MEMORANDUM

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

cc: Division (M7), FEL Coordination Group

From: F. Dylla

Subject: IR FEL Weekly Report: August 12-16, 1996

Date: August 16, 1996

Management

Financial reports were issued and reviewed for the project expenditures during the month of July.

With the startup of operations of the injector test stand, physics and engineering support coordinators were appointed to orchestrate daily operations of the ITS.

Planning continued for the September LPC Workshop on Sept. 9-10.

Injector Test Stand

The ITS is a center of vigorous, well organized activity. A photocathode was fabricated and cesiated, and 3 microamps was extracted from it with white light. It was then processed to 300 keV and is now "routinely" subjected to 250 keV. The gate valve was opened to the beamline leading from the gun, and stable, compatible vacuum was established. The beamline instrumentation and magnetics are undergoing checkout. On Friday afternoon (16 August) at 4:40 p.m., we generated a 250 keV beam brightly visible on the first beam line viewscreen using only a nanowatt of HeNe incident laser power.

Completion of fabrication of the cryounit is now slated for mid-September. Because the cryounit is not on the critical path, some time is being devoted to taking extra care in its assembly.

Accelerator Systems

Theoretical modeling of the multislit apparatus for transverse-emittance measurements of the "10 MeV" space-charge-dominated beam are nearing completion. This activity will result in a data-reduction algorithm.

Calculation of impedances of FEL beamline components is a continually ongoing activity. For example, one product this week was an impedance analysis of shielded vs. unshielded valves for use in the beamline leading out of the photocathode gun.

About 70% of the design of the cryomodule is complete and several of the related procurements are started. For example, the bridging cylinders that link the component cryounits are in procurement.

FEL Systems

Wiggler

Initial discussions were held with the engineer in charge of design/fabrication of the wiggler support/girder. The design goals were covered and the specifications were discussed. We received magnet modeling software from SIM Limited and started to benchmark it.

Optics

The Pyrocam for beam quality measurements was ordered. Thermal modeling of mirror distortion due to coating absorption is continuing after problems with the computer at LBL were fixed.

Operations/Commissioning

The weekly FEL commissioning activities are currently focused on devising commissioning plans for sections of the machine. To do so also provides another check of the completeness of the beamline components that are planned for the machine. This week, a draft commissioning procedure for the first recirculation arc was developed.

Facility

The second third of the floor slab, including the UVFEL wiggler pit, has been poured and the forms for the exit stairway are almost complete. Much progress has been made on the wall forms at the west end of the building.