Transversity Run Plan 1st Order
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Commissioning Part, updated 10/24/08 X. Jiang
1. Beam delivery checkout with one-pass beam, initial checks. Start up conditions: Beam energy lock: ON Hall A. Beam raster: OFF. Target: empty or BeO as needed. Beam entrance and exit window cover OUT. HRS_L at 16 degree, negative mode, quards cycled, P_HRS=-1.174 GeV/c Front sieve slit piece and mounting-plate:OUT. BigBite at 30 degree, 1.5 m drift (target to front surface of BigBite magnet), 710 A current, NEGATIVE polarity. Front sieve slit: OUT completely. 1.1 Beam tuned straight, not through Compton magnets. 1.2 !!!Dropped OUT, X. Jiang 10/22/08!!! Compton detector initial check. 1.3 Harp scan, require that beam sigma_x: 100~200 micron, sigma_y:100~200 micron on two hall A harps. 1.4 Check signals from lumi-monitors, beam position monitors, beam charge monitors. 1.5 Happex beam charge feedback check. !!! A separate commissioning plan and procedures here.!!! 1.6 Center beam on the BeO target's cross mark. Record BPM A and B readings in (x, y). 1.7 Verify settings of target Ion chamber trip limit (MCC with Radcon). 1.8 Beam goes straight to the viewer at the beam dump. 1.9 Does BigBite magnet stearing the beam ? Turn BigBite magnet ON/OFF, let MCC watch the beam dump screen, make logbook entry. 1.10 When Arun is back from DNP, and after make sure that Hall A beam charge monitors work, Perform a beam charge calibration, in two steps, need to coordinate with other halls: i, MCC calibrate injector beam charge monitor against Faradi cup at injector. ii, Hall A calibrate beam charge monitor against the injector BCM. Run beam in steps, up to 50 uA !!!, make sure it is RASTERED beam, 2mm by 2mm. Take CODA data at the same time. 2. One pass polarized beam, E0=1.234 GeV, HRS single arm runs for target alignment and detector shakedown. HRS_L@16 degree, negative polarity, quasi-elastic kinematics, P_HRS=-1.174 GeV/c, for C12 quasi-elastic kinematics. Front sieve slit plate:OUT. 2.1 HRS_L single arm DAQ check and detector shakedown. Target: carbon single foil. Beam current: < 5 uA, keep it low. Beam raster: ON, 2mm by 2mm DAQ: take HRS_L singles trigger. If BigBite is ready, can also take BigBite singles at the same time. check out beam position at target with spot++. check out detectors: VDCs, S1, A1, RICH, short gas Cherenkov, S2M and Leadglass blocks. check out beam related information in data stream for: BPMs, BCMs, beam RF timing, beam helicity. check out scalers. Target spin signal, even if polarized target is not ready. check target OTR if MCC confirms that it is working (need confirm with Arne Freyberger, ext-6268) Offline analysis: beam helicity scalers make sense ? Beam position decoding, spot++ parameters set right according to servey ? Spot++ beam location agrees with MCC's beam spot display ? Can we clearly see the target foil in y_tar, and in reconstructed z_tar ? Resolution better than 2cm in z_tar (FWHM) ? 2.2 Target alignment check using carbon hole target. And beam bullseye scan. Target: carbon hole target. Beam current: < 5 uA. Beam raster: ON DAQ: take HRS_L singles. BigBite magnet: ON, negative polarity, I=710 A. Change raster size, from 2mm*2mm to 4mm*4mm, take runs with HRS_L singles, use spot++ to tell if beam hits the carbon hole. The hole size is 1mm in diameter. The hole might be too small (?). Move beam around to center on the carbon hole (through a grid of BPMA and BPMB, in parrellel lines so that the beam angle is small). Establish this point as the nominal beam center position. Put spot++ plot in logbook. Then do a beam bullseye scan, take separated HRS_L single arm run for each beam position: this is for beam position calibration. i. One run at the nominal beam center as established already. ii. One run at (x,y) of both BPM A and B at (+3.0, +3.0). (if it takes more than 5-10 minutes for MCC to set it up, settle with (+2.5, +2.5) or lower values) iii. One run at (x,y) of both BPM A and B at (+3.0, -3.0). iv. One run at (x,y) of both BPM A and B at (-3.0, -3.0). v. One run at (x,y) of both BPM A and B at (-3.0, +3.0). 