AGENDA:

General Announcements

Action Items

Progress Toward the Milestones of the enclosed schedule:

NOTE: Meetings are held every Tuesday in CEBAF Center, Room #A110, at 11 a.m., unless otherwise notified.

NOTE: A reminder to all principals to submit a brief weekly progress to D. Gilchrist each Friday by noon

ATTENDEES: G. Biallas, S. Benson, C. Bohn, L. Dillon-Townes, D. Engwall, J. Fugitt, K. Hovater, K. Jordan, G. Krafft, R. Legg, G. Neil, M. Shinn, T. Siggins, C. Sinclair, R. Walker, M. Wiseman

General Announcements:

No dings on our latest safety inspection. Congratulations K. Jordan

Decisions/Comments:

Note that we intend to install the 10 MeV Beam Line while the Longitudinal experiment is running, starting in December. Get your apparatus ready.

Safety Action Items:

None

New Safety Action Items:

Resolve the request by the Safety Professionals that the Safety Officer be appointed for one year rather than one month. No action.

Completed Safety Action Items:

None

Action Items:

T. Siggins/D. Engwall - Get the gun and line baked and get the Experiment running. We got beam on the first viewer at 4;45 P.M. on Friday, August 16. using a 5 mW HeNe laser attenuated by a 10-6. The plan is to get the drive laser system working next week.

G. Biallas - Make a new ceramic stack and make a new cathode support tube with a anti field emission coating. See last week's report weekly report by G. Biallas

R. Legg - Investigate an alternate scheme to use the Longitudinal apparatus to perform the high voltage portions of the Transverse experiment. B. Dillon Townes will put together a drawing of the proposed line , working from information from D. Kehne. D. Kehne will get the proposal done by Aug. 22. No progress on the drawing.

Determine the need for additional personnel required to match or beat the Schedule. Julian is providing more diagnostics people.

T. Siggins - Write the tricks of polishing learned at SLAC. No action.

G. Biallas - Finish the LCW System: Flow & Temp reading, Level indicators, Full qualification walk through needed. No action.

K. Jordan/S. Benson - Failure analysis for the 10 MeV beam handling. No action

M. Shinn - Put phase noise documentation on the web. Starting to get this resolved.

All - general cleanup after bake. Partially done.

R. Legg - Publish the straw man for the 10 MeV Experiment . Files need to be compatible with the Web.

G. Biallas - integrate the new experimental schedule developed by Bob Legg into the main schedule. At the 90% stage as published. B. Dillon Townes - Get the 10 MeV beam line signed off. The remaining third in signature this week.

D. Engwall & D. Kehne - Present the transverse simulation results at 250 kV and the longitudinal simulation results at 350 kV. D. Engwall has started the transverse runs.

D. Kehne - In the proposed, combined 350 kV proposal, utilize the a bakable solenoid from the University of Illinois for the solenoid in front of the Chopper rather than the built-in solenoid. D. Engwall to get the drawings. B. Dillen Townes to get the magnet.

G. Biallas - Resolve another way to install the Running Resistor. The proposed method is under consideration by D. Engwall.

T. Siggins - Do a walk through the gun and beam line and install shields on ceramics and strain relief on cables to prevent the line from being damaged. No action.

S. Benson - Get the simulation data from B. Yunn to find out if we need to have a shielded valve between the gun and light box and order the appropriate valve. Calculations indicate no effect. However, the calculations are suspect because they are only for relativistic beams. The shielded valve is a conservative choice.

New Action Items:

R. Legg - Decide if the gradient reducing spacer on the gun should be removed for the 350 kV run.

C. Hiller - Make new Chopper probes.

Completed Action Items:

K. Bohn - Produce the design for the multislit for 10 MeV. Theoretical work is on track and personnel are assigned. Complete.

K. Jordan - Get the bunch length measurement contract signed. In Procurement's hands. Complete.

C. Piller - Have both the chopper cavity and the buncher cavity plated or painted to withstand the 250 °C bake. We will paint the cavities. Complete.

K. Bohn/R. Legg - Resolve where the Quartercryomodule should be tested first, in the Cryomodule Test Cave, testing one cavity at a time for basically a window test or to go through the disruption now and test in the ITS Enclosure in the offset position, coincident with the Longitudinal experiment. We need the Quartercryomodule in the cave in the November time frame. The SRF folks can have it for their testing in the intervening time. Complete.

T. Siggins - Resolve a way to guarantee the gun or line don't get damaged while anyone works above them and enforce the protection requirement. A tarp will be installed and available for reconfiguration. Complete.

S. Benson - Find out the material Duke used to eliminate the corrosion effects of a bake on copper. Not usable on our gun. Complete.

L. Dillon-Townes/C. Sinclair/H. Liu - Do the simulations and Resolve if the solenoid before the cryomodule can have its ID made larger by 1 cm. Yes, virtually no effect. Since the Injector has used the steel shell from our solenoid, we will make a new shell with the new bore. Complete.

Individual Reports of 8/16/96:

G. Biallas:

WESGO reports that their delivery of the ceramic bodies has slipped to Sept. 20 from Sept. 3. D. Lloyd is working the problem.

The rotisserie to do the Ion implantation on the ceramics at LBL was drawn by W. Sachleben . L. Turlington will get it done.

Six coupons of ion implanted alumina from LBL were tested. All went to low resistance before reaching an acceptable gradient.

The new cathode support tube is being machined.

The electrodes to assess the usability of the anti field emission coating for the cathode support tube are being polished.

The new slug of material for the new Mid Voltage Ring is received.

R. Legg - The week's activities centered on commissioning the gun's 500 kV beamline with low-current beam. The gun was operated with a nominal beam current of 10 nA with a 5 mW HeNe drive laser, while keeping the photocathode at a standoff voltage of 250 kV. Quantum efficiency was difficult to measure because of an alignment problem with the HeNe, but worst case is 0.2% at 1 microamp per milliwatt. The transverse emittance of the beam was measured and compared to simulation. An estimate of the emittance is 0.5 mm-mrad. Pictures of the beam on the first two viewers can be found on the WWW at URL, www.jlab.org/~legg; they are the 1stview.jpg and 2ndview.jpg.

- Attempts to align and operate the Nd:YLF drive laser proceeded in parallel. Tests of the drive laser's performance using the CEBA rf control software and an external master oscillator showed the output power remains the same, or slightly improves. The phase noise (timing jitter) drops, from ~ 0.8 ps to ~ 0.6 ps, due to the better performance of the master oscillator. There was, however, a problem with unstable second-harmonic-generation output. The doubling crystal was inadvertently damaged by way of unanticipated rf software problems which caused a Q-switch. We are procuring two additional crystals. Procurement should proceed rapidly (one crystal arrived-Friday, 23 Aug) because the vendor has the crystals in stock. Lost time from this mishap is only one day. We also are developing a procedure to avoid the problem in future laser operations.

J. Fugitt:

M. Shinn:

R. Walker:

Enclosures:

ITS Schedule for 8/20/96