Run Coordnator Report 2012/04/ /04/10 Jixie Zhang

Status Update Check HALOG, search for‘status’

Progress in Last Week Tue: during restricted acess 1)Target anneal, TE 2)Reset right dipole 3)Right T2 checked by Melissa and Ryan, but not solved, 4)Pnegjia and Chao solved left BCM problem (bad NIM to NBC converter) 5)Pengjia and Chao connected slow rasters to the 3 rd arm 6)Jack tested septum current at 850A 7)Fix the dump dehumidfier 8)Anthony checked the harps, problem not solved 9)Ed and Jack diagnosed the gears of the right sieve Wed: 1)Taking opics data 2)Continue taking production data. Beam energy drift all the time since hall C is not running, beam positions drift togather as beam energy. 3)Instrument group did harp scan twics. Swapped amplifier for both harps, but did not see difference. They consulted experts offline. 4) BTA issue: network, proxy reset

Progress in Last Week Thu: 1)Production 2)Harps was tested and finally find out that reduce the wire velocity works: A) it reduces the vibration which helps in reducing noice and B) it increases the signal since the wire stays longer in the beam 3)Target anneal started at 3 PM Fri: 1)Tried to do moller measurement. Finally cancelled due to the target magnet quench. 2)Target magnet quench. Nothing damaged. 3)Return to production by 3 PM. 4)Found that left HRS pion rejector HV was turned off by accident. Recovered and continue taking production data. 5)Found right BCM single missing from Tuesday. Plan to fixed it in Monday.

Progress in Last Week Sat: 1)Production 2)At 4 AM, the fuse of one of the FZ magnet VESDA lights broken 3)Target anneal started at 3 PM Sun: 1)Very high efficient production data taking. 2)Finish all kinematic points for g2p at GeV and 2.5T target field. Took 120M extra data at Delta resonence (P=1.940, W=1.232).

Progress in This Week Mon & Tue : 1.MCC changed linac energy to 415 MeV, Hall A got GeV. 2.Continue checking T2 3.3 rd arm position adjusted. 4.Chicane moved. 5.Vince work on raw data files overritten issue. Can not fix the bug, but can walk around it by killing the coda if it trys to overwritten an exist file. 6.Found right septum power supply keep triped at 6 PM. Jack looked into it. Smells like ground fault deterctor issue. Need accelarator experts to look at it. (Update: could be overheating in the magnet itself..., will test it after lunch) 7.MCC have injector issue, no beam until 7:20 AM 8.Hall A injector has large fluctuation in current. MCC is working on that 9.Pengjia did slow raster calibration and calorimater calibration. Harp scan and BPM is not able to do due high current is not available 10.Moller group are stand by

Third arm is designed to measure the asymmetry of elastic recoil proton Our final goal is to get a relative measurement of the target polarization from the asymmetry Third arm do not have dipole, so there is no momentum resolution, the sampling region is decided by the trigger threshold Simulation predict a ~600ppm raw asymmetry for GeV beam and 2.5T target field setting The preliminary result calculated using 2 days of data is shown on the left. The error bar is still large, we will combine more statistics. Four values are grouped by different IHWP state(IN/OUT) and different sign of target polarization(+/-) The sampling region of 3rd arm Third Arm Performance Slides by: Chao Gu (Univ. Virginia) 500ppm -500ppm IN,+ IN, - OUT, + OUT, -

3rd arm can also be used as a beam position monitor 2 Benefits to use 3rd arm: – Beam pipe is in the acceptance of 3rd arm, so 3rd arm will show some hot spots when beam hits the either beam pipe or frame – When centering the beam, 3rd arm can see the reference hole more clearly because of the large difference of the cross section between Al and He Scattering Chamber Scattering Chamber Beam Pipe 3rd arm can see hot spots when beam hits the pipe Left Arm 3rd Arm These 2 runs are taken simultaneously, only 3rd arm can see the hot spots from either beam pipe or target frame When we try to center the beam, 3rd arm can see a very clear reference hole in the pattern: Slides by: Chao Gu (Univ. Virginia)

Things to Do in the following week Optics for g2p GeV when beam recovered Fix the right septum magnet or power supply Wednesday beam study will be only 3 hours, the other part will be done next week. Might do target anneal, but not change material. Moller measurement was scheduled to Thursday, might be moved to Wednesday since beam study time shorted Hall B want to change pass in Friday (4 hours), Hall C want to change pass in Monday then go to high current Injector group want to change spot in Monday Another moller after spot changed. Change chicane at Apr 17(Tuesday) for gep Optics for gep Try to push hall B and C to change passes in Tuesday