Nov 19, 1991 - Blue Sheet

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Project Progress Summary

November 19, 1991

FET Operations

  • This was the second week of 11 shifts of beam and 17 shifts of RF running. Reliability was good with beam available on most occasions per schedule.
  • Beam energy spread reported last week was based on calculated dispersion in the 180° bend. This number was preliminary, and the actual upper bound on the energy spread may be larger. Work is underway to tie this down.
  • Progress has been made on recirculation, but further work remains in getting properly focused beam all the way through on a second pass. Some second-pass beam has been observed at the exit of the second cryomodule on BLMs.
  • Initial testing was performed on the emittance measurement procedures. They appear to work correctly, but testing is required.
  • Preliminary bunch length measurements were performed using the Yao cavity. This needs to be repeated due to nonlinearity in the response.

SRF

Cavity Pairs:

  • IA90/IA91 was transferred to the cryounit assembly area.
  • IA129/IA130 was assembled Monday. Maintenance, filter replacement, and water quality checks are being done on the main chem room DI water system.

Cryomodules:

  • The cryounit technicians completed the 4th cryounit for cryomodule #8, and preparations have begun for transfer to the cryomodule assembly area this week.

HOM Loads:

  • Four HOM loads turned over to the cavity group. The final braze was completed on 22 additional loads, giving a total of 52 production loads completed to date.
  • Received several batches of final machined flanges that will be shipped for electropolishing. Over 100 loads will be available for final brazing by the end of this week.

RF Windows:

  • Twenty-five windows have been electron beam welded and are ready for RF testing and final inspection.

Arcs

Magnets:

  • Sixteen dipole support bridges were installed in the east arc.
  • First article coils were approved for linac correctors (BT) and 2" quadrupoles (QB).
  • Redundant rechecks of the chemistry of the arc dipole steel showed the material is acceptable.

Survey/alignment:

  • East arc stand alignment complete. Bridge alignment underway.
  • Level checks in the BSY and Hall C have found a 12 mm settling since the last survey in the summer.
  • A route for the end station cryo line has been staked out.
  • Another fixture was mapped for SRF.

DC Power:

  • One trim rack placed in El. Total is now 30.
  • The east arc cable tray installation is a bit beyond the 50% point.
  • WBS 1 cable pulls completed in south linac section 3.
  • East arc cable tray installation is ongoing. The east arc box supply return cable installation was started.
  • Relabeling of breaker panel boards, per request of safety personnel, was completed.

Diagnostics:

  • Visits were made to the BPM vendors.

Linac

Ops Electronics:

  • FET CARM (radiation monitor) network communications completed. Boundary monitor 50% complete.
  • Stability tests of 100 MHz BPMs show no drift for periods> 1 hour.
  • Installation of south linac diagnostic and control racks started.

Cryogenics:

  • CVI scheduled to return early this week to get ready for acceptance test.
  • Cold box #4 for the CIF is set in place and final preps for connections to the system are in progress.
  • Cryo has supported FET and VT A as required.

Physics

  • Bids were received last week for the photomultiplier (PMT) contract for the CEBAF Large Acceptance Spectrometer (CLAS) time-of-flight system.
  • Hall A will issue their call for best-and-finals (BAFOs) for their dipole coil/cryostat contract this week. Contract award is planned for January 1992.
  • BAFOs for Hall C quadrupoles are in final evaluation.
  • The "Detector Meisters" completed the construction and testing of the one-sided readout system proposed for the Hall B prototype calorimeter. Results were good, and a two-sided prototype is now under construction.

Civil Construction

End Stations Underground (Package A)

  • Continued working on cleanup, leak repairs and punch list items in all areas.
  • Hall B cleanup is essentially complete, and a punch list will be developed this week.
  • Completed installing the crane support brackets and started installing the crane rails in Hall C.
  • Completed the storm drain system, site fine grading, roads, and parking lot work.
  • Robert Gay Construction Company is demobilizing and has moved its office trailer off the site.

End Stations Above-Ground (Package B)

  • Continued working on site utilities and the footings and underslab utilities for SB #1.
  • Completed the slab on grade for SB #4. Erecting the structural steel.

Miscellaneous Projects

  • Held preconstruction meetings with Qualicon for the Floor and Floor Plate Assembly subcontract in Hall A and for the Instrument Air, LCW Piping, etc. subcontract in the accelerator tunnel.

Support Services

Stockroom:

  • Withdrawal activity for the week: $17,087.72.
  • Total monthly expenditures: $36,196.94.
  • Stockroom will be closed for walk-in withdrawals the first two weeks in December for complete inventory. Electronic ordering will be available.

Machine Shop:

  • Fabricating two alignment carrying racks for Quad Reference Fixture and two racks for Arc Dipole Reference Fixture for WBS 2.
  • Fabricating fourteen pick-up coils and two Z-field coils for Physics.
  • Manufacturing two fixtures to align the bellows and dish to the cavity for WBS 1.

CEBAF Science Series

The next CEBAF Science Series presentation will take place Wednesday, 20 November. Professors Hans von Baeyer and John McKnight of the William and Mary Physics Department will re-create in authentic detail an eighteenth-century science demonstration. Students in grades six to twelve are targeted for the Science Series, but all are welcome. Professional closed-circuit TV coverage will be provided in the lobby for high-quality viewing by overflow crowds.