Highlights:
We began the process of recertifying the Laser Safety System (LSS)
for the start-up of the summer operations
period.
Management:
The project monthly report for April was distributed to the ONR and
DOE program offices this week.
We made final preparations for our participation in next week’s (June
5-6) JTO-sponsored workshop on
“Free-Electron Lasers for Naval Applications” which is being
held at the Ramada Hotel in Newport News.
Over 120 participants are expected from the Navy, industry and the
government labs.
On Thursday May 31, three visitors from DARPA (Tim Grayson, Gail Heim
and Sheldon Meth)
visited Jefferson Lab for a tour and briefing on the FEL program.
WBS 3 (Beam Physics):
A review of the QX quadrupole systematic multipole specification was
conducted. As the bore is larger than that
in the Demo, the specification can be relaxed from 1 ppt to 3 ppt without
untoward performance effects. The
prototype magnet meets the revised specification. The review is documentented
in JLAB-TN-01-027, available
on line at http://www.jlab.org/~douglas/FELupgrade/technote/JLABTN01027.pdf
WBS 4 (Injector):
Received the 6" RF shielded gate valve from VAT. Submitted the 10 to
6 MV/m spacer to the shop for
fabrication. Signed off the remaining shield door test drawings.
Reviewing the stalk drawings for sign off.
WBS 5 (SRF):
The weld development for the HOM couplers are complete with the first
two prototypes completed.
Cavity tests have shown a sloping Qo value on cavity JL005 with full
chemistry. This problem has lead to several
tests to determine the cause of the slope. So far tests have
indicated that the problem is not the indium seal and
the next test is to heat-treat cavity JL005 to 800C for 6 hours to
determine if niobium hydride precipitation (Qo
disease)is the problem.
Flange leaks have developed on the FPC flange and testing to resolve the issue has started.
WBS 8 (Instrumentation):
Getting ready for the user run has been a priority this week.
All of the LSS Lab Interface Box power supplies
were upgraded to handle increased current caused by more equipment
in the labs. The low level certifications
went well, there was only one minor hitch with the series/parallel
hutch bypass contacts on the optical transport
switchyard.
OBPM Picomotor controller chassis in system check-out and diagnostic
software made. Many of the zero &
tracking functions of the OBPM system have been tested using the drive
laser. We still only have 2 of the
Molectron sensors in house; the remaining prototype boards are complete
with the exception of those sensors
which are due in next week.
Requests for bids on assembly of the new Ion Pump Power Supplies went
out late last week. One bid has been
received so far.
The new silicon viewers have been tested with beam and work very well,
a decision whether to attenuate the
signal will be made Friday.
Work continues on the user power supplies and the web site upgrade.
Drawings were completed this week for the Front PCB in the Ion Pump
Power Supply chassis; the schematic of
the PCB in the Beamviewer Solenoid Control Box; and the Front Panel
Fabrication of the VME Timing Circuit.
Drawings in EECAD: IPPS Main Board Schematic; MPS System Drawing;
Analog Differential Driver Board
Schematic; Pyro-Electric OBPM Buffer/Amplifier; Picomotor Relay Chassis
Wiring Diagram; VME Timing
Module Schematic, Fabrication and Assembly. VME programmable timing
module front panel drawing
signed-off, PCB design/schematic proceeding. VME based MPS input card
front panel layout and PCB design
progress. VME Interface daughterboard interconnections are specified
and the PCB design is progressing as
well.
WBS 9 (Transport):
Dipoles
Injector Dipoles (DU/DV)
o DULY Research, using their magnetic model, probed the sensitivity
of their sliding shorts to the field clamps
solution to uniform field integral of the small
injector dipole. They found that changes of a mm keep the integral
within specification.
o They sent the complete package of drawings of the small injector
dipole (DV) to us for checking.
Arc Dipoles (GY, GX, GQ)
o AES was successful with new runs with the model of the 180 degree
Dipole with reduced strength path length
correctors. The good field region width was
expanded and the longitudinal field uniformity also improved
significantly. With a small change in the
bulk field obtained by adjusting the Purcell Gap, the parallel offset would
also fall into the sub mm values that are within
David Douglas’ specifications. Further work was halted until the
current and bulk field were appropriately matched
between this magnet and the Arc Bend (GX).
o They are continuing design and magnetic modeling the Arc Bend
Dipole (GX). Their results showed a
parabolic change in the bulk field of the
magnet, lowering by 7 parts in 10000 over the 0.6 meter central zone.
Consultations with David Douglas and further efforts
are on going to find out if this is acceptable, to see if we
experienced similar results with the IR Demo and
on determining just what Bulk Field really means when applied
to a real magnet.
o Design efforts concentrated on introducing the lead configuration
that allows powering the two sets of coil pairs
independently.
Quadrupoles
QX (3 inch quad)
o The coil manufacturing bids were received and the evaluation team
given the papers to start their process.
o The core procurement package remains out for bid.
o One of the added end chamfer shim configurations to the prototype
quadrupole showed promise in
understanding the reduction of the n = 10 pole and
another run with double the shim confirmed showed double
the results. We will now try a series of cuts
using this understanding to reduce both the n = 6 pole and the n = 10
pole. David Douglas has found that he can
live with the higher 3 part per thousand error of the original
configuration but is encouraging us to get a lower
value.
QT (Trim Quad)
o Design work continued.
Sextupole
o Robin Wines restudied the 2D design to understand further the
generation of a vertical corrector dipole set of
windings. She is now continuing to change
the model to 3D design in TOSCA.
General
o We anticipate a response today from the company that gave us
the Dipole Steel bid so that we can place that
procurement.
o We are now assembling the attachments for the task definition
to be used by an engineering service contractor
for design of the arc chambers.
o Jeff Karn gave us notice that he will be leaving the Lab on
the 20th of June. Robin Wines will take over
direction of the magnet effort and Tom Hiatt will
take over direction of Magnet Measurements.
WBS 11 (Optics):
The optical cavity assembly design has progressed in the following
areas: The movement of the gimbal mounts
has been converted from linear translation stages to precision rails
and ball bushings. We decided to reduce
some complication in the framing by attaching the rails to the side
of the vacuum enclosure. The gimbal assembly
support structure, which also supports the linear actuators and lvdts,
has been designed. We received quotes
and engineering details on another UHV motorized actuator. The
actuator surpasses our specifications, and
should integrate easily into our design. We are checking with
at least two other vendors to confirm the pricing is
competitive. We received a motorized actuator and will start
outgassing studies next week.
The following work was done this week to support Operations: Removed
optics diverting the drive laser beam
to the OBPM test stand. Aligned turning mirrors for the bypass
transport to the carbon anotubes experiment.
We received refigured, broadband (5.0 - 6.6 um) outcouplers, and are
inspecting them.
Operations/Commissioning:
Preparations continued for the summer user run including check-out
of diagnostics and LSS certification. We
also continued working with various groups in the Lab to help with
the re-certification of the ODH sensors. At
this writing the Safety Systems group has identified a recalibration
procedure that will allow the existing ODH
sensors to be recalibrated for the 18% oxygen concentration set-point.
This procedure will be attempted with
the ODH sensors in the FEL vault on Monday.