**MEMORANDUM**

**To:** Distribution

**From:** F. Dylla

**Subject:** FEL Upgrade Project Weekly Brief -- March 24-28, 2003

**Date:** March 28, 2003

**Highlights:**

Three of the four second arc vacuum chambers were set in the magnets
with the fourth scheduled for early next week.

A test of 800 MeV energy recovery is proceeding well on the CEBAF
accelerator. This test is complimentary to the high current energy
recovery demonstration on the FEL and will establish a strong case for
ERLs.

First light diagnostics installation punch list was completed with the
installation of viewers in both the optical chicane and the first pi
bend.

**Special Meeting Notices:**

[FEL IR/UV Upgrade Semiannual Review: April 9-10, 2003]{.underline}

At Jefferson Lab (ONR/AFRL/DOE invitees only)

**Management:**

We held a teleconference with ONR to review technical progress and
financial status and resolve any issues which might be holding up
signature of our MOU and release of remaining FY03 funds. Commissioning
is meeting the schedule presented at the last review with the exception
of a 2 week delay in the installation of the final arc magnet and the
delay in gun startup which is now expected around April 15. The budget
is exactly on track with our projections.

Adm. Cohen presented the ONR FY04 plan to the House Armed Services
Committee. Our JLab poster was one of three displayed for the committee.
In attendance were technical heads of all the branch services.

A Statement of Work, cost, and schedule were prepared for ONR/Dahlgren
for a follow-on effort for the laser materials damage tests by
establishing an effects lab with a wind tunnel.

An agenda for our Semiannual Review on April 9-10 was prepared and
circulated to the speakers and program office. We began reviewing the
team\'s presentations for that review.

**WBS 4 (Injector):**

The ceramic stack was run up to 400 kV with the running resistor
completing the check out of the dual resistor transmission line. The
ball cathode and support tube have been repolished to 1um and are being
cleaned. A preassembly bake of gun subassembly parts is being done after
solvent cleaning.

Gun HVPS - Operated the Gun\'s HVPS to 572 kV. The Conditioning Resistor
was operated to 450 kV. Its resistance has dropped to 144 M Ohms. The
Running Resistor was operated to 400 kV. These parameters are sufficient
for first light operations. Noise was also noted on the current measure
and voltage ripple monitor ports. The current noise was about 300 uamps
for 2 stack operation. Two stacks are required for operations above 5 ma
of e-beam current. Discussions are ongoing with the vendor concerning
this noise.

**WBS 6 (RF):**

Zone 1 - Completed the tuning and started the re-checkout of the
Quarter.

**WBS 8 (Instrumentation):**

A pair each of the demo DU magnets have been placed at the Injection,
Extraction and temporary dump magnet strings to increase the load on the
5kW power supplies. Water, power and thermal interlock installation has
been completed. The 8 floating trim power supplies are being built up.
They will initially run with a 12 bit, MVME 628 DAC, when the new
\"Analog Block\" is complete they will be reworked and achieve higher
accuracy. The high voltage power supply was characterized for current
vs. voltage for operation with a single stack and with both HV stacks
connected. The new analog control card was also installed and
calibrated.

Final checkout of the vacuum system is being done. This includes
operating the valves both locally and through EPICS. The NEGs on the
differential pumping station downstream from the cryomodule is being
reactivated (region recirc dump).

Video Selection System - Documentation of the current system
configuration and the plans to upgrade the system with the vault patch
panels has been updated. The vault patch panels are essentially copies
of the patching system we currently use in each user lab except that
they have three video monitoring points. There are currently four of
these I & C stations with video patch panels being implemented. One in
the Injector area and three for the optical transport regions, namely
the high reflector mirror assembly, the output coupler assembly and the
wiggler region. These control stations are essential for the routine
diagnostics of the machine. Upstairs, all the new video cables currently
installed are terminated and are being dressed in to the main video
system (FL02B09). The I & C stations will also hold the Radiation Rapid
Access Control hardware and an assortment of analog I/O for general
purpose use.

MPS/DLPC Integration - The digital integrator module for upgrading the
drive laser\'s duty factor interlock is running in the test crate
(IOCFELT2) in Lab 5. It is communicating properly with the IOC and the
duty factor permit function is being checked-out.

Additional beamviewer cameras have been built to support installation of
the paddle viewers in the arc. Lab stock is being sorted and organized
so we are ready for maintenance when the time comes.

