Project Progress Summary
September 10, 1991
FET Operations
- Recirculator installation has progressed substantially. All stands are in place with alignment step 2 complete (for hookup). The mechanical installation is nearly complete, with some additional work needed on the energy recovery stand. About 50% of the system is under vacuum. Most cables are terminated, and magnet operation is beginning.
- New emittance-defining apertures, which will permit operation at full beam current, were sent out for brazing this week, and will be installed on their return in a few days.
- 100-kV DC beam, with 100-MHz current modulation applied at the gun control electrode, was delivered for a test run with the 100-MHz BPMs Friday evening. There was finally adequate 100-MHz modulation for the BPMs to function. However, work remains to be done on these monitors.
WBS 1
- Ceramic order (quantity = 60) for RF windows expedited for preproduction qualification. These will be machine and metallized. Delivery expected 30 September.
- New order (quantity = 340) for production window ceramics placed with Astromet.
- The Anti-Multipacting Coating Committee met last Friday and unanimously selected chrome oxide as the anti-multipacting coating for the ceramic window. They also adopted a set of procedures. Initial measurements of chrome film sputter deposited ceramic window material showed good results.
- Fifty HOM flanges with inserts have been received and will be brazed this week.
- Ten complete sets of AIN-glassy carbon absorbers were received. Ground two each from a set of five tiles. The dielectric constant and loss tangent were measured for each piece (2) of each set and found to fall within Epsilon 20-24 and loss tangent .13-.17 at 2100 MHz. The absorption characteristics of the unbrazed sets were measured, giving return losses of > 10 dB at 2.1 GHz and with repeatedly uniform curves. This constitutes good performance.
- Ceramic tiles have been received and are being tested for dielectric constant and absorption effectiveness. These tiles will be used for production startup and procedure qualification.
- Cavity pair parts continue to be formed, machined, and welded.
- Work continues to prepare the cryounit area for the fourth production line.
- Modifying the ball screw shafts of tuners for fit of ball bearings.
- Working on the warmup/leak checking staging area for cryomodules. Presetting flapper valves for the cryomodule insulating vacuum protection.
- Four cooldown/warmup cycles completed on the quarter-cryomodule thermal cycle test. The second desorption test is being done.
WBS 2
Magnets:
- Thirteen 1-meter dipoles (Bes) were brought to the accelerator tunnel to await installation on the dipole stands after passing all qualification tests and inspections in the test lab magnet measurement area.
- The first two production versions of the linac quadrupoles (QBs) were measured for magnetic quality and met specification.
Survey and Alignment:
- As-built surveys of the beam switchyard tunnel and End Station A were started.
System Integration:
- The song sheets that include the second spreader were competed. This includes sheets for the tunnel enclosure, accelerator elements, and cooling water distribution.
WBS 3
Controls:
- Ran calibrations on the first five control modules in the test stand at a single temperature, and downloaded the calibration coefficients to the on-board memory. The total time was 2.5 hours per module – quite reasonable. When we get software version 17 running, it will be somewhat easier.
- Production IF control boards boards are being delivered.
- Software version 17 passed the bench tests. It will be installed in the injector modules.
RF Power:
- Fourteen more HOM filters from Gamma Microwave are in incoming inspection.
- We hae tested a Varian klystron to in excess of 1300 on/off heater cycles without failure. Varian and CEBAF are near agreement on the klystron specification change, and we expect shipment of klystrons to start within a few days.
- Klystron power supplies with the newly installed line reactors are running somewhat hotter than original units (due to dissipation of reactors). We will look at some forced ventilation for the cabinets.
Fabrication:
- The cable shop is building the 26-ft ¼-in. RF cables. The first batch was checked on the network analyzer and looks good.
- Shipped two sets of control racks to the north linac for installation.
WBS 4
- Finished cable pull south linac service building for WBS 7.
- Completed cable pull for WBS 5 from MCC to W1 service building.
- Placed third trim rack in south linac service building, bringing the in-place total to 20.
- Completed installation of transformers and breaker panels in north and south access buildings for powering trim racks.
- Awarded contract for CAMAC scanner modules which will be used to communicate with power supplies.
- Completed rack end termination of load cables and most magnet terminations for recirculatory trim rack.
WBS 5
- Version 17 support has been under way, as ha been conversion of the injector.
- Tests of SLAN are under way to determine signal loads and response times to get data to support the TACL review scheduled for 17 September.
WBS 6
- The Hall B tagging magnet subcontracts are on schedule. The iron portion was awarded to Inland Steel last month, the machining contract for the steel was awarded 3 September, and the coil contract is scheduled for award on 23 September. Components will be delivered by next July when assembly by the Hall B staff and users will commence.
- Bids are in hand for the Hall A floor plate contract.
WBS 7
- The northwest linac 4-K return transfer line is completely welded. Vacuum pumping for the leak check has been initiated.
- Expansion box 15 has been completed.
- Rework on the shield test heater for the CHL has been initiated. This will allow CVI and FET to operate simultaneously for CVI’s preliminary runs prior to the acceptance test.
- Final leak check in progress for the southeast quadrant.
- A standard section of return transfer line was placed in the northeast section of the linac this week.
- CVI is progressing, but problems locating the low-pressure return leak in the 4-K box have hampered progress.
- CVI is also attempting to correct the thermometer problem.
WBS 8
- Continued cleaning and installing crane support in Hall A.
- Completed dome shoring ribs in Hall B. Now installing the decking which will support the concrete.
- Began post-tensioning the Hall C dome.
- Temporary structures have been installed at the exit stair and counting house grade-level entrances.
- Backfilling continues in all areas when weather permits.
- MCI continued excavating, forming, and placing ESR building footings and SB #4 footings. Completed half of the ESR retaining wall.
Support Services
Machine Shop:
- Completed upgrades to FET model which included the chicane table, waveguides, and beam pipes.
- Fourth recirculatory QB magnet ready for assembly today.
- Beam transport girder prototype is in process.
Technical Illustration:
- Updated evacuation plans.
- Revised Hall C plan and elevation views.
External Fabrication:
- Input magnet support brace for first 180-degree bend assembly into machine shop.
Stockroom:
- Weekly expenditure: $15,854.39.
- Barcode hardware and software being acquired.
Document Control:
- Mass production copier (OCE') will be shut down over weekends; arrangements can be made.
Quality Assurance
CEBAF is preparing to issue a request for bids for an instrument calibration subcontract.
Until this contract is in effect, instrumentation should continue to be calibrated on an
individual basis, using the normal purchase request system.
Computer Center
- On Thursday, 12 September, CEBAF7 will be down all day for reconfiguration as a boot node for the LA VC (CVS00l/2/4/5/6/8).
- On Tuesday, 17 September, the entire Cluster (CEBAFl/2/6/SMICROl/ACCELl) will be down from 8:00 a.m. to 10 a.m. to install a new tape drive unit.
CEBAF Colloquium Series
- On Wednesday, 18 September, at 4 p.m. in the auditorium, Gail_ Hanson of Indiana State University will discuss "New Results from LEP."
CEBAF Science Series
- The flyer for the Fall 1991 CEBAF Science Series is being distributed. The first presentation will be held Wednesday, 25 September. Students in grades six to twelve are specifically invited, but others are also welcome. The Science Series seeks to bring students who like science together with scientists and engineers who are gifted at bringing out the fun and enjoyment of science, technolgy, and math careers. Please see the blue flyer for details.