2.3 Target cell alignment check using polarized He3 cell. Target: polarized He3. Beam current: < 5 uA. Beam raster: ON DAQ: take HRS_L singles. BigBite magnet: ON, NEGATIVE polarity, I=710 A. Take runs with HRS_L, record BigBite singles rates, wire chamber rates. Change raster size until rates have a dramatic change, that's when the beam hitting the cell wall. If needed, move beam around with the same amount on BPMA and BPMB (through a grid in locations) Reduce raster size, to settle around 2mm*2mm. 2.4 If beam can not go through the dump straight, check beam steering by turning BigBite magnet ON/OFF. Coordinate with target expert on turning the target coorection coils ON/OFF. 2.5 Ask Eugene Chudakov to check if beam is acceptable for a Moller measurement. Ask MCC to record the beam tune setting, inlcuding the raster setting and the Moller quards settings. Make a Moller measurement when we are satisfied with beam delivery, after we have a working polarized He3 target (Eugene Chudakov). 2.6 A run with a large beam charge asymmetry, with HRS_L+BigBite coda, Moller taking runs at the same time. To verify the signs of beam helicity signal between different systems are consistent. (Eugene Chudakov and Bob Michaels). 2.7 Beam charge calibration (Arun Saha). !!! Turn BigBite wire chamber and pre-shower+shower HV OFF !!! Carbon single foil target, beam current 1 uA to 50 uA, raster ON. !!! Remember to take HRS_L singles runs while we're doing beam charge calibration. !!! Check Lumi data to see if counts scale with beam current. Offline analysis: update BCM convertion factors. Plot Lumi counts vs beam currents. Injector's BCM reading in EPICS data stream ? 3. One pass polarized beam, E0=1.234 GeV, HRS single arm runs with the polarized He3 target. If BigBite is ready, we can take some BigBite singles trigger at the same time. HRS_L at16 degree, negative mode, He3 \Delta-production kinematics, P_HRS=-0.850 GeV/c HRS_L front sieve slit and holding plate: OUT. If BigBite is ready, take BigBite single arm trigger at the same time. BigBite current 710 A, NEGATIVE polarity. BigBite sieve slit: OUT. 3.1 Carbon single foil run, 5 uA, raster ON/OFF, 5 min each. 3.2 Carbon multi-foil run, 5 uA, raster ON/OFF, 5 min each. 3.3 Pol. He3 target, transverse in-plane polarization, trans. asy. measurement. Raster: ON. Beam current: 10 uA (xxx ask JP again xxx) Total number of HRS_L trigger taken: xxx.xx !!! Arrange a beam half-wave plate IN/OUT change half way through these runs. !!! 3.4 !!! Tests of target spin flip while in step 3.3. !!! Offline analysis: do we see a clear double-spin asymmetry A_LT ? does it change sign when target spin flips. Beam half-wave plate IN/OUT. 3.5 Set to He3 elastic kinematics, cycle HRS_L quards, P_HRS=-1.213 GeV/c, HRS_L at 16 degree. HRS_L front sieve slit and holding plate: OUT. 3.5.1. Rotate target to Long., Pol. for He3 elastic Asymmetry calibration. Target spin flip: OFF, but target spin-signal ON. 3.5.2 He3 cell run. Raster:ON, Beam current: < 15 uA (?). Total number of HRS_L trigger taken: xxx.xx Arrange a change of beam half wave plate IN/OUT. Offline analysis: do we see a double spin asymmetry A_LL ? Does it change sign with beam half-wave plate IN/OUT ? Monte Carlo: what is the expect He3 elastic asymmetry ? 