MEMORANDUM
To: J. Albertine, D. Helms, W. Skinner
cc: Division (M7), FEL Coordination Group
From: F. Dylla
Subject: IRFEL Weekly Report, July 7 - 11, 1997
Date: July 11, 1997
Management
SURA received the June 9-10 MTAC meeting report from Adm. Baccioco.
The committee made recommendations to SURA and Jefferson Laboratory
for dealing with the current lack of Navy support for FY 98 funding
and optimizing the use of the soon to be released FY 97 funding.
The Navy High Energy Laser Program office, the DOE Site Office
and Jefferson Lab have agreed on the final contract version documents
for release of the $3.7M of FY 97 funding to support commissioning
preparations, commissioning and continuation of upgrade activities
through Sept. 30, 1998. The documents are currently in sign-off
in the Navy.
The first round of pre-proposals to be forwarded to DOE-BES for
initial use of the IR FEL were received this week for review.
By week's end, 8 pre-proposals were in hand out of 12 that are
known to be in preparation.
Highlights for the week on FEL construction activities include
cooldown of the cryogenic transfer lines, injector quarter cryomodule
in the FEL Building, the final cryounit for the linac cryomodule
was complete, and the injector drive laser was briefly operated
in the new clean room.
Injector drive laser
The laser was operated briefly and was found to not be misaligned
due to transport so we will now build up the rest of the injection
laser system around it. The chiller water and power to the laser
has been established. Some problems with water purity still remain
and are being resolved. The rest of the equipment from the ITS
Clean Room has been moved to the new clean room. Move complete.
Accelerator Systems
Regarding the beam-transport system:
Additional magnetic measurements of the first optical chicane
dipole continued. Adjustment of the field clamps allowed us to
achieve the required effective length at the centerline to within
the specified 0.01%. Determining that the effective length at
other positions on the horizontal plane to the one part in 10,000
level awaits completion of the modifications to the magnet measurement
apparatus. Meanwhile, Everson Electric glued mu metal to two
more DW cores and are going to start final magnet assembly on
those cores and continue further core gluing on Monday.
Anticipated receipt of the finish ground back legs and of the
water jet cut brass shims early next week will complete all cores
and parts for the reverse bends by Process Equipment Co. All
coils for these reverse bends have been shipped to Everson Electric
for assembly. Winding form mounting and preparation and application
of conductor insulation in anticipation of winding the 180 degree
coils is complete. Machining of the large pole tips is continuing
while a rush torch cut out of existing material, rapid rough machining
and a quick, small batch heat treatment is allowing Process Equipment
to recover from discovery that the original back legs were torch
cut well under specified size. Master Machine sent core and parts
sets for a DU and a DV to Everson Electric for assembly.
The modifications to the magnet measurement stand for measuring
uniformity within a dipole family remain in fabrication with completion
expected in one week. Realistic planning of the magnetic measurement
effort, now possible with knowledge of the probable receipt dates
for assembled dipoles, indicates that measurement of the 180 degree
dipoles will run several weeks beyond October 1. Getting started
on the design next week by working in parallel would forestall
this schedule overrun. M. Wiseman is working the issue.
The Panofsky trim quad contract was awarded to Magnet Enterprises
International. Twelve of the 48 sextupole coils were shipped.
Sextupole cores are somewhat delayed with completion now expected
next week. The three quads for the recirculation dump line are
on schedule at New England Technicoil.
In the corrector area, details of the core and coil drawings and
the assembly for the phasing dipoles were signed off. We assured
ourselves of minimal fringe field cross talk from the 180 degree
dipole field clamps by consulting with the field measurements
from the DW dipole at 42 MeV excitation. Details of the two,
8 inch mu metal correctors were in process. The design of the
constant perimeter, air core corrector horizontal coil started
in earnest. I am investigating inexpensive water jet cut keys
are being investigated to locate the coils with respect to themselves
such that the assigned conductor placement achieves the required
1% field accuracy.
Welding of the bodies for optical chicane chambers continued with
a projected completion date of July 18. Pump down of the 60 inch
test piece chamber indicated that contamination from the machining
oil that the X Chamber experienced is not significant. We will
complete the X and Y chambers as welders become available. The
reverse bend chambers were signed off. Procurement was split
into two parts-a quick contract with an incentive payment for
making the straight pieces. This will get us parts soon enough
to our supply of trained welders. A second procurement will
follow, with more competitive bidding, for the remainder of the
parts that will match the follow-on welder availability. Drawings
for the arc dipole stands and girders for the trim quads and sextupoles
are in back checking while drawings of the beam pipes and stands
for the dump lines are in signature.
LCW was turned on in the header in the enclosure and the volume
of water is in clean-up mode.
The remaining two probes to allow zeroing out the dipoles at the
switch points to the three dumps were ordered. Design of the
mounting bracketry will start next week.
Regarding cryomodule fabrication:
Cryounit
The final cryounit was completed and handed over for cryomodule
assembly this week. Post assembly review of special FEL components
and procedures is underway.
Cryomodule
The remaining two bridging beam pipes have been installed. This
required the venting of the third cavity pair due to a valve leak,
see last weeks report. This work was completed with no unexpected
actions. The supply side transition beam tube has been installed.
