Short Term Run-Plan
From HallCWiki
Short Term Run Plan Friday Sept 15, 2023 Full Run Plan
- Do not move either spectrometer without consulting RC
- HMS at 16.44 deg (was iced up last week), SHMS iced up today.
- Expect to be able to move NPS Calorimeter from 12.2 to 20 degrees. Start at 20 degrees
- Note: NPS calorimeter angle = SHMS set angle minus 16.30 degrees
- All data taking with coinc DAQ
- HMS `Single arm' data can be taken with PS3 and/or PS4 ≥ 0 (1:1) and PS5 and PS6 –1 (off).
- NPS randoms can also be taken with PS1 ≥ 0: This trigger includes the EDTM
- RunSheets
- Run Plan Chapter 2, as practical with HMS and NPS constraints
- NPS Sweep Magnet and NPS HV off until start of coinc DAQ commissioning.
- BPM Calibration vs. Harp Scan, Beam Centering on Carbon Hole hallcweb.jlab.org/wiki/index.php/Beam_Checkout_Procedures (Coordinate with Dave Gaskell).
- Fix Beam Angle at Target Use the gui target_bpm at /home/cdaq/users/gaskelld/target_bpm/target_bpm.py
- Adjust 3H07Ax, y to remove slope while keeping 3H07Cx, y fixed. Recheck carbon hole and iterate as necessary
- Take a short run with rastered beam through empty cylinder (tube) target.
- NPS Sweep Magnet and compensation commissioning by Jay Benesh and Bogdan Wojtsekhowski, when available and subject to NPS Motion constraints
- HMS detector verification: Run Plan sections 2.1.6 & 2.1.7, HMS momentum -4.367 GeV/c. Start with 10 microAmp beam.
- Defocus Q2 by +20% to fully illuminate focal plane. Use LD2 target. Set HMS 3/4 prescale to keep event rate below 1000/sec (expect 2 : 1 prescale). All other prescales −1. EDTM rate 100 Hz. Start with a 5 min run, then a 1 hour run, keep data files below 3M events. Keep event rate low enough for near 100% efficiency. Analysis lead: Mark Mathison. Verify that all Hodoscope bars are counting and focal plane is illuminated. Check that timing spectra make sense. Contact expert(s) if in doubt. Verify event rate after cuts are close to expectations ( Zheng Huang).
- Return HMS-Q2 to nominal setting. Run for 1 hour. Keep prescales same as defocussed setting and record equal sized files. Expect 840 DIS events/sec at 10 microAmp on LH2 target.
- Take a 10 minute run with all HMS FADC channels in mode10
- PID (electron id) checkout with HMS momentum lowered to 3.60 GeV to keep pions below Cherenkov threshold (4.02 GeV/c)
- Run for 1 hour with PS3 ≥ 0 and PS4=–1. Check for clean Cherenkov distribution with selection of high energy signal in Shower. Check for clear single photo-electron peak with selection of MIP (pion) signal in Shower counter.
- Run for 1 hour with PSS= –1 and PS4 = 0. Compare Cherenkov signals of the two runs.
- Following items when convenient
- Beam Energy measurement, defer until after elastic calo calibration runs
- Moeller measurement: Monday?
- BCM Calibration
- IA scan for feedback. This needs to wait until after we have been able to (roughly) calibrate the Hall C BCM in the parity DAQ (should be able to use the ion chamber calibration data for this). This should be coordinated with NPS and Moller polarimeter data runs to compare the asymmetry sign in the three systems. Estimated time is about 1 hour of beam.
Weekend?
- Verify HMS and coinc DAQ with HMS at -4.367 GeV/c, NPS Calo at 12.12 deg. Run Plan Section 2.2
- NPS Sweep Magnet and compensation commissioning must be completed (at least for this angle setting)
- Pedestal measurement Pedestal How To
- Also Beam-off pedestal measurement via epics only (A. Camsonne) for Anode DC current calibration
- Start with 5 microAmp beam. Take a random coincidence run: PS3=0, all others –1. Take a short run, then a longer (one hour) run.
- Verify that DC anode current (after beam-off pedestal subtraction) is less than 30 muAmp. 1 FADC250 count is 19.5 fC. 30 muAmp is a count rate of 1.5e9/sec (in a single crystal).
- Check parameter FADC250 SPARSIFICATION = 0 in file nps-vme1:nps-vme/cfg/coin/nps-vme.cfg, to readout all waveforms
- Look on scope with persistence mode for true coincidence peak between HMS (PS3) and NPS (PS1) signals. Delayed HMS 3/4 signal marked H3/4 in top chan of PS752 logic unit (4th from right) in main NIM bin in rack CH03B06. This is currently (15 Sept) plugged into scope HCSCOPE01 chan 2. NPS (Trig-1) is 2nd chan PS752, plugged into scope chan 1.
- Analyse NPS Waveform data to find time spectrum of pulses. Look for true coincidence peak.
- Analyse NPS Waveform data to verify VTP found all clusters.
- If all OK, take a 1 hour run with FADC250 SPARSIFICATION = 1
- Elastic Calibration of Calorimeter. Run Plan Section 2.3 (Chapter 2).
- HMS at Positive Polarity p_HMS = +4.036
- Three NPS Calorimeter settings: 14.673, 15.759, 16.965 deg
- PS3=0, all others -1 (or possibly PS5=0, others -1)
- NPS Sweep Magnet Off.
- Start at small angle 14.673, adjust beam current < 30 muAmp to keep Anode DC current < 30muAmp
- check that VTP_NPS_FADCMASK_MODE = 1 (7x7 cluster readout)
- check for saturation of FADC250 signals (no samples >4000)
- Interleave the three NPS/SHMS angle settings to get early preview of all data.
- During analysis of Elastic calibration data, take HMS Optics data (Run Plan Chapter 3).
- Once new Calo calibrated HV values are established, take a new suite of Elastic data.
- VTP trigger validation/efficiency studies
- take a run (elastic or DVCS kinematics) with coincidence time parameters increased from 20 to 40 ns: VTP_NPS_ECALCLUSTER_HIT_DT, VTP_NPS_TRIG_WIDTH, VTP_NPS_ECALCLUSTER_CLUSTER_PAIR_WIDTH
- Restore to 20 ns. Take a run with FADC250_NSA 36
- Analysis to check for stability of efficiency/deadtime
- Rate/Deadtime vs threshold study in DVCS setting KinC_x36_5
- Make factor of 1.4 variations (in tandem?) in thresholds FADC250_TET, VTP_NPS_ECALCLUSTER_SEED_THR, VTP_NPS_ECALCLUSTER_TRIGGER_THR, VTP_NPS_ECALCLUSTER_CLUSTER_PAIR_THR, VTP_NPS_ECALCLUSTER_CLUSTER_READOUT_THR