16:00 Status at start of shift:
Moller experts (Sasha et al.) in the middle of Moller polarimeter
commissioning.
18:20 As requested by the RC, I have turned on HRSR and HRSL magnets; it required a number of tries to turn the current on to Right Q2, but eventually (a number of "Reset,OFF,ON" sequences from the GUI), and it finally responded to a request for a non-zero current. I cycle both Q2s using the 1000A, 0A, 1000A, to setpoint sequence, and Q3s by going to 1400 A and then down to setpoints.
We will be initially using "Tune Y":
Q1=547.483 A/GeV/c
Q2=446.039 A/GeV/c
Q3=532.516 A/GeV/c
which means at P0 =1.063 we have:
Q2= 582.081 A
Q2=474.139 A
Q3=532.516 A
Dipole regulation on; regulation for
the Quads is off, and the currents are just set by hand (since this tune
is not loaded into the P0 setting program yet).
18:40 Sasha makes controlled access to refill dewar for Moller Solenoid; Alex goes in for GEM-related work as well.
19:35 Sasha leaves hall; cannot completely fill the Moller dewar; is 25 units full only. The big dewar that he was filling it from is low. This is enough for 2-3 hours more, so we go-back to data-taking and meanwhile page Tech on-call (Howard) to see about adding He to big dewar.
19:39 Howard responds to page, consults with Sasha. Howard will call an expert.
19:48 Howard calls back, and explains to Sasha that the larger dewar needs to be more than 30% full before it can be used to fill the solenoid dewar; the larger dewar does fill automagically, but slowly.
So, we can continue with Moller data-taking, and then make another access once the larger dewar is more than 30% full and continue refilling solenoid magnet then.
20:50 We ask for another access, to again add He to the Moller solenoid.
21:10 Sasha is back out - helium level now 70% full. Ask for beam again for Moller
21:50 Sasha tells me that they have just seen that by reducing the field in the solenoid below the expected lebvel to saturate the magnetization in the foil, the measured beam polarization goes down, as one would expect - a good sanity check that the polarization that they are measuring is real. That is good news.
22:17 Moller measurement done. Sasha calls to move Moller target to parked position, and to restore previous beamline settings.
We will now move to counting-mode data with tune "Y". Ask for 0.5 µA to start, no target yet.
22:24 VDCs turned on, set to 4.0 kV
22:45 MCC has set up 0.5 µA. Ask for controlled access to set DAQ to counting mode.
Amplifiers of cavity monitors are off. 23:30 Zafar and I are back out; Zafar has changed upper and lower quartz and AT hole quartz in both arms from integrating(Parity DAQ) mode to counting mode(HRS DAQ).
23:40 Target Control computer has essentially frozen. Mark tries restarting the XServer. No joy. Do a hard reboot on the Target Control Computer. Get GUI back. Note that manuals and instructions appear out of date, since the Target Control computer is "POLTARAC" and it seems that the $cd GUI does not get to the correct directory; we fidn that the tgtgui command is in the subdirectory Screens, which we cd into and invoke .tgtgui. That works.
00:03 Move to "Thin Carbon" target, and ask for 0.5 µA of beam.
00:05 Shift ends....Hand off to next crew.