MEMORANDUM
To: Distribution
From: F. Dylla
Subject: Monthly Report IR Demo FEL Upgrade and Commissioning
Project, October 1997
Date: November 24, 1997
Management
October 1997 was the third month for the $3.7M IR Demo FEL Upgrade
and Commissioning project. Cost and schedule performance are described
in the accompanying "Performance Assessment" report
by Gordon Smith. Four cost accounts with appropriate task identification
and earned value for task completion were established for the
project. A summary of the technical progress of the four cost
accounts is given below.
CA 221: Scaleable Optical Cavity
R5 Activity
Discussions were held with NAWC personnel regarding optics requirements
and the resulting derived coating specifications for mirrors.
NAWC has agree to assist in the calculation of mirror reflectivities
in the R5 geometry at 1.6 microns using existing codes and assuming
hafnium oxide/silicon dioxide stacks. They will also look at possible
alternative materials. We also held a vendor visit to Alpine
Research Optics to discuss issues regarding fabrication of R5
mirrors. Preliminary discussions were held with our own designers
on establishing the R5 cavity within the physical constraints
established by the magnets and vacuum system as they now stand.
CA 321: Upgrade Cryomodule System
Four cavities were prepared, processed and tested for the upgrade
cryomodule system. Incremental improvements are being made to
cavity processing techniques as cavities for the upgrade cryomodule
are being tested. The process changes and resulting effects are
being documented. The cavity processing schedule allows time
for several cavity processing cycles before final selection for
cryomodule production.
A talk was presented by J. Mammosser and J. Preble on the Cryomodule
Production Process at a Virginia Beach meeting of the Society
for Engineering Management.
CA 421: Commissioning Preparations
Remaining activities in this account include: (1) the final
measurement in the arc dipole magnets; (2) the completion of
the delivery of the corrector magnet purchase and (3) receipt
of the final components and testing of the analog monitoring system.
CA 521: IR FEL Commissioning
After modifying the high-voltage transmission line for the gun
to improve its stand-off voltage and SF6 seal integrity, and then
successfully reinstalling it, we conditioned the gun to the required
voltage for first light. High-voltage conditioning proceeded
rapidly, as has been the case in past attempts. We then ran beam
at 350 kV from the gun through the buncher cavity to a viewer
assembly just upstream of the injector cryounit. The buncher
was operated at its nominal power loading of 2 kW. The drive
laser in its final configuration ran to the required level of
performance in these tests. We now await completion of SRF and
RF commissioning of the cryounit before continuing to move electron
beam down the injection line.
SRF commissioning of the injector cryounit began the last week
of October. The exit cavity was operated at gradients up to approximately
9.5 MV/m until waveguide-guard vacuum trips ensued. SRF commissioning
activities were halted and leak-testing began. On 30 Oct. 97,
leaks were found at the interface seal for the warm window. The
cryounit was then warmed up to allow removal of the warm-window
assemblies and installation of new seals. Cool-down was slated
for (and accomplished on) Tuesday, 4 Nov. 97.
FEL INSTALLATION
Installation highlights for October are:
The injection line from photocathode-gun assembly to injector
dump is now fully installed and ready for commissioning activities.
All components for the drive laser assembly and drive laser transport
have been completely installed, aligned and tested for operation.
Shielding for the injection-line dump was put in place.
The optical chicane vacuum chambers were replaced after they were
removed for a minor modification needed for fit-up of BPM assemblies.
Final assembly of the wiggler vacuum chamber within its supporting
frame was completed.
Considerable progress was made installing the transport lines
leading to the first-light and recirculation dumps. The dumps
themselves are installed.