Log entry time 14:00:11 on May 15, 2004

Entry number 85195

• After the failed attempt to rotate the spin direction for Hall C, beam was deliver pretty steadily to the halls. The QWeak-SOS tests lasted from 6 pm to midnight, the group reported lots of electrons and left satisfied with their data. During the Qweak-SOS tests there were concerns about the raise of G0 tungsten radiator temperature. This raise was 5 times larger than during the first Qweak-SOS test. It was believed that the potentially large radiation created in the hall had prompted the SMS failure following the first Qweak-SOS test. This time around the SMS and its control components "behaved". It took an hour to resume G0 data taking once the Qweak-SOS investigators ended their work (to our relief).

• This morning, Hall B reported two events during which their slits were closed and the current they (still) received in the hall tripped the wire-chambers. As an example, the Hall B RC showed and plot of their halo target readings. Once during the night shift, the halo in the G0 girder was reported to be large ( entry # 85173 ). In order to solve this issue the beam delivery was stopped for ~ 3 hours this morning (it did escalated into various trouble shooting). MCC actually found some scrapping in the line before the BSY. I'll follow up on the issue. MCC people are too busy to write their report right now as they are experiencing trouble with the G0 laser (no beam since 1h : did you say lousy shift ?)

• The regular data taking routine is [1h,hall A, B and C on. half gain setting for the fpds, HV.2004-02-19.lumi_halo_on.hvc for the lumi] interleaved with 10 ' runs with Hall C laser off [hall A and B ON and Hall C off (hall C slit fully open), half gain setting for the fpds, HV.lumi_highhigh_on.hvc for the lumi. ]. Please take this kind of data but for the few tests explained below.
• Saturday, 2 hours of data taking (1 h regular run + 10 ' hall C off) at IA= 1 V and IA=9 V. Don't forget to turn off the feedbacks. The purpose of this measurement is to check the correlation between the hall C leakage on him-self with the charge asymmetry.
• Moller data taking today Saturday at 15:00, followed by a change of HWP.
• Sunday, the hall A will be turned off to accommodate our leakage studies from 6 am to noon. The same studies than the two previous time (see friday day shift summary ) will be conducted. In addition at 9 am, a short energy modulation will be performed (The idea here is to use the south linac energy lock cavities to vary the beam energy by +/- 1 MeV in steps of 0.5 MeV).
• Sunday from noon to four Hall A will go from 5 passes to 2 passes. This is invasive and should take 4 hours or so.
• Regular data taking up to Monday 7 am.

• The target and magnets will not be cooled down on Monday morning as the cryo-group is doing some tests (computer related) and are afraid of interferences.
• A survey of the ferris-wheel, the magnet and the g0 girder will take place on Monday (though I did not get any confirmation...)
• An extended GMS run will take place on Monday morning