RHIC Polarimetry Status Basically ready for beam RSC
RHIC Polarimetry Status Basically ready for beam RSC 02/10/06 Alessandro Bravar et al.
What has been done / what is ready § installed all the Si detectors (6 + 6) and targets (6 + 4) no vacuum problems ! § Si detectors characterized (HV, gains, etc. ) § front end and shaping electronics installed, debugged, ready most (> 80%) modifications implemented, new shaper boards § DAQ extensively tested with Am source and pulser using internal and external clocks § controls via PAT and communication with CDEV working some details need still to be fixed (minimal impact on operations) tested data runs and target scan runs § Online software tested and working (“scaler” and “event” mode) § Target controls: Blue: OK; Yellow: ? ? ? requested / actual position: 1000 / 992 – 994 counts; 8 ct = 1 mm !!! RSC 01/13/06 POLARIMETRY
Some encountered problems § V 124 relocation of timing signals § Target controls hanging up § Fill pattern loaded with 0 § It happens, however this slows us down significantly RSC 01/13/06 POLARIMETRY
Waiting for beam §The polarimeter is basically ready for beam §Locate the targets §Adjust the timing gates (now fully open) §Create the configuration files – (energy correction and t 0) §Fine adjustment of the timing §Fully debug / solve unexpected problems RSC 01/13/06 POLARIMETRY
Still to be done: major compared to 2005 § More information sent to CDEV on the measurement – online Q&A – some online monitoring plots § Implement the target motion in the DAQ – – emittance measurements more reliable polarization profile measurements, etc. § Reanalyze the data in “real” time and broadcast the reanalized data / values to CDEV § Separate DAQ PCs for the Blue, Yellow and Jet § Debug remaining (very few) problems § Expect to be ready by the end of next week (as agreed !) RSC 01/13/06 POLARIMETRY
2006 polarization data § ONLINE -> CDEV: based on “scaler” mode (as during previous years) § Reanalyze each measurement in event mode in “real” time: – Q&A – Calibrations – Systematic studies For this need two persons taking polarimetry “shifts” Send the new values to CDEV and log (everybody will have access to these new values as soon as they become available) AIM: “preliminary” polarization soon after the end of the run § Target scans – relay on target hardware rather than software target “controls” – currently being developed § Want more? Time to ask now ! Will try to make everybody happy RSC 01/13/06 POLARIMETRY
Normalization § Based on actual measurements !! § Injection (24 Ge. V): Based on E 950 measurement in AGS at 21. 7 Ge. V/c D AN ~ 30 % Based on JET calibration in RHIC at 100 Ge. V/c D AN ~ 15 % RSC 01/13/06 FLATTOP § Flattop (100 Ge. V): POLARIMETRY INJECTION
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