View source for June 11, 2013 Solenoid Meeting

Thursday June 6,2013 at 11am 
At Jefferson Lab, the meeting will be held in room CC F324

== Attendees ==

== Agenda ==
* Discuss last weeks minutes https://halldweb1.jlab.org/wiki/index.php/June_6,_2013_Solenoid_Meeting
* Status of Action Items
# Incorporate quench detection balance/tests into the 140A procedure (Rev C) - George  [[Media:140A procedure.pdf]]
# Update hardware QD with dial pot and PLC with inductance algorithm - Elliot
# Add full resistance measurement and acceptable value to 140A procedure - George
# Identify all known buggers in the procedure for approval - George
# Clean up refrigerator and get ready for cooldown - Jonathan
# Determine if turn to turn short could have caused quench in coil 1A - Eugene
# Determine what is a safe current to run at using the existing refrigerator - all
# <strike>Set up a meeting with all parties to get agreement on the path forward - Tim</strike>
# Write up determination of what it would take to catch a quench once it starts - Probir/George [[media:Quench propogation.pdf]]
# Write up final analysis of quench (suppositions) - George/Eugene
# Write up high current portion of procedure (Rev D) - George
# Balance Power supply for 25H - Giles
# <strike>Order 2 additional burst discs - Tim</strike>
* Do we go right into high current from 140A if ready?
* Path Forward .......

== Useful Info ==
* Documents available at M:\halld_engineering\Solenoid\Commissioning\Response to Quench

== Meeting Minutes ==

We discussed the results of last week's meeting and the proposed path forward. We went through Probir's margin comparison for different currents and temperatures as well as George's latest 140A commissioning procedure. Also discussed, was whether or not the quench could be caught. It appears that the answer is no. Once it starts, at least 1 coil will completely quench based on Probir's analysis.
A discussion on the required tuning of the power supply for 25H was required for the 140A and full current testing revealed that it may not be necessary for the commissioning if the smooth ramp profile keeps the voltage spikes below 300mA. The data from last week's warm ramp up will be reviewed and additional ramp tests at lower rate changes will be performed warm if necessary.Eugene did not want to make the tuning changes if we did not have to.
Jonathan brought forth the suggestion to bring a signal from the refrigerator if the compressors go down or other catastrophic event happens that the magnet will immediately fast dump. This is being incorporated. The refrigerator is still being cleaned and may be ready to cool down the magnet early next week. 
Discussion on the allowable margin to run the magnet safely yielded the following; It should be assumed that the quench of the magnet last month should be the new zero point. The new maximum running current should yield a calculated margin of at least 0.4K above the new zero (or 0.9K above Alcorn's spec). This applies to whether or not a dewar is attached. Probir will calculate what temperature is needed to run at 1500A with this margin.
Discussions on the adequacy of the existing dump resister determined that the current dump resistor is adequate and changing will not necessarily help.
It was also recommended that we ramp up in steps when we near higher currents to check the temperature stability and voltage. George will add this to the full current commissioning procedure.
The path forward was also discussed and it was generally agreed that we would not start cooldown until we have a preliminary write up outlining the results of the quench analysis (including turn to turn short), dump resistor determination and maximum current/margin rationale. The 140A procedure should be approved this week and a preliminary high current run procedure by next week.

== Action Items ==


== Path Forward ==

# 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 14)
# Continue repair of refrigerator (to be completed by June 17)
# Write preliminary analysis of quench and rationale for dump resistor and max current (June 17)
# Review of preliminary write up by Bill Schneider and Bob Flora (June 19)
# Fill magnet with liquid (to be completed by June 23)
# Complete and sign off maximum current plan and quench analysis(Same OSP- New procedure or New OSP?)(to be completed by June 23)
# Perform 140A testing ( to be completed by June 28)
# Perform High current commissioning ( to be completed by June 30)
# Map magnet (to be completed by July 3)