FEL Commissioning Activities

This week was devoted to continued preparation for resumption of commissioning. Bake of the gun was completed. High-voltage processing to 420 kV was also completed, and we made a cathode today (Friday, 29 May 98). Plans are to turn on electron beam Monday morning, 1 Jun. 98, consistent with the schedule we had devised two weeks ago.

Considerable progress was made in writing procedures to support the Phase Space Setup Metaprocedure. In particular, another systematic procedure for setting up the RF gradients and phases in the cryounit was written. We now have three methods for cryounit setup, and after turn- on we are planning to implement all three in an effort to reconcile them and get them to agree. Other procedures drafted this week concern resteering after rephasing the cryounitcryomodule, and rematching to the wiggler and dump. We also updated the procedure for difference-orbit measurements, and we completed a set of numerical simulations to ascertain better the expected beam quality at the locations of key diagnostics.

Dr. Uwe Happek of the University of Georgia spent the early part of the week with us. He delivered the hardware for the interferometric bunch-length monitors and assisted with their fit- up. By the end of the week the two devices were installed and aligned.