The following drawings were completed this week: F0117 VME Interface
Board, F0119 8 Channel Digital Interface Module, F0190 HV Interlock
Analog I/O, F0191 MPS Comparator Module, F0193 (RevA) User Lab Patch
Panel, F0182 (RevA) HV Interlock Chassis Rear Panel Fabrication. Again,
thanks to EECAD for their support in getting these drawings done and to
Document Control.

**WBS 9 (Transport):**

***Work Arounds***

Substitution of IR Demo 180° Bend (DY) for the Upgrade 180° Bend (GY) in
the First Arc and installation of a GW beyond the Optical Klystron as a
diverter-to-the-dump magnet

• We added more resistance to the circuit, of the temporary diversion
dipole at the end of the optical cavity. We tested the power supply and
it is qualified for full current.

***Dipoles***

[Optical Chicane Dipoles (GW)]{.underline}

• No progress.

[Injector Dipoles (DU/DV)]{.underline}

• We added resistance (using two IR Demo DU magnets) to this circuit.
The injection circuit qualified for full current.

[Arc 180 Degree Dipoles (GY)]{.underline}

• The machinists of the JLab Shop finished commissioning the measurement
apparatus for the GY dipole and did some of the measurement at the 145
MeV/c level.

• Preliminary data indicates field uniformity at 145 MeV/c of ± 2 parts
in 10,000 and a core field that needs only 0.5% shunting to match the
GQ/GX family. Core field at 80 MeV/c needs about 1.6 % shunting to
match. All these values better than or adequately close to
specification. 80 MeV/c measurements are being taken as this is written.

• Wang NMR is having difficulty potting the first coil of the second
dipole. The mold was not vacuum tight and had to be disassembled and
resealed. They plan to pot as this is being written.

[Arc Bend & Reverse Bend Dipoles (GQ, GX)]{.underline}

• The last GX magnet passed preliminary qualification measurements at
145 and 80 MeV/c in the IR configuration. Specification is 10 parts in
10,000. Readings are being taken of the UV configuration as I write.

• Late last Friday, the preliminary data showing core field 0.75 % low
led us to take resistance readings that discovered the new, lower coil
indicates one shorted turn. We replaced the coil with the original coil
after testing for and finding no leaks, even at 500 psi. We are puzzled
by the finding but decided to use the coil anyhow. This enabled the
reading above.

• A 1.5 day delay in testing the last GX was caused by the same phase
mismatch trips we have had in the power supply throughout the testing
period. Fortunately, these trips were not intermittent as they had been
in the past and the power supply group had diagnostics in place. They
appear to have finally fixed the problem.

• We installed the two GQ dipoles and one GX with two of the vacuum
chambers.

***Quadrupoles***

[Trim Quad (QT)]{.underline}

• The QTs were hooked to their power supplies.

***Sextupole (SF)***

• No news.

***Octupole (OT)***

• The order is ready to be placed anticipating the next batch of
commissioning money.

***Correctors***

• Hiroyuki Toyokawa is still working on the connection of the series of
parallel wires into form the coils of the GZ horizontal corrector within
the third GW dipole of the Optical Chicane.

• Jeff Dail of the JLab Shop started winding the coils of the GA
vertical corrector of the Optical Chicane.

**WBS 11 (Optics):**

We found the problem with the OC leadscrew (a loose fastener had caused
binding in the leadscrew) and fixed it. We pulled a vacuum on the OC
vacuum vessel and verified that a) it as running correctly in both
directions and b) that the Vespel nut was lubricating, and thus reducing
the drag torque. We received new mirror retaining clips for the thicker
ultraviewer mirrors we\'re using, and verified they can be installed in
such a way as to not affect mirror figure. We quickly changed out the
ultraviewer mirror and clips, however we still have some problems to
resolve. Nevertheless, it is improved, allowing us to begin optical
cavity alignment in earnest; first aligning an external HeNe through the
outcoupler and the center wiggler viewer. Using that, we roughly (to a
few 100 urad) aligned the 3\" and 2\" OC mirrors. We then used the
ultraviewer next to the HR assembly to align the 2\" OC mirror. By early
pm Friday, we were working on aligning the 3\" OC mirror, and will then
align the OC OCMMS optics. We\'ve also been running repeatability tests
and LVDT calibrations when the vault is locked up, or at night, so
we\'ve made a lot of progress this week. All this work on the OC
assembly required the help of the staff member working on the HR OCMMS
optical assembly, so it\'s progress had to be slowed. We anticipate
installing it in the vault next week.

***Other activities:***

We began preparing presentations for the Navy semi-annual review.