# MEMORANDUM 

**To:** Distribution

**From:** F. Dylla

**Subject:** FEL Upgrade Project Weekly Brief -- November 17-21, 2003

**Date:** November 21, 2003

**Highlights:**

Over the last week we made substantial progress in re-establishing
lasing in the FEL. Early in the week rf windows were replaced in 6 of 8
cavities in cryomodule 2 and the module cooled back down to 2K.  We then
turned the beam on and threaded beam through the linac and new arc
magnet.   By the end of the week we were fine tuning the beam focus to
permit CW operation with beam all the way to the dump.  We intend to
operate over the weekend to establish CW lasing and then lase.  We also
intend to run over the Thanksgiving weekend in order to recover some of
the time lost because of Hurricane Isabel. The new 180 bend arc magnet
(GY) is working fine.

**Commissioning:**

See Highlights.

**Management:**

The DOE Jefferson Lab Site Office received the full funding last night
from ONR yesterday for our first phase of FY04 FEL Upgrade activities.
This means that a total of \$4M of FY04 ONR funds has been transferred
to cover completion of commissioning, subsequent performance testing,
and the design and procurement of the one micron wiggler, optical
transport system to the user lab floor, and final sextupole/octupole
magnets for the accelerator driver.  We thank the ONR Program Office and
the DOE Site Office for their efforts to get these essential funds
released.\
\
A semiannual report summarizing the progress on the UV FEL upgrade over
the period\
April 1, 2003 through September 30, 2003 was completed and sent to our
UV FEL program manager, John Eric, at AFRL.  Briefing material was
prepared for next week\'s visit on Nov. 25th by John Eric to review both
the last six months of progress and the planned FY04 activities on the
UV FEL upgrade.\
\
Project monthly reports for October 2003 for the JTO funded projects and
the US Army funded THz project were prepared and sent to the respective
program offices.\
\
A detailed FEL operational schedule for the FEL was prepared and posted
for the next 2 months.\
In addition, a preliminary FEL operations schedule is being prepared for
the remainder of FY04 for integration with the CEBAF operational and
maintenance period schedule.

**WBS 4 (Injector):**

On Wednesday of this week the photocathode gun delivered 350 kV, 30 pC
pulse beam for FEL operations for the first time after the recovery from
hurricane Isabel. On Thursday we performed a cathode re-cesiation to
bring the QE from 0.5% to 5%. It takes only about 15 min to re-cesiate a
cathode, and about 1 hour after that to qualify its performance at 350
kV before the photocathode is ready to deliver beam again.

> ![](media/image1.png){width="3.1868055555555554in"
> height="4.009027777777778in"}

We also took more data on the field emission test stand with the coated
SS electrode. We are cleaning support mounts to install a 9-micron
surface finish SS tube with a welded flange into the W&M's Plasma Source
Ion-Implant chamber, in preparation for a thick coating implant test.

**WBS 5 (SRF):**

[FEL03:]{.underline}

The space frame is now installed on the third FEL cryomodule. This is
the last major component before insertion of the string into the vacuum
vessel, however a number of operations remain before that can happen.
Next up, the thermal shield has to be hung and aligned inside the space
frame, then the cold mass support is transferred from the assembly
tooling to the space frame and finally the whole assembly is surveyed
and aligned. The crew is working hard to try to meet the Christmas
delivery.

![](media/image2.jpeg){width="4.194444444444445in"
height="3.1381944444444443in"}

**WBS 6 (RF):**

The cryomodule warm windows for cavities 3 - 8 of zone 2 were replaced
with poly material from ceramic last weekend. The cryomodule was cooled
back down to 4°K then to 2°K this week. It was then powered with RF and
successfully tested. All except 1 cavity achieved their

DRVH values within a few hours of operation. The final cavity was within
5% of its DRVH value. CWWT faults are no longer a problem.

All RF systems are operational.

**WBS 8 (Instrumentation):**

We are pleased to resume the task of providing support of FEL beam
operations. This week's activities include resolving minor configuration
issues with the AMS due the down-time activities as well as
troubleshooting the \'spare\' ADC inputs being used by the calorimeter.\
   

The UDP error messages received by the framegrabber from the IOC have
been solved. The framegrabber no longer times out or aborts do to a
heavy load of channel access. With fast efficient use of the network\'s
bandwidth, the framegrabber now runs smoothly and will not tie up
resources. Extensive testing of the center-of-mass calculations proved
that the algorithm determined the proper values only a portion of the
time. The algorithm has since been reviewed and the problem has been
found. This routine is now in the process of being reworked to simplify
the amount of decisions it is making about the image.\
   

