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, L. Dillon-Townes, D. Engwall, J. Fugitt, K. Jordan, D. Kehne, G. Krafft, R. Legg, W. Merz, C. Piller, C. Sinclair, R. Walker, M. Wiseman

General Announcements:

None

Decisions/Comments:

All regular installation will stop when the cathode is changed next week.

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.

New Safety Action Items:

R. Legg - Notify RCG of the new running conditions in order to reestablish radiation controls on the Mezzanine if necessary.

Completed Safety Action Items:

None

Action Items:

T. Siggins/D. Engwall - Get the gun and line baked and get the Experiment running. See last week's report weekly report by R. Legg.

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. Scheme is feasible with a new solenoid and some modification to adapt to the probes on the chopper. This issue will be closed out at a meeting this week.

Determine the need for additional personnel required to match or beat the Schedule. A Post Doc is on order. R. Legg is requesting a mechanical tech position from C. Rode. R. Walker reports that the Electrical documentation is falling behind.

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. Plant is investigating the gunk in their system. No answer as of yet. They would like to schedule a shut down to coincide with the gun RF and the buncher being down . This is going to fall during the CEBA Shut down when no personnel will be available. G. Biallas is working the problem.

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

M. Shinn - Put phase noise documentation on the web. No report.

All - general cleanup after bake. Partially done. Need the vacuum cleaner to be washed down and the filters changed.

G. Biallas - integrate the new experimental schedule developed by Bob Legg into the main schedule. At the 90% stage as published. No progress. \

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.

R. Legg - Resolve the effect of an unshielded valve at the Light Box and the chopper cavity both contributing to beam blow up when installing the Longitudinal/Transverse combined experiment. Contact J. Bisognano for intuitive feel.

G. Biallas - Investigate the report of an additional safety inspection coming.

All Personnel - Check your apparatus for sensitivity to LCW Pressure spikes

Completed Action Items:

R. Legg - Publish the straw man for the 10 MeV Experiment. Complete.

B. Dillon Townes - Get the 10 MeV beam line signed off. Complete.

Individual Reports of 8/30/96:

G. Biallas:

The drawings for the rotisserie to do the ion implantation on the ceramics at LBL were signed and L. Turlington is getting local manufacturers to make them.

The first coupons of ion implanted alumina were tested. They were generally two orders of magnitude too resistive. Some breakdown style effects at voltage lower gradient than required were seen on all samples tested at 3/4 inch length. This effect is believed to be an artifact of the test because samples tested at 1/4 length withstood gradients 20% higher than necessary. The results indicate the ion implantation method may be the method of choice for establishing a voltage gradient on the ceramics.

New ion implantation coupons were being prepared at LBL with higher implantation doses and double 45 degree impingement to mimic the ultimate implantation method.

The electrodes to assess the usability of the anti field emission coating were polished and cleaned to be ready for insertion in the test apparatus at William & Mary this weekend.

The new slug of fine-grained material for the new Mid Voltage Ring was delivered to the shop for machining.

The new cathode support tube was completed in the shop and is ready to polish.

J. Fugitt:

The high gradient buncher waveguide installation is complete, and buncher is connected in the test cave ready to do power tests next week.

The buncher was connected to the temperature control skid and the temperature stabilized at 120°F. The loaded "Q" looks very good at about 10,000.

The specification for the 8 klystron power supply has been reviewed, and with a little cleanup, will be ready to go out next week.

R. Legg

Commissioning of the 500 kV beam line for the Injector Test Stand continued. Using beam extracted from the GaAs photocathode with a HeNe drive laser, the transverse emittance measurement system was tested and the design dispersion for the magnetic spectrometer was verified. Switching to the doubled Nd:YLF (green) drive laser, the system successfully delivered a 22 micro amp beam to the beam dump with the drive laser operated at a total power of 5 mW at a 75MHz repetition rate. With the drive laser power increased to 0.65 watts, a 1 mA average current beam was delivered to the dump. The peak charge per bunch was in the range of 25 pC. With this successful test of all the beamline components and instrumentation, the gun assembly will be taken off line next week to change out the GaAs cathode. The present cathode has a crack and is misaligned but we were able to work around these problems by manipulation of the drive laser alignment.

M. Shinn:

Re-established SHG (green) output from the drive laser.

Re established (with D. Engwall and B. Legg) SHG output on the photocathode.

Delivered stable output to the photocathode in order for low (mA) and higher (1 mA) currents to be extracted.

Met with several (K. Jordan and R. Walker) members of the rf interlock team to review progress towards our short-term goals.

R. Walker:

New drive probes for the Chopper cavity are being designed by C. Piller. It will be several weeks before they will be ready for testing.

The fiber optic cables for the Arc Detectors on the 50 KW system have been installed for the klystrons output windows and the circulators.

Discussions was held again this week on the RF system software for the IR FEL. A list of parameters was given to the software group.

The Buncher cavity has been installed in the test cave, but its water skid has not. The controller needs further checkout.

The finished Arc Detector units will be assembled, tested, and installed within 2 weeks.

Klystrons operating at 8 KW have now been operating for 1.5 weeks. There have been numerous unexplained crowbar trips.

Preliminary RF software is running for the Drive Laser, Chopper, and Buncher. A hardware bug is preventing the checkout of the code for the Quarter units.

Enclosures:

ITS Schedule for 9/3/96