MEMORANDUM

To: J. Albertine, D. Helms, W. Skinner

cc: Division (M7), FEL Coordination Group

From: F. Dylla

Subject: IR FEL Weekly Report: July 15-19, 1996

Date: July 19, 1996

Management

The June monthly report for the project was prepared and sent to the DOE Site Office and Navy High Energy Office. The report included a revised Cost Book and Earned Value tracking charts for the Navy funded efforts.

The FEL program was reviewed this week as a component of the SURA-DOE Annual Review of Science and Technology at Jefferson Lab. Outside reviewers who were asked to pay particular attention to the scientific and technical merits of the FEL program and its impact and benefits to the Laboratory's other programs included: Dr. Robert Siemann from SLAC, Dr. Arthur Bienenstock, Director of the Stanford Synchrotron Light Source, and Dr. Tim Antaya, Technical Design Chief for the Accelerator and Magnet Systems for B&W, Inc. The FEL program received an "outstanding" performance grade from the committee. The committee's written report will be forwarded when received.

FEL Accelerator Systems

A consultant on high voltage ceramics from Northrop Grumman delivered his report that will assist our formulation of a plan for rectifying the leaky ceramics in the high-voltage stack of the ITS photocathode gun. Several options were identified that can be incorporated into a follow-on stack. Plans are to operate the gun at 250 kV to generate high-current beam and correlate measurements of beam properties with simulations, and then replace the existing stack with a new one in the November time frame. The gun is presently undergoing a second bake due to a leaky valve that required replacement.

Drafted an updated schedule for development of the photocathode gun and began to assimilate it into the existing overall IRFEL schedule. Part of the process involves identifying options for accelerating various aspects of the gun development given the recent setbacks in its schedule.

Established the vacuum specifications for the beamline of the IRFEL. This involved assuring that ion trapping would not significantly degrade the electron-beam quality. Although refined calculations of ion trapping are forthcoming, initial calculations establish with confidence the viability of the vacuum specifications that had initially been projected.

Established that use of available, and therefore relatively low-cost, 4-channel beam-position monitors is consistent with requirements for machine protection. Worst-case vacuum-chamber burn-through calculations in the event of an errant electron beam indicated the burn-through time scale is sufficiently longer than the time required for effective operation of the 4-channel BPMs.

Operations/FEL Optical Systems

Operations

Plans for the Commissioning Workshop next week (July 24-25) are complete. A preliminary package outling the issues and a strawman approach to the problem was released on July 18.

Optics

Work concentrated on setting up an interferomter for measurement of mirror distortions under heat loading. The system is precise to better then 1/2 a HeNe fringe but absolute calibrations and tests are still in process. Many engineering design drawings are in preparation for the optical cavity. The design schedule seems to be holding for a hardware review in September.

Wiggler

There has been no local action on the wiggler the past week. Plans are in place for a magnetics review on July 29.

Facilities

Construction efforts have centered on excavation of the west end of the facility which is now at correct grade with foundation forms in place. Initial concrete pour of foundation is scheduled July 29. There was a monthly review with the contractor this week. Mid Eastern provided a detailed schedule which will meet all major milestones. The contractor was awarded a safety bonus for having no citable incidents during June. The construction is on track to one week ahead at the present time. CEBA has been briefly tripped off on several occasions by vibration generated by bulldozing. We are attempting to identify those specific activities which are the most problem so interference can be minimized.