Installation of power, controls, air and alignment of the Calorimeter
were completed.  The two PCB boards for the Calorimeter chassis have
been assembled and tested.  The chassis was bench tested and installed.
There are plans to begin experiments this Sunday. Al Grippo is currently
working on the EPICS screen for the read backs of the system.\
   

Two fail-safe interlock boxes have been designed for the OC insertable
diagnostics dump and the OC insertable diagnostics mirror.  The
interlock boxes prevent both solenoids from being inserted at the same
time by taking read backs from both the In and Out limit of the opposing
solenoid, thus preventing damage to the system. The beam viewer cross
test assembly was resurrected in order to complete final alignment of
silicon viewer chimney stacks.\
   

Work continues on the Video/AMS upgrade. EES has partially populated the
32 channel video distribution amplifier boards (F0269). Their work will
continue early next week as we receive the balance of the parts needed
for the board. In parallel, the video output distribution chassis is
being fabricated in Lab 5. This is the chassis that the inline amplifier
boards will be used in.\
   

The configuration control database has been updated to include the work
break-down structure (WBS) interface for system owners. This will allow
for electronic folders containing system specific documentation to be
readily accessible online. It is planned that the upgraded documentation
system will be made available for group use in the next 2 weeks.\
   

A spare Charge/Dump Current Monitor Buffer Driver Box has been built and
tested in the control room. It will need calibration if it is installed
in the vault. Drawings for the BLM Card, the Video VDA card and the MGC
Magnet control card have been signed.

 

**WBS 9 (Beam Transport):**

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

• The newly installed 180 degree dipole in the first arc performed as
expected when bringing up the machine this past week. The path length
adjustment (GG Coils built into the GYs) only had to be invoked to less
than ten percent of their capability, meaning that the combination of
measurement and alignment of all the magnets in the arcs approaches the
model very well.

***Sextupole (SF)***

• We are continuing the revamping of the SF drawing set. Layout of the
revised cooling scheme is complete and many drawings have had a first
pass revision. We are now in final detail, call out and materials block
checking.

***Octupole (OT)***

• New England Technicoil is painting the two cores and will ship next
week.

**WBS 11 (Optics):**

This week we reopened the vacuum valve that connects the outcoupler
optical assembly to the beamline (and our diagnostics).  Initial results
show a slight decrease in angular jitter and a slight shift in resonance
frequency.  We took advantage of the recesiation of the photogun to
confirm that the insertable, water-cooled mirror that will route high
average power beam into a commercial beam dump is well-aligned to the
viewport.   We also realigned the optical diagnostics that will be used
to check the laser performance.  The new outcoupler mirror holder was
nickel-plated, and is ready to have the new outcoupler, which should
arrive from the vendor early next week, after the vendor completes
inspection and laser calorimetry.  The refigured and recoated HR mirror
was received today and will undergo QA later today.  With help from I&C
as well as EES staff, we had the high quality RF cable that feeds the
sync signal to the ultrafast laser in the vault reterminated, and we got
the synch signal circuit (conditioned photodiode output generated from
the \"waste\" IR light from the drive laser) working. 

 

The drive laser ran well for operations, but as the e-beam is the
ultimate test of extinction ratio, we learned that we didn\'t gain as
much in throughput as first believed.  We took some time during the
recesiation to do some alignment; some more work remains.

**Terahertz Project:**

The preliminary drawings of M1, M2, M3 and M4 and their respective
holders were completed.  The ellipsoid definitions were refined to
higher accuracy consistent with specifications required for the diamond
turning machines.  Note that further refinement of the mirror sizes and
figures will take place next week when the full propagating electric
field is calculated using the Synchrotron Radiation Workshop code in
Saclay, France in collaboration with Oleg Chubar and Paul Dumas.  Work
started on documentation for the pre-construction design review, which
is expected to take place in mid-December.

**FEL Technology Transfer Activities:**

A Joint Ownership Agreement (JOA) has been negotiated between four
organizations involved in carbon nanotube production at the FEL:
Jefferson Lab, College of William and Mary, NASA, and Penn State
University. Ownership of the Intellectual Property is based on
contribution to the invention from each organization and researchers.
The JOA acknowledges that massive quantities of carbon nanotubes can
only be produced at the Jefferson Lab FEL. The JOA also describes
marketing strategy, licensing procedures, and royalty streams. (All we
need now is beam!)

Jefferson Lab continues to work with the Hampton Roads Research
Partnership to facilitate multi-disciplinary collaborative research
efforts between the centers of excellence in the region. A business plan
for the establishment of a Hampton Roads Research Institute has been
presented to the Virginia legislative staff for inclusion in next
year\'s state budget.