Swing Shift Summary April 2nd 2012

SL: Ole Hansen (SL)
TO: Mikhail Yurov (TO)
3rd: Johan Sjoegren (3rd)

16:00 Start shift with Restricted Access in progress to investigate fire alarm from failed dump dry air compressor
18:25 Access ended. Sweep done. Hall in Power Permit.
19:00 DAQ problems. Rebooting various ROCs. This proved a bit trickier than normal because some boot parameters have to be entered by hand - apparently this is normal for these ROCs ...
19:24 Beam ready. Start target centering check with carbon hole target.
19:55 Beam reasonably centered on target. Starting brief harp scan.
20:10 Harp apparently not working. Suspect broken preamp. Decide to go back to production at p = 1.078 GeV. Moving target into position and starting to polarize target.
20:38 Starting production with bottom NH3 cell. Polarization is around 35%. Ibeam = 50 nA. IHWP = OUT.
21:45 Reached desired statistics at p = 1.078 GeV.
21.46 Hall C change IHWP to IN.
21:48 Starting to change momentum to 1.0028. Discover that RHRS dipole controls no longer responsive. R-dipole current stuck at 370.35 A, the value for p = 1.078.
21:49 Request MCC to do bleed-through check while we change momenta.
22:10 Discover that the "Optics Mode" in the regulator control pages was set to "No septum", but should have been "g2p/GEp_1". This means that at least all data taken so far in this shift are probably junk. Fortunately, there have been only about 75 minutes of production so far, so no major loss. The node probably got reset when various IOCs crashed during the fire alarm in the previous shift. We still have to verify that the problem did indeed not start earlier than this shift.
22:21 MCC calls to announce that the bleed-through from Hall C is smaller than they can measure, i.e. effectively zero.
22:33 We decide to re-take the p = 1.078 data with the right arm only (which is stuck at this momentum due to the loss of dipole control), and to continue with the next setting, p = 1.0028 GeV using the left arm only.
24:00 End shift with production at p = 1.078 (RHRS) and p = 1.0028 (LRHS) in progress.

Comments:

Dilution runs for p = 1.0028 GeV still to be done