3.5.3 Reference cell run, He3 pressure curve. Run He3 gas pressure 20~150 psi. Purge reference cell first. Raster:ON. Beam current: 15 uA. 5 min each run. 5 steps total. Offline analysis: single-arm yields and scalers scale ? Lumi readings scale with He3 pressure ? 3.5.4 Reference cell N2 runs, gas pressure, 20~150 psi. Purge reference cell first. Raster:ON. Beam current: 15 uA. 5 min each run. 5 steps total. Offline analysis: single-arm yields and scalers scale ? Lumi readings scale with N2 pressure ? 3.6 At the end, set HRS_L back to C12 quasi-elastic kinematics, P_HRS=-1.174 GeV/c. Don't have to cycle the quards if we are coming down in momentum setting. 3.6.1 Carbon single foil run, raster ON/OFF, beam current 5 uA. 5 min. 3.6.2 Carbon multi-foil run, raster ON/OFF, beam current 5 uA. 5 min. 3.7 Take an access to insert HRS_L front sieve slit. 4. One pass polarized beam, E0=1.234 GeV, HRS_L single arm optics runs with Sieve Slit. Carbon elastic with sieve slit IN first, then OUT. HRS_L@16 degree, negative mode, quasi-elastic kinematics, P_HRS=xxx.xx GeV/c for C12 elastic kinematics, and P_HRS=-1.174 GeV/c for C12 quasi-elastic kinematics. Front sieve slit insert:IN. At C12 elastic kinematics: 4.1 Carbon single foil target run, raster ON/OFF, beam current 5 uA. 5 min each For pionting check and BPM/raster decoding check. 4.2 Carbon multi-foil target run, raster ON/OFF, beam current 5 uA. 10 min each. Offline analysis: while cutting on c12-elastic peak, do we see clear sieve slit patterens corresponding to each carbon foil ? 4.3 Change to C12 qausi-elastic kinematics Don't need to cycle the quards. 4.4 Carbon multi-foil target run, raster ON/OFF, beam current 5 uA. 10 min each. Offline analysis: do we still see a clear sieve pattern ? It's OK if we don't, since the sieve is not thick enough. 4.5 Carbon single foil target run, raster ON/OFF, beam current 5 uA. 5 min each. Offline analysis: centrual foil should show up at the same location. 4.6 Take an access to take out HRS_L front sieve slit AND the supporting plate. While we are taking the access, cycle HRS_L quards, set magnet back to C12 elastic kinematics. Again, at C12 elastic kinematics 4.7 Carbon single foil target run, raster ON/OFF, beam current 5 uA. 5 min each. Offline analysis: do we understand cross section. Does raster ON/OFF make any difference ? 4.8 Carbon multi-foil target run, raster ON/OFF, beam current 5 uA. 5 min each. Offline analysis: we should be able to understand cross sections from every foil. 4.9 Change HRS_L to C12 qausi-elastic kinematics. Don't need to cycle the quards. 4.10 Carbon multi-foil target run, raster ON/OFF, beam current 5 uA. 5 min each. Offline analysis: we should be able to understand the change of acceptance. Compare with HRS_L Monte Carlo for acceptance change. 4.11 After these activities, we are ready to move HRS_L to 58.1 degree when we have a chance. !!! Follow the Operation Safety Procedures !!! 5. BigBite single-arm runs, detector and DAQ checkout. One pass polarized beam, E0=1.234 GeV. At the same time of HRS single-arm runs, BigBite at 30 degree, 710A magnet current, NEGATIVE polarity. BigBite sieve slit: OUT. 5.1 Detector shakedowns, carbon single foil or multi-foil targets, 5 uA beam. Check wire-chambers, gas Cherenkov, preshower+shower, scintillators. 5.2 Wire-chamber HV scan, threshold voltage scan. 5.3 Check beam helicity sorted BigBite scalers, synk-check of HRS and BigBite scalers. 5.4 Check target spin gated BigBite scalers. 5.5 Check Lumi-monitors. "Seudo-Synk" check of Lumi and BigBite scalers. Offline analysis: does lumi infor line up in time with BigBite event ? 5.6 BigBite trigger threshold check. 5.7 Verify DAQ dead time calculaion from scalers. 5.8 Beam current vs wire chamber dark current scan. 5.9 Check start-of-run and end-of-run CODA log entry. 