80K shield is down to <60K Liquid level not building. Power leads rippling and warming. T1 inlet 85K with 10%heater load. Lowered the set point of TI121 to 17K. Shut off flow to the 80K shield to try and warm them. Turbine 1 inlet temp dropping (83K) Power leads cooled and stablized, coil temps came down. Leaving it for 1/2 hour to evaluate.
Power leads have flatlined but still building LHe level.
Coils temps <10K.Switching to series mode.
Raised PIC229 to 11Bar. Started to close HIC155. Cooling rates improve.
Even though cr_c1 and cr_c12 have begun to tick down, cr_c7 and cr_c6 are actually ticking up. This is probably a wave of warming propagating through the solenoid. As long as the two inlets are falling in temperature then things are going in the right direction. Once the warm wave travels through the outlets will begin to cool as well.
cr_c1 and cr_12 are both at about 45K and heading slowly down, so the gamble of going to // cold return worked. Maximum opening of CV155 is limited by CV204 goes fully closed and suction pressure begins to rise above set point. Adjust cv155 to keep cv204 just at the closed point. Keep tweaking cv155 and turbine speeds as things get cooler.
TIC121 was down to 27K warm return valves were wide open opened supply valves CV143 and CV146. TIC121 went up to about 37K Mu1 return temperature went down to about same temp as TIC121 so set Mu1 to cold return. Open CV145 then close CV151. Mu2 return was still > TIC121 so kept it in warm return mode. Adjust turbines as required. After about 20 minutes Mu2 return temp dropped down to about equal to Mu1 return temp of about 38K. Then set Mu2 to cold return. Open CV147 then close CV143. TIC 121 drops to 30 K. Even though Mu1 and Mu2 return temps greater than TIC121 I will keep it in //cold return mode to see if the core solenoid temperatures will start to fall. To maximize the use of the cooling from T2 outlet temperature CV155 is tweaked open to its maximum stable opening. This helps cool the lower heat exchangers. If this works then cr_c1 and cr_c12 should start to tick downwards. If they keep rising then have to switch back to //warm return.
Mu2 pressure was just about at trip point due to trapped volume of helium warming. So opened up warm returns to bleed off pressure and prevent it from rising.
Started flow to turbines. Both started. T1 seems a bit slow. HIC110 at 0.85 SI110 = 4100. Cool down started.
I will leave the cold box to warm overnight and try it again in the morning.
T1 will not spin up. Warming up cold box.
Solenoid Quenched on C1 temp. It went above 5K. Shut off compressor. Restarting system @ 12:15
test
power lead warming/ripples caused quench at 18:45 today. Compressor stayed on, but flow to solenoid stopped. I started flow to solenoid at 22:40.
Tuesday night. June 27, 2006, the solenoid quenched for no apparent reason. It was restarted Wednesday morning. The vacuum in the solenoid went away (up to 8 Torr). This was found to be a result of a leaking isolation valve between the solenoid and T2. T2 was vented, which caused the solenoid to slowly vet. When T2 was pumped out again, the solenoid vacuum recovered. This caused a delay in recovering the solenoid. As of Friday morning 7:15 the solenoid power supply was ramped up.
I would have made an entry when it died, but-----
LI108 indicates high on EPICS screen (150%) Controller shows ~64%
Powerleads appear stable.
Had system in //return cooling overnight with small flow to keep power leads cool. Switched to series mode about 30 minutes ago. Building LHe level.