Helium circuit interconnecting pipe work is completed and requires
leak checking. Assembly and clean-up of helium circuits is on
schedule for a 4 August installation into the FEL building.
Regarding electron-beam instrumentation and controls (I&C):
The focus this week was reestablishing remote control of the drive
laser. This should be done by 7/15/97.
All three networks are operational; the CHL network for running
the cryogenic systems, the Controls LAN for operating the accelerator,
and the CEBAF LAN for connection to the main CEBAF computers and
printers. The racks and tables have the AC power connected in
the control room and most of the RF gallery. Reconnection of
the ITS server for drive laser operation is proceeding well, the
drive laser controls should be up by Tuesday of next week.
Design work is proceeding for the Analog Monitoring System (AMS),
this system and the video distribution system is based on a 16x16
200MHz cross point switch. The assembled printed circuit boards
are purchased from Analog Devices for $500 each. They are meant
to be a demonstration board but it is a perfect match for multiplexing
128 analog channels to 16 channels (and ultimately to 4 ch.) and
for mux'ing 64 video channels to 16 outputs.
The new servers for the FEL control system were installed in their
final location. The ITS server will run the drive laser controls
and be used for RF commisioning while the new server configuration
is tested. When the new servers are proven to be stable, the
controls for quarter cryomodule RF and driver laser will be moved.
FEL Systems
Wiggler
More optical equipment was moved to the laser clean room and the
laser was run successfully. The clean room is still awaiting
certification. The two new drive laser cans were ordered. The
light box was place in position and the gun was aligned. Both
were grouted. The bakeout cart was also moved to the FEL building.
WBS 9.4 IR Demo wiggler
The wiggler is now in the FEL facility. The wiggler vacuum chamber
support was assembled and fit up to the wiggler. A clearance
problem was found between the wiggler magbase bolts and the support
requiring about one man-day of machining to correct. This will
be fixed next week.
Optics
Optical transport stands in the accelerator enclosure have been
installed. Optical tables were modified and re-aligned to less
than 1 mm of perfect alignment. That meets spec. Design of mirror
cassettes have moved into detailing phase. The optical collimator
was recleaned and received. We are beginning to align it.
Commissioning/Operations
Analysis of the data collected during the last series of experiments with the photocathode gun is continuing. Regarding longitudinal properties of the 135 pC bunches, the data concerning energy spread versus longitudinal position, as well as the data concerning bunch length, agree remarkably well with code (PARMELA) predictions. However, several issues remain, most notably a disagreement regarding transverse beam size. Specifically, the transverse rms beam size at the gun's aperture appears to be much larger than predicted by PARMELA, and tails are seen to form at the edge of the bunch. Data reduction continues.
Successful tests of the multislit transverse-emittance monitor
during experiments with the photocathode gun had led us to consider
designing and mounting one of these devices at the gun's light
box as an aid in monitoring the gun's performance during commissioning
and operations. However, in view of cost and schedule, we are
putting this on hold until we can bring it through design, fabrication,
and installation without stalling higher-priority projects already
programmed. Nonetheless, we are also firming up the projected
cost and schedule for the additional instrument. It is not required
for commissioning but would be a nice augmentation of the baseline
diagnostic suite.
Facility
Work is winding down on the facility. This week there was more
work on punch lists. The HVAC balancing continued. The chilled
water system was inspected by the contractor and cleanup of the
water performed. Grading of the site continued in preparation
for asphalt in the parking areas and loading dock next Monday.
Concrete was poured for sidewalks around the window areas, near
the street, and on the upper level exit stairs. The berms were
leveled. Punch list work continued in the elevator. Rubber pads
were placed on the stairs and the stairwell painted. General
cleanup continues. Jefferson Lab work included a lot of electrical
hookup to racks. The LCW was turned on upstairs and mods were
completed downstairs to provide better access to the gun. Considerable
effort was devoted to getting RF online and during the week the
cryomodule low level controls were cycled on a portable computer
for the first time. The cryounit was filled with helium and is
ready to bring down to 2K. Klystrons were placed in the Zone
1 HPA. Communications networks were expanded around the building
and brought online. We now have communication to the server just
as was available in the ITS, all programs that were there are
now available for hardware checkout. There will be a switchover
to the final server configuration around August 1 as that new
server facility becomes fully operational. Phones are getting
installed in the building we have a number of analog phones now
available. The chiller was brought into operation for the drive
laser. The mounts for the optical transport lines for the FEL
output were mounted on the ceiling. Installation of the cans
should begin next week. The gun was surveyed into position then
grouted down. The 10 MeV dump, light box, gun controls, etc.,
etc. got delivered from the ITS into the building. The wiggler
with its table and quadrupoles was delivered to the building but
awaits alignment before it will go to its final position. Both
optical tables were re-positioned and surveyed in. We have now
locked that down and can begin installing hardware on them. The
remaining back leg quad girders were installed. Survey performed
a check of the building matrix and discovered a 1mm expansion
in length since February. Whether this is seasonally related
or part of the building settling remains to be determined. We
intend to monitor this on a quarterly basis until the question
is resolved. Progress continued on the gun high voltage power
supply installation. The control room is getting set up with
the communication cables to the tables, phones, a printer on the
net, a scanner, and rack hookup continuing. We continue to work
with the vendor in getting the clean room air controls to meet
our needs as regards humidity and temperature.