6. BigBite single arm runs, optics study. One pass beam, E0=1.24 GeV, polarized. BigBite at 30 degree, 710 A current NEGATIVE polarity. BigBite sieve slit: OUT, to start with. 6.1 Carbon single foil run, < 5 uA beam, raster: OFF/ON one run each, 5 min. 6.2 Carbon multi-foil run, < 5 uA beam raster: OFF/ON one run each, 5 min. 6.3 Chage target to reference cell, fill with H2 gas 150 psi. Raster: ON, 2mm by 2 mm, beam current: 5-10 uA. Take one run H(e,e'), 5 min. Or until we are satisfied that everything is working fine. 6.4 Take an access, drop in BigBigte sieve slit. Reference cell filled with H2 gas, 150 psi. Raster: ON. Beam current: 5-15 uA. Take a few runs of H(e,e'). The expected BigBite "elastic" H(e,e') rate is ~ 20 Hz per 1 uA beam current. Take a total of ~2.0 million BigBite triggers (or 1.5 hour maximum at 10 uA current). 6.5 Carbon single foil run, 5 uA beam, raster: OFF/ON one run each, 5 min. 6.6 Carbon multi-foil run, 5 uA beam raster: OFF/ON one run each, 5 min. Verify that we can see each carbon foil in z_tar. Is the sieve slit patteren visible ? (It's OK if the pattern is not clear). 6.7 While BigBite sieve slit is in, take one run with carbon multi-foil target and BigBite field off, raster off. Reduce beam current to < 0.5 uA if necessary. Take another run with carbon single foil target, raster:off, BigBite field off. These runs help to define detector offsets. Offline analysis: can we see tracks clearly ? Operation time limit: 1 hour maximum with beam on. If we can't get clear tracks, move on. 6.8 At the end of this activity, make sure the HRS_L sieve slit plate is out already. If necessary, make an access to remove the HRS_L sieve slit plate. 7. BigBite+HRS coincidence runs, and single arm runs, optics study. HRS_L at 58.2 degree in POSITIVE polarity, P_HRS=0.62 GeV/c. HRS_L sieve slit plate: OUT. Follow Operation Safety Processure while moving HRS_L to 58.2 degree, get tech on-call in the hall. BigBite at 30 degree, 710 A current. BigBite sieve slit: IN, to start with. Take all coincidence T5 trigger, take HRS_L and BigBite singles each at ~200 HZ. 7.1 Carbon single foil run, 15 uA beam, raster: OFF/ON one run each, 5 min. For coincidence vertex reconstruction, check pointing offsets. Offline anaysis: do we have a clear agreement between z_tar of HRS_L and that of BigBite ? Does the reconstructed z_interaction show up different for raster IN/OUT ? How much better can we correct z_int using beam infor from BPM+raster_current ? This will determine our final z_tar cut in the production data. 7.2 Carbon multi-foil run, 5 uA beam, raster: OFF/ON one run each, 5 min. Offline anaysis: do we have a clear agreement between z_tar ? 7.3 H(e,e'p) coincidence run, with reference cell H2 gas ~150 psi. raster ON 2mm by 2mm, beam current 15 uA. BigBite sieve slit: IN. Online replay: for T5 events, is the elastic proton peaks roughly at the middle of the HRS_L delta spectrum ? If not, slightly lower the HRS_L momentum to center the peak in delta. Check coincidence trigger. Coin. Time-of-flight, S2M t0 offsets. Beam RF timing signal check. Expected T5 rate is roughly: ~30 Hz on elastic peak for 15 uA beam. Take 100 k coincidence trigger. Estimated time: 1 hour. Offline anaysis: do we see the partial image of BigBite sieve slit in HRS_L \theta_tar vs \phi_tar ? 