with a Faraday Cup. No convergence yet.

Three non-agenda items were discussed. J. Denard expressed the fact that he felt that the specifications for the IRFEL BPM electronics were not sufficiently precise to allow him to answer the question of whether the 4-channel electronics are useful for our application. Since a substantial potential cost might be saved by doing this, there was consensus that using the 4-channel monitors should be persued. This item also has aspects dealing with pending item P-01. below. A committee of C. Bohn, G. Neil, K. Jordan, and J. Denard was assigned to answer the question: Can we use the 4-channel electronics in the IRFEL? They will report back on progress next week.

It was confirmed by D. Douglas that, for the purposes of an emittance measurement after the wiggler, we should have the 5th OTR viewer in the wiggler region.

B. Dillon-Townes requested final inputs on the test stand beam line. Several items were added, and concern was expressed about the first viewer in the line not fitting. This will be resolved this week.

Action Items (assigned)

A-01	Update Drawing                            Bohn               4/09/96
A-02    Buncher gradient calibration              Neil                defer
A-03    Stray fields in test stand                Legg              complete
A-04    Unit gradient precision                   Bohn, Liu          4/16/96
A-05    Injector energy precision                 Douglas            4/09/96
A-06    10 MeV dump optics                        Douglas            5/14/96
A-07    Bypass optics                             Douglas            4/30/96
A-08    M56/RF phasing and beam load issues       Neil, Douglas, Liu
A-09    Dump Instrumentation                      Legg               5/23/96
A-10    Back leg diagnostic placement             Douglas            5/30/96
A-11   	Multifrequency CSR Measurements           Krafft             4/09/96
A-12    How should the path length be checked?    Krafft, Jordan     4/30/96
A-13    Impedance Layout for Wiggler              Yunn, Neil         4/09/96
A-14    Reduce M56 to under 30 cm                 Douglas           complete
A-15    Commissioning Procedure                   Legg, Krafft       5/16/96
A-16    Average Current Measurement               Legg
A-17    4-Channel BPM on the IRFEL                Bohn, Denard
A-18    Trombones                                 Douglas, Krafft    4/09/96
A-19    Experiment Plans, 10 MeV line, etc.       Kehne              4/09/96

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-06    Web Documentation
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?

Agenda for Next Meeting

                Item                            Person Responsible     Time
                ----                            ------------------     ----
*   Review agenda				      Krafft	      5 min.
*   Corrections to minutes from last meeting	      All 	      5 min.
*   New drawing                                       Bohn            10 min.
*   Optics issue (recirculator acceptance)            Douglas         10 min.
*   Multifrequency CSR	                              Krafft  	      10 min.
*   Wiggler Impedance                                 Neil, Yunn      10 min.
*   10 MeV Magnets and Experiment Plans               Kehne           10 min.
*   Tronbones                                         Douglas         5 min.
*   Agenda for next meeting		               All	      5 min.