FEL Weekly Upgrade Report
June 12-16, 2000


The FEL Upgrade Kick-off meeting was held this week on June 12-13. Next week we will host our biannual Laser Processing Consortium/FEL Users Workshop on June 19-20.


The FEL Team hosted a project kick-off meeting for the 10 kW IR FEL Upgrade project this week on June 12-13. John Albertine chaired the review committee that included C. Brau (Vanderbilt), M. Gouge (ORNL), H. Freund (SAIC), and R. Wenzel (NRL). The team successfully defended the design and planning for the project. The committee made constructive
suggestions for improving the execution of the project, which were summarized in a committee report which was distributed today. The primary concerns are the tight budget and schedule constraints and a request for a back-up optical cavity option to lower the risk of any potential problems with the new R5 cavity design. The project team thanks the committee for their attentiveness at the review and the expeditious delivery of their report.

Design/Construction Activities

WBS 4 (Injector)

We had discussions this week with the Chief Engineer from Glassman concerning our plans to drive our present gun HV power supply to 10 mA. We may have to add an additional voltage multiplier stack and make the HV tank longer depending on the outcome of these design discussions.  Plans are in place for the ion implantation of the second ceramic stack
assembly for the gun later this month at LBNL. This technique was successfully used in our present gun to prevent arcing damage on the ceramics.

WBS 6 (RF)

We updated the interlock requirements for the new RF system. CPI, the vendor which won the high power klystron procurement, has requested the design review for the 100 kW klystron be held 29 August rather than 2 August. We agreed, if they would commit by 7 August to the power supply specifications to drive the klystron.

WBS 10 (Wiggler)

A 3D layout drawing for the wiggler assembly was completed and shown at the kick-off meeting. The detailing on this drawing is almost complete.

WBS 11 (Optics)

Activity was accomplished in WBS 11.5 (diagnostics). We ordered a pyroelectric array for continuous monitoring of the FEL wavelength, which also can be used to automatically lock the wavelength (and thus the e-beam energy) to a given value. We added FEL diagnostics to the end-of-line dump region and tested a technique for optimizing the extinction ratio of the drive laser pulses. It seems to work fairly well, so we will move toward a simpler implementation of the technique.

Operations/Commissioning Activities

In preparation for the summer user run which is scheduled for June 6-August 4, the FEL will begin hot checkout tests on Monday which will continue all week. Today a new chamber for detecting the sub picosecond x-rays that are produced in the IR FEL by Thomson scattering was installed in the machine and vacuum qualified for use in the upcoming user run.