7.4 When we are satisfied with the coincidence time-of-flight spectrum, and the sieve slit image, make an access, take out the BigBite sieve slit. 7.5 H(e,e'p) coincidence run, with reference cell H2 gas ~150 psi. raster ON, beam current 1~5 uA. BigBite sieve slit:OUT. 7.6 Carbon multi-foil run, 5 uA beam raster: OFF/ON one run each, 5 min. 7.7 Carbon single foil run, 5 uA beam, raster: OFF/ON one run each, 5 min. 7.8 H(e,e'p) coincidence and H(e,e') single arm run. Reference cell H2 gas ~150 psi. raster ON, beam current 15 uA. BigBite sieve slit:OUT. Elastic rate for T5 is ~400 Hz, BigBite singles is ~25 kHz. !!! Dropped OUT, (X. Jiang 10/24/08) !!! Change BigBite magnet current, in 5 steps to ~20% of Max. (710A). i.e. at 710A, 596A, 483A, 369A, 256A, 142A to have elastic electron event spread over several rolls of lead-glass blocks. These runs are for preshower+shower PMT gain calibration. Take presacled BigBite singles, 1.0 million trigger each run (or 20 min each run). Shower+preshower hardware gain adjustement through PMT high voltage changes. Repeat runs at BigBite current 710 A, after HV adjustment. Offline analysis: sotfware gain calibration. Check trigger threshold settings. 7.9 H(e,e'p) coincidence run, with reference cell H2 gas ~150 psi. raster ON, beam current ~5 uA. BigBite sieve slit:OUT. BigBite magnet current: 710 A. Keep beam current the same in these steps. Set prescale factors so that DAQ dead time is less than 15%. 7.9.1 One run with T5 only, nothing else. take 200k T5 (or 0.5 hour). The expected T5 rate is ~25 Hz per 1 uA beam current. 7.9.2 One run with BigBite singles only, nothing else, take 1.0 million trigger (or 20 min). The expected BigBite singles elastic rate is ~2 kHz per uA beam. 7.9.3 One run take all T5, and 200 Hz of HRS and BigBite singles. take 200k T5 (or 0.5 hour). 7.9.4 Same setting as in 7.9.2, turn all HRS_L mangets off. One run. Take 1.0 million trigger (or 20 min). Do we see any change in shower ADC spectrum ? HRS_L magnets might have an impact on BigBite PMTs. Offlne analysis: do dead time corrections lead to consistant yields in these runs ? Hopefully from this run, we can demonstrate consistency in dead-time corrections, measure elastic cross section of H(e,e'p) and H(e,e'). 7.10 At the end of these activities, change beaam pass to two-pass, make an access to drop in the BigBite sieve slit, make sure that HRS_L sieve slit plate is: OUT. 8. IF possible, take BigBite single-arm data at the same time of HRS single-arm data during polarized target runs, as in steps 3.xxx. Make sure overall dead-time does not exceed 15%. 9. Two pass beam, BigBite+HRS coincidence runs, optics study. E0=2.400 GeV, beam polarization is not an issue. Beam tuned through Compton magnet. Moller quards off (? ask Eugene Chudakov). HARP scan to verify beam intrinsic spot size. We don't need the polarized He3 target in two-pass calibration runs. HRS_L at 46.4 degree in positive mode, P_HRS=1.235 GeV/c, HRS_L front sieve slit:OUT. BigBite at 30 degree, NEGATIVE polarity, magnet current 710 A. Front sieve slit:IN. !!! Remember to drop in BigBite sieve slit during the pass change. !!! Take all coincidence T5 trigger, take HRS_L and BigBite singles each at ~200 HZ. 9.0 Beam delivery procedure for two-pass beam. Tuning through Compton magnets. Moller quards: OFF (confirm with MCC+Eugene). Carbon hole target run to establish norminal beam+target center. Raster size change on reference cell to determine the best raster size. 9.1 Carbon single foil run, 5 uA beam, raster: OFF/ON one run each, 5 min. For coincidence vertex reconstruction, check pointing offsets. 9.2 Carbon multi-foil run, 5 uA beam, raster: OFF/ON one run each, 5 min. 9.3 H(e,e'p) coincidence run, with reference cell H2 gas 150 psi. raster ON, beam current 15 uA. BigBite sieve slit: IN. Online replay: for T5 events, is the elastic proton peaks roughly at the center of the HRS_L delta spectrum ? If not, slightly lower the HRS_L momentum to center the peak in delta. Check coincidence trigger. Coin. Time-of-flight, S2M t0 offsets. Beam RF timing signal check. Expected T5 rate is roughly:3 Hz. While BigBite sieve slit is in, take one run with carbon multi-foil target, BigBite field off. Reduce beam current to < 0.5 uA if necessary. 