Injector Test Stand Meeting Minutes of November 19, 1996

and Reports of November 22, 1996

AGENDA:

General Announcements

Action Items

Progress Toward the Milestones of the enclosed schedule:

NOTE: Meetings are held every Tuesday in CEBAF Center, Room #A110, at 11 a.m., unless otherwise notified.

ATTENDEES: M. Augustine, S. Benson, J. Bennett, G. Biallas, C. Bohn, J. Fugitt, D. Guilmet, K. Jordan, R. Legg, G. Neil, C. Piller, M. Shinn, T. Siggins, J. Song, R. Walker, M. Wiseman

NOTE: A reminder to all principals to submit a brief weekly progress to D. Gilchrist each Friday by noon

General Announcements:

None

Decisions/Comments:

The plan for ceramics is to obtain two usable assemblies of insulating ceramics with the lower bulk resistivity (3 % glass-aluminum oxide) bodies now being prepared. Toward that end we will make three ceramics using each bleed coating style, two for each assembly and one spare.

We are now coating three bodies with the first style, used on the original ceramics. The Chrome Oxide/ Vanadium Pentoxide, high-fire coating has exhibited non uniform resistance outcomes where manufacturing variables were held constant. Each of the first coatings exhibited extrapolated resistances at operating voltage that were two to three orders of magnitude higher than planned and at the same time, were not within an acceptable factor of 1.5 from one other. The second spraying and firing of one, lowered resistance by an order of magnitude. We are attempting to match it by doing a second spray and firing on a second body of the style. If there is a close match, we will use the resulting pair immediately in an assembly, thinking that the admittedly high resistance is marginally acceptable to drain any calculated field emitted charge and still establish a reasonably uniform field gradient across the assembly. We will also give a second spray and firing to the third body of this series, attempting to obtain a good resistance match to the other two. (or it may turn out to be a better match to one of the first two, we will attempt to use it for the assembly).

We are now allocating he remaining three ceramics to the ion implantation process which is under development. We believe this process promises to be a far more controllable process than the fired coating and far more quickly achieved. The Rotisserie is now ready and will be air shipped to Lawrence Berkeley Lab. A trial ceramic from the original bodies will be implanted first, to establish a procedure. It will be followed by implanting all three. Lab samples indicate the proper resistance can be obtained by several hours of exposure to the ion beam.

Safety Action Items:

K. Jordan - Add a third sensor for ODH to the High Voltage room. Almost complete, part on order. Decision to put it high in a corner.

J. Fugitt, C. Reese, K. Jordan - Review the safety effects on our systems of running only one HPA for work in the Cryomodule Test Cave. In process but not needed until at beam is used in the cryomodule. No progress.

RCG - Review the beam containment policy and the Machine Protection System during October. R. Legg reports he is waiting for RCG action. Now in R. Legg's court to call a meeting.

New Safety Action Items:

Rich Hill - Label the gas lines - No progress

G. Biallas - Provide safety hardware for the shelf by the LCW system. No action.

M. Shinn - Excess boxes on cabinets. Not complete, but lots of cooperation.

Completed Safety Action Items:

R. Legg - Post doors with No Exit signs - Judged by everyone as confusing. Dismissed.

Action Items:

G. Biallas - Make a new ceramic stack and make a new cathode support tube with a anti field emission coating. See Discussion and weekly report by G. Biallas.

Determine the need for additional personnel required to match or beat the Schedule. If we don't get the ceramics done for a December change-over, we will miss the use of alignment and installation personnel and in January and February because of planned Accelerator shut-down and Physics activities.

G. Biallas - Finish the LCW System: Flow & Temp reading, Level indicators, Full qualification walk through needed. Remove two carbon steel pipes inside LCW system. J. Fugitt wants to check calibration on the conductivity gages. Walk through will be tomorrow.

K. Jordan/S. Benson - Failure analysis for the 10 MeV beam handling. Required by Dec. 1. No show stoppers showing up. Needs MPS controls on Conoptics modulators from EPICS working. Test will be sometime this week.

R. Legg - Write the OSP for the 500 keV Experiment with chopper on and cryomodule in the cave. and for the 10 MeV Experiment. Continuing.

M. Shinn - Define a secure procedure for turning on the Drive Laser from the control computers. Software in process.

G. Biallas - Get the strong back certified to lift blocks by Nov. 1. Block area being prepared.

L. Dillon Townes - Get the layout drawing for the installation of the off line Quartercryomodule signed off. Almost ready for signature. M. Wiseman will get it to Fugitt & Vignato in L. Dillon-Townes absence.

J. Preble - Get the ceramic windows finished for the December Quartercryomodule tests. One is on hand Two more may be ready by Friday for testing in the resonant ring test.

G. Biallas - Plan on what blocks to lift out for November change out. Quarter cryomodule will just fit by 6 inches within the width of the cave if it is lowered in through the gap left by two ceiling blocks. The downbeam most two of the five removable blocks are the candidates along width the three blocks above them. M. Augustine will move whatever is on top of them.

