H-Jet polarimeter status report Yousef Makdisi RSC 07/28/06

Jet operations in `06 Igor and Dima provided the new code to readout the full waveform and monitoring program. Ron provided the daily PC technical support and monitoring. Anatoli and Yousef, the daily jet oversight and maintenance (a long haul but only 3 midnight calls) T. Wise came to the rescue of the SFT unit. MCR Operations took full responsibility and saw to it that data were collected in each fill.

Waveforms (new H-Jet data format this year) Fit Half maximum Baseline = 8

Overall Picture and Cuts

Snap shot of online Monitoring

Strips after the loss of detector 3

Energy Distributions

Click on Info

Data 100 GeV FillsDatesBeamEvents /18-25B2.5M /26-4/4Y2.8M /4-11B1.6M 4/11 Lost Si detector # /12-5/2Y3.8M /3-15B4.2M /19-6/1Y2.5M 6/2 Si detector acted up: reduced the bias from 200 – 175 V /3-5B2.0M

Data Collected at 31.2 GeV FillsDatesBeamEvents /9-17B3.6M /18-20Y2.6M

Data Analysis The `05 data is being analyzed by Oleg. Hiromi will complete the 24 GeV analysis for data taken in `04. This represents the first look at injection albeit with low statistics. The 31.2 GeV data provides a good statistical sample taken in conjunction with the polarimeters. It is closest to calibration at injection. (No one??) The 100 GeV `06 is waiting for a good volunteer. The change in the DAQ to readout the full WFD waveform (Dima) does not allow the use of the old analysis programs. Igor wrote the online analysis and monitoring program which could be used as a first step.

Raw asymmetries

Beam polarization

Comparison with pC-polarimeters

Operational issues Nozzle blockage frequency: every days. It takes 3 hours to warm up, ½ hour beam down, and two hours to cool down and back online. Slower intensity ramp up than before. 3-4 days to reach full intensity, plateau for a few days and then a slow decrease to blockage. Midway replaced the nozzle which improved matters somewhat. The SFT phase became unstable for a period. Fixed by T. Wise by increasing the gain. Lost some precious time due to memory full condition. Lost one silicon detector, and another acted up.

Operations continued Failed to take data with two beams at the same time: a)Requirement that the two beams be separated by 4-6 mm. b)The vertical collimation occluded the silicon acceptance. Determined no polarization loss with 112 bunch operation and p/bunch implying the holding field uniformity is adequate. Installed a CCD camera to look at light emitted as the beam hits the jet. This serves as another vertical beam emittance device. Our interest is to measure the molecular hydrogen contamination. No pump failure this run.

What is next? Determine the cause of the silicon failure. Replace the failed detectors with existing spares. Start discussion with Hamamatsu to purchase new detectors. Purchase spare WFD components. Will attempt to open up the vertical collimation to allow simultaneous two-beam measurement. Wisconsin is building two RF cavities to allow a polarized deuteron jet beam. Attempt to improve the jet vacuum to keep it on the beam line during Au-Au running.