0.5 million triggers (or 20 min). Offline analysis: can we see the BigBite sieve slit's central hole clearly ? Take another run with single carbon foil target, I < 0.5 uA, BigBite field off. 0.5 millon triggers (or 20 min). 9.4 When we are satisfied with the coincidence time-of-flight spectrum, make an access, take out BigBite sieve slit. 9.5 H(e,e'p) coincidence run, with reference cell H2 gas ~150 psi. raster ON, beam current 15 uA. BigBite sieve slit:OUT. T5 rate: ~30 Hz, BigBite singles rate: 1 kHz. 9.6 Carbon multi-foil run, 5 uA beam raster: OFF/ON one run each, 5 min. 9.7 Carbon single foil run, 5 uA beam, raster: OFF/ON one run each, 5 min. 9.8 H(e,e'p) coincidence and H(e,e') single arm run. Reference cell H2 gas ~150 psi. raster ON, beam current 15 uA. BigBite sieve slit:OUT. !!! Dropped OUT, X. Jiang 10/24/2008 !!! Change BigBite magnet current, in 6 steps, i.e. at 710A, 596A, 483A, 369A, 256A, 142A to have elastic electron event spread over several rolls of lead-glass blocks. These runs are for preshower+shower PMT gain calibration. Take presacled BigBite singles, 1.0 million trigger each run (or 20 min each run). Shower+preshower hardware gain adjustement again. Sotfware gain calibration. Check trigger thrshold. 9.9 H(e,e'p) coincidence run, with reference cell H2 gas ~150 psi. raster ON, beam current 1~5 uA. BigBite sieve slit:OUT. Keep beam current the same in these steps. 9.9.1 One run with T5 only, nothing else. 9.9.2 One run with BigBite singles only, nothing else. 9.9.3 One run take all T5, and 200 Hz of HRS and BigBite singles. 10. E0=5.900 GeV, polarized beam, pre-production check out (1 day). Beam energy lock: ON, lock on Hall A. HRS_L at 16 degree, NEGATIVE polarity. P_HRS=-2.4 GeV/c. Front sieve slit:OUT. BigBite at 30 degree, NEGATIVE polarity, I=710 A. Front sieve slit:OUT. 10.1 Beam tune through Compton magnets, Compton detector commisioning. 10.2 ARC beam energy measurement (Arun Saha). 10.3 HARP scan in the Hall, verify beam intrinsic spot size. 10.4 Moller run. And a run with a large beam charge asymmetry, with HRS coda, Moller taking runs at the same time. To verify the sign of beam helicity signal between different system. (Eugene Chudakov and Bob Michaels, should repeat several times throughout the experiment). 10.5 Beam position vs BigBite background rate check. Using polarized He3 cell, to establish the nominal operating beam position. Start from the nominal beam position establised during one- and two-pass beam delivery. 10.6 Coincidence trigger check. Carbon multi-foil target, Beam raster:ON. Beam current: 1~5 uA. Offline analysis: check coincidence time-of-flight corrections. do we see (e,e'p) coincidence ? protons reach HRS focal plane 8 ns later than pions. With enough confidence, shrink TOF window from 100 ns to ~60 ns(?). Keep protons in the TOF window. The goal of on-line corrections is to have the corrected TOF resolution to 2 ns (sigma). 10.7 Pol. He3 target, transvers in plane polarization, spin-flip check. Offline analysis: All scalers make sense ? Lumi reading can be clearly lined up with real triggers in time ? FAst clock serev as time marks. The DAQ goal is to take at least 1 kHz (100 Hz coin.+900Hz singles) with 85% live time. 10.8 Are we done with the commisioning ? 10.8.1 BigBite detectors are all working, first order optics roughly working, clearly see carbon foils and sieve slit patten. 10.8.2 HRS_L detectors are all working. 10.8.3 Coincidence trigger works. All scalers make sense. 10.8.4 Target is polarized, spin-flip is working fine. Move on to production runs.