Biallas/Siggins - T. Siggins to try out Solenoid in order to verify it fits on Chopper. Will be done today.

K. Jordan - Design a new viewer system with stable cameras and appropriate windows. At the same time avoid stray light back to the Cathode. will be done during change-over.

K. Jordan - Substitute stainless steel for the aluminum filament supports on the harps. k. Capek is ready to do this during the change-over..

M. Shinn - Perfect the optical chopper before the next CW run. Needs refinement for more demanding runs. The 360 modulator has just arrived.

G. Biallas - Get drawings prepared of the configuration of the gun for the control room and a summary package that can be sent to others as an explanation of what the gun is. G. Biallas will attempt to get M. Zarecky to pull it together.

L. Dillon-Townes - Get the dump body flow tested. No action. Needs to be restricted to limit velocity below 10 ft. per sec.

K. Jordan/M. Shinn - At Change-over, install a method of characterizing the optical transport line configuration at any one time and conveying the information to operators.

All principals - Define the tasks for the change-over down and convey them to D. Walker. to get a master list going. D. Walker will hold a meeting to pull the items together sometime this week.

L. Dillon-Townes - Get the core for the solenoid before the Quartercryomodule for the 10 MeV Run. No progress reported.

G. Biallas - Identify and sequester the raster magnet for 10 MeV as well as all the remaining magnets. All magnet except the sextupole are sequestered. We will use a three horsepower three phase motor Stator. It is in the Magnet Test area for characterization. We will need low voltage three phase power.

New Action Items:

R. Legg - Check the alignment accuracy specs. of +- 1/3 mm for the Longitudinal experiment and the 10 MeV experiment.

L. Dillon-Townes - Convene change control board to make a recommendation on the Differential Pump Station and the question of baking the after Cryomodule line in both the ITS and the IRFEL after doing the necessary calculations of assumed gas load.

K. Jordan/R. Legg - Convene a working session in December on control software for the 10 MeV Run.

New Action Items for the Diagnostic Mtg.:

None

Completed Action Items:

R. Legg - Calculate the field necessary for the raster sextupole for the 10 MeV Line. Complete. A standard SB Sextuple should do it.

Individual Reports of 11/22/96:

Bob Legg:

All three ceramics (Serial #1, #6, and #2, in that order) have now been sprayed a second time in an effort to drive their conductivities to a range where we are sure the field-emitted current will drain off and the uniform gradient will not be altered excessively. The vendor in California has had a difficult time taking reliable measurements to determine if their resistivities match. The measurements are sensitively affected by atmospheric conditions, and they have been complicated by rainy weather and a damp atmosphere. At week's end a retest of #6 after heating in an oven and purging with dry nitrogen showed that its resistivity matches that of #1 to within 20%, an improvement over the previous test which showed a 100% difference. We are assessing whether to do a final qualification test using vacuum facilities here at Jefferson lab prior to brazing the rings.

G. Biallas:

All three ceramics (Serial #1, #6, and #2, in that order) have now been sprayed a second time in an effort to drive their conductivities to a range where we are sure the field-emitted current will drain off and the uniform gradient will not be altered excessively. The vendor in California has had a difficult time taking reliable measurements to determine if their resistivities match. The measurements are sensitively affected by atmospheric conditions, and they have been complicated by rainy weather and a damp atmosphere. At week's end a retest of #6 after heating in an oven and purging with dry nitrogen showed that its resistivity matches that of #1 to within 20%, an improvement over the previous test which showed a 100% difference. We are assessing whether to do a final qualification test using vacuum facilities here at Jefferson lab prior to brazing the rings.

Regarding other progress, we decided to ship the rotisserie for ion implantation to LBL and sent it by air freight. The new mid-voltage ring for the stack is being polished at 9 micron diamond grit on one shift. The samples of ion-implanted aluminum oxide coupons provided by LBL need to have come conductive paths on their edges removed by bead blasting.

J. Fugitt:

The DC power supply for the 8 KW klystrons is back on the street. We have given the vendors a short time for responses.

The low level racks are complete and tested ( with a short punch list).

The 600 KV power supply tank budgetary quotes came back and are within budget.. Minor changes are being made to the drawings, then we will get the final quotes. Delivery expected is 12 weeks.

The waveguide flex couplings are going back out for BAFO. One of our vendors did not understand our drawing.

R. Walker:

When a 10 dB waveguide coupler is located, the Chopper cavity will be driven by the Buncher klystron via the coupler. This will provide up to 450 watts to the cavity.

The Buncher water skid is being modified to provide a cavity temperature and improved water flow. A replacement valve for the water skid is due.

The remote control and status signals are defined for the entire RF system. New downloadable code and screens will be available in a few weeks.

The 2nd request for bids is "on the street" for the new 225 KW variable power supply. Replies are due 3 December.

The new low level RF racks were tested this week in SL21. The results were good with only a short punch list of minor deficiencies.

The waveguide flex couplings are back out for BAFO. One of the vendors did not understand our drawing for this part and a modification was made to it.


Enclosures:

ITS Schedule for 11/26/96