Aug 20, 1991 - Blue Sheet

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Project Progress Summary

August 20, 1991

FET Operations

  • One day was devoted to a continuation of work with the RF cavity autotune program.
  • One day was spent with alignment activities. The installed recirculatory stands are now aligned adequately for equipment installation, and the second 180-degre bend is well aligned, ready for connection of the vacuum system.
  • One beam run was devoted to a measurement of the cavity kicks from six cavities in Phoenix.
  • There is now good evidence that some noise problems are due to noise bursts on the 1427-MHz master oscillator signal.
  • The final beam run was spent doing performance measurements on the 1500-MHz BPM and the pulsed harp.
  • The 1500-MHz BPM was measured with CW beams of 1, 5, and 10 microamps. While further detailed measurements are required, these devices appear to work well. Further work is required on the pulsed harp.
  • Shut down operations 19 August for Injector recirculator installation and CHL activities by CVI.

WBS 1

Vertical Test:

  • Interlocks on dewars 3, 7, and 8 are complete. Dewars 7 and 8 have been checked out and run through their cycle.
  • The pressure control system for the dewar has been checked out. Conducted a pumpdown of a dewar and it worked well.
  • The automatic level set is operational in the RF system.

Pair Parts:

  • Continued progress on fabrication of pair parts.
  • Sixteen elbows were finished, cleaned and are ready to be leak checked.
  • Production QA route sheets have been prepared and are being reviewed.

Window and HOM Loads Production:

  • Preliminary production plans exist for both HOMs and RF windows. These plans provide for the initial completion of the first cryomodule in November, while procedures are being qualified for full production. These plans call for the delivery of 50-60 HOM loads in early October, with ten window assemblies being delivered by mid-October. Full production should begin 1 November.

HOM Development and Testing:

  • Change Request for beam current threshold in accelerator based on present loads has been approved. Beam current threshold of the HOM loads is reduced from 14 mA to 4 mA.
  • Received five tiles of AlN-glassy carbon from Ceradyne. Measured the dielectric constant and loss tangent of the tiles. They have been returned and received by Ceradyne. They will be cut into loads by 30 August.
  • Five stainless steel flanges have been electropolished by Alexandria Metal Finishers and are being returned.
  • Leak test apparatus is now operational with outgassing problems resolved. Tests will be performed next week.
  • The position of the ceramic absorbers on the flanged remains as in the previously produced loads, since it provides optimum absorption at approximately 3 GHz.
  • Tested HOM loads on quarter0cryomodule for damping. Found major modes fall within external Q specifications.

Cavity/Cavity Pairs:

  • Finalizing first draft of cavity assembly travelers.
  • New alignment fixtures are being evaluated.
  • The coordinate measuring machine is being updated to make more cavity measurements.
  • IA89/101 has been tested at 2 K by I. Campisi. The test confirmed the results achieved on 7 August.

Cryounit/Cryomodules:

  • Work is being done on improving production tuners.
  • Continuing permeation tests of warm windows.
  • Work is being done on upgrading tooling for the fourth cryounit assembly line.
  • Three cryounits and end cans have had the interconnecting primary circuits and beam line connected for the next cryomodule.
  • Work has started on cooldown and warmup area in cryomodule staging area.
  • One and one-half cold cycles have been successfully completed on the quarter-cryomodule in the test cave.

WBS 2

Mechanical:

  • The first twelve of the 112 required 3-meter arc dipoles (Bas) were received from Process Equipment Corporation.
  • The best and final offers were received for the arc quadropoles (QAs), linac quadrupoles (QBs) and the linac corrector dipoles (BTs), and awards were determined, subject to DOE approval.
  • Proposals for the arc correctors were received and are in evaluation.
  • Full conceptual requirements for all septa were established and the process of converting them into engineering reality was started.

Alignment:

  • The drawings for the production alignment fixtures for wuadrupoles were signed off.
  • A skeleton network for the tunnels in the beam switchyard was installed and measured
  • The second 180-degree bend of the recirculation experiment was aligned for hookup.

Installation:

  • The contract to install the west arc stands was awarded to Bruce Corporation.
  • A new style of fork truck with lower height and single-wheel steering was evaluated in the tunnel for the task of stand installation and found to be very suitable.
  • A gantry crane was set up in the south stub of the east arc to utilize the space as a storage buffer area for installation.

