June 25, 2013 Solenoid Meeting

Thursday June 25,2013 at 11am At Jefferson Lab, the meeting will be held in room TED 2504

Attendees

C. Rode, T. Whitlatch, E. Wolin, B. Flora (via Skype), E. Chudakov, J. Creel, G. Young, P. Ghoshal, George Biallas, Bill Schneider, Javier Gomez

Agenda

• Discuss last weeks minutes https://halldweb1.jlab.org/wiki/index.php/June_20,_2013_Solenoid_Meeting
• Status of Action Items

1. Release 140A procedure (Rev C) - George Media:140A Rev C.pdf complete
2. Update hardware QD with new 10 turn pot and PLC with inductance algorithm - Elliot In work
3. Clean up refrigerator and get ready for cooldown - Jonathan - In work
4. Finalize write up of quench analysis, dump resistor and max current rationale - George In work
5. Continue low current ramp tests to categorize voltage spikes - Giles - In work
6. Write up high current portion of procedure (Rev D) - George Media:High Current Rev D.pdf1st cut out
7. Balance Power supply for 25H (if necessary based on 140A tests)- Giles In work- Parts received from Danfysik
8. Calculate what current we can safely run at at 5K 0.9K margin. Media:5K Quench Margins.pdf Complete
9. Set up meeting with Patrizia Tuesday for cooldown decision. Complete

• Are we ready to start cooldown?

Useful Info

• Documents available at M:\halld_engineering\Solenoid\Commissioning\Response to Quench

Meeting Minutes

Discussed minutes from last mtg. With the new power supply ramping procedure, we see no voltage spike on going from zero current.

The current is lagging behind what it should be during the programmed ramp up. May be due to resistance in magnet with PS set to inductive or the PS not balanced to 25H. Will do further testing without magnet hooked up. Possibly change algorithm.

Bill Schneider raised question of 1360A with dewar is slightly below .9K margin. Do we wish to do it?

Discussed the timing of the cooldown and testing - see "Path Forward" section below. Jonathan working on plan to allow liquid levels to drop to allow more time for superconducting testing.

The minimum current for commissioning should be 1200A (by Aug 9)- do we do a full mapping at this current?

Tuning PS to 25H - Decided to borrow a spare board from Hall C sister PS and test in our PS. If it works, modify the spare board according to Danfysik instructions. When it is ready, make decision on whether or not to implement.

Decision to change allowable voltage rise in the hardware QD to 500 mv. Also, the software QD integration time will be increased to 250msec for 100 mv limit. George will update rev. D of the procedure with high current running and these QD limit changes.

Probir calculated the max current at which we can add a Dewar to the system based on a 5K limit (with .9K margin). This would be 1200A

We discussed the pressure rise possibility during a fast dump. George will look at what happened at the 1260A fast dump from the heim column limit. Discussed adding a pressure relief solenoid valve for operations to keep the temp in the coils low if there is a refrigerator event. This will be looked at later for physics operations.

Decided to start field mapping the beam centerline location at 1000A - calibrate the hall probe using the NMR

Use 60hz filter for GFD as suggested by Bob Flora.

New Action Items

1. Release High current procedure (Rev D)with discussed changes by July 1- George
2. Update hardware QD with new 10 turn pot and PLC with inductance algorithm by July 1- Elliot
3. Clean up refrigerator and get ready for cooldown by July 3 - Jonathan - In work
4. Finalize write up of quench analysis, dump resistor and max current rationale - George In work
5. Continue low current ramp tests to categorize voltage spikes/current lags - Giles - In work
6. Check pressure rise during 1260A heim column fast dump - George
7. Get spare Inductance balancing board from Hall C and test in PS and modify if it works - Giles
8. Make decision on whether or not to install new PS balance hardware - Eugene
9. Make decision on starting refrig cooldown be July 3rd - Jonathan

Path Forward

1. Complete the 140A procedure including the quench balance and turn to turn short check not completed in the 15A test (to be completed and signed off by June 24) Complete
2. Continue repair of refrigerator (to be completed by June 25)
3. Update preliminary analysis of quench and rationale for dump resistor and max current (June 25)
4. Initial review of updated write up by Bill Schneider and Bob Flora (June 26)
5. Start refridge cooldown (to be started June 26th if agreed upon)
6. Complete and sign off maximum current plan and quench analysis(to be completed by June 29)
7. Start cooling magnet - July 8
8. Perform 140A testing ( to be completed by July 21)
9. Perform High current commissioning ( to be completed by July 23)
10. Map magnet (to be completed by July 28)