WBS 3

  • A meeting was held at Varian on 13 August, with conference calls on following days. Details regarding warranty, delivery, processing, etc. remain to be worked out.
  • Fabrication of 26-ft coaxial cables has begun at Blue Crab operations. Phoenix Logistics has shipped all SMA type connectors. N-type are due next week.
  • Arc/IR cables will be assembled at Blue Crab because outside contract was cancelled due to contractor nonperformance.
  • First articles MOPS (Golden Assembly) and power distribution (EDL) required minor rework. Six power distribution chassis were received Friday. Two more MOPS are due next week.
  • First-article video board was received and QA’d. Small quantity of assembled boards was expected Friday. Twenty-five boards are due 21 August.
  • First article of midplane/rearplane was shipped last week, with four more due next week.
  • The contract for IF and analog board assembly was awarded to RMS Technologies of Newport News. Twenty-five first-article boards are due this week. Arc detector logic boards and backplane boards were ordered. Delivery is to be 21 August.
  • Klystron 3, INO3 does not make rated cathode current at specified filament voltage. It is slated for replacement next week. Klystron 1, IN04, is also slightly low and is being investigated. A full calibration of klystron DC monitoring points is planned. Filament boards in IN03 and 4 will be changed and modified to limit inrush to 7 amps, per Varian recommendations. Plan to run extended hours on 16 klystrons, plus on/off filament cycling on one additional unit.
  • Airflow was tested in second article of air duct for low-level rack cooling.
  • Installation of HPAs was started in the south linac.

WBS 4

  • Cable pull for WBS 7 in south linac is in progress.
  • One trim rack system has been placed in position in the south linac. This brings the total trim rack installation to 17.

WBS 5

  • Equipment list is being updated and database created.
  • Problem status tracking report will be published each week with software group minutes.

WBS 6

  • Replies have been received from the potential vendors to the first round of questions on the Hall C quadrupoles.

WBS 7

  • Shipped another section of transfer line to the tunnel.
  • General preparations for the shutdown.
  • Completed expansion box #13 for the return transfer lines.
  • Started work on the cold box #4 for the CTF.
  • Working with CVI on the 2-K cold box commissioning.
  • Computer revisions will start Wednesday.
  • CVI observed the 2-K simulation model 16 August.

WBS 8

  • Continued preparatory work for installing crane rails in Hall A. Also started to clean up in this hall in preparation for final punch-list inspection of the structure.
  • Stated installing shoring in Hall B to support dome concrete placement.
  • Continued installing reinforcing steel for the Hall C dome. Placement of the concrete dome is scheduled for Wednesday, 21 August.
  • Backfilling continues in all areas when weather permits.
  • MCI continued excavating, forming, and placing ESR building footings. They also installed precast concrete pipe sections for the ESR cold box pit.

Support Services

Stockroom:

  • All of WBS 3 electronic kits are complete with the delivery of 324 I/O and CPU boards.
  • Activity for the week: $33,130.71.
  • Activity for the month: $68,796.45.
  • Moved 20 racks from EEL to south linac and three control racks from north linac to Blue Crab.

External Fabrication:

  • QC’d HMS detector plates for Hall C at vendor; fabrication looks acceptable.
  • Processed purchase requests for:
    • Ball screw assembly for recirculatory
    • Miscellaneous components for vacuum support

Technical Illustration:

  • Developed figures for ESAAB presentation.
  • Developed 12 color titles for SRF and FEL conference which featured a standard CEBAF logo appearance.

RF Superconductivity Workshop

P. Kneisel, C. Reece, G. Myneni, K. Saito, and J. Susta are attending the “5th RF Superconductivity Workshop” this week at DESY, in Hamburg, Germany. P. Kneisel is giving a talk on “Improvements in Material and Fabrication – Large Scale Production and Testing.” Several CEBAF posters are being presented:

  • “Mechanical and Thermal Properties of High RRR Niobium at Cryogenic Temperatures,” G. Myneni and P. Kneisel.
  • “Observation of Q-Degradation in Superconducting Niobium Cavities Due to Cooldown Conditions,” K. Saito and P. Kneisel.
  • “Some Detailed Investigations on Indium Joins,” G. Myneni and P. Kneisel
  • “Sensitivity of CEBAF 5-Cell Cavities to External Pressure,” P. Kneisel, A. Heidt, J. Mammosser, and G. Myneni.
  • “Present and Future Trends in Cryogenic Instrumentation,” G. Myneni.
  • “Behavior of an Electropolished Niobium Cavity Under Different Cooldown Conditions,” K. Saito, E. Kako (KEK), P. Kneisel, S. Noguchi (KEK), and H. Miwa (Normura Plating Co., LTD).
  • “A Closed Cycled Cryogenic System for Testing Superconducting RF Cavities.” C. Reece. J. Susta, T. Powers, and B. Almeida.
  • “An Automated RF Control and Data Acquisition System for Testing Superconducting RF Cavities,” C. Reece, T. Powers, and P. Kuchnick.

FEL Conference

J. Bisognano, F. Dylla, P. Liger, G. Neil, D. Neuffer, and C. Sinclair will attend the 13th International Free Electron Laser Conference in Santa Fe next week. CEBAF papers for the conference are:

  • “A Bunching Scheme for FEL Applications at CEBAF,”