Short Term Run-Plan

The sections in italic refer to offline analysis by experts.

The Full Run Plan is available to you here for your information. The short-term run plan is outlined below. The tasks at hand on any given day should be at the top of this page. The page will be updated regularly. Tasks below the line have been completed but are kept on this page for reference.

Short Term Run Plan Saturday, September 16

1. Following items when convenient (not yet scheduled)
   1. Beam Energy measurement
   2. Moeller measurement: Monday?
   3. BCM Calibration
   4. 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.
2. Establish the HMS-NPS coincidence. For reference, you may consult Section 2.2 of the Full Run plan. This part of the Run plan is expert-driven (Alex, Chandan, Simona and others)
   1. Move the NPS calorimeter to 12.12 deg. That's 12.12+16.3=28.42 deg for the SHMS.
   2. Check that the HMS is set at -4.367 GeV/c with the large collimator.
   3. Ask MCC for the NPS Sweep Magnet and compensation commissioning for this angle.
   4. NPS pedestal measurement: take a CODA run with the beam off. NPS HV and LV on. The goal is to get pedestal measurements for the NPS DC Anode current monitor.
   5. Ask for 5 microAmp beam on LH2.
   6. Take a HMS 3/4 only trigger run (PS3=0, all others –1). Take a short run (5-10 minutes). Verify that DC anode current (after beam-off pedestal subtraction) is less than 30 muAmp.
   7. Take a longer run.
      1. Check parameter FADC250 SPARSIFICATION = 0 in file nps-vme1:nps-vme/cfg/coin/nps-vme.cfg, to readout all waveforms
      2. 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.
      3. Analyse NPS Waveform data to find time spectrum of pulses. Look for true coincidence peaks.
      4. Analyse NPS Waveform data to verify VTP found all clusters.
   8. If all OK, take a 1 hour run with FADC250 SPARSIFICATION = 1
3. Elastic Calibration of Calorimeter. Expected duration 13h. For reference, you may consult Section 2.3 of the Full run plan.
   1. Setup HMS : positive polarity p_HMS = +4.036. HMS angle =30.145 deg
   2. Set NPS calorimeter to 15.759 deg. That's SHMS at 15.759+16.3=32.05 deg.
   3. Use LH2 target
   4. NPS Sweep Magnet Off.
   5. CODA setup PS3=0, all others -1 (or possibly PS5=0, others -1 if the proton rate is so high as to create a lot of deadtime)
   6. NPS DAQ configuration:
      1. DTP cluster trigger threshold=500 MeV and readout threshold =100 MeV. The expert is Wassim Hamdi.
      2. check that VTP_NPS_FADCMASK_MODE = 1 (7x7 cluster readout)
   7. For each run condition below: check the anode current is less than 30 uA (using the GUI) and that the number of NPS clusters found per event is less than 15. The expert is Wassim Hamdi and he can check that for you. If necessary, lower the beam current and adjust the run duration. Also, check for saturation of FADC250 amplitude signals (no samples >4000).
   8. Take a one-hour run at 30 uA with the NPS at 15.759 deg (adjust beam current < 30 muAmp to keep NPS Anode DC current < 30muAmp).
   9. Take a one-hour run at 30 uA with the NPS at 14.673 deg. That's SHMS at 14.673+16.3=30.973 deg
   10. Take a one-hour run at 30 uA with the NPS at 16.965 deg. That's SHMS at 16.965+16.3=33.265 deg
   11. Now repeat for more statistics
   12. Take four one-hour runs at 30 uA with the NPS at 15.759 deg (adjust beam current < 30 muAmp to keep NPS Anode DC current < 30muAmp)
   13. Take four one-hour runs at 30 uA with the NPS at 14.673 deg. That's SHMS at 14.673+16.3=30.973 deg
   14. Take four one-hour runs at 30 uA with the NPS at 16.965 deg. That's SHMS at 16.965+16.3=33.265 deg
4. HMS Optics data Expected data taking time ~6h. For reference, you may consult the Full Run Plan Chapter 3.
   1. Optic calibration at 6.117 GeV/c. (we have a similar one to do at -5.442 GeV later)
      1. Set HMS at -6.117 GeV and 12.373 deg. Put the Sieve in position.
      2. Set the NPS to 15.96 deg (That's the SHMS at 15.96+16.3=32.26 deg
      3. DAQ prescales ps4=1 (HMS El-REAL), all others at 0.
      4. Set the FADC Threshold for NPS at high values (which ones?), turn on sparsification and TET_IGNORE to 0. The NPS HVs and LVs are off during these runs
         1. beam current 30 uA,
         2. NPS sweep magnet off, HMS Sieve in place, target C 0.5%, Run time 0.5 h. Expected HMS rate 2.2/sec/hole.
         3. NPS sweep magnet off, HMS Sieve in place, target Optics foils +/- 8cm, Run time 1 h. Expected HMS rate 0.9/sec/hole/foil.
         4. NPS sweep magnet on, HMS Sieve in place, target C 0.5%, Run time 0.5 h. Expected HMS rate 2.2/sec/hole.
         5. NPS sweep magnet on, HMS Sieve in place, target Optics foils +/- 8cm, Run time 1 h. Expected HMS rate 0.9/sec/hole/foil.
         6. NPS sweep magnet off, HMS Sieve in place, target Optics foils +/- 3cm, Run time 1 h. Expected HMS rate 0.9/sec/hole/foil.
         7. NPS sweep magnet off, HMS Large collimator, target LH2 Run time 0.5 h. Expected HMS rate 2 Hz (??).
         8. Move HMS to 19.26 deg
         9. NPS sweep magnet off, HMS Large collimator, target LH2 Run time 0.5 h. Expected HMS rate 2 Hz (??).
         10. Move HMS to 22.12 deg
         11. NPS sweep magnet off, HMS Large collimator, target LH2 Run time 0.5 h. Expected HMS rate 2 Hz (??).
5. Repeat Elastic calibration of the NPS with new HV set. Expected data taking duration 13h.
6. VTP trigger validation/efficiency studies
   1. 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
   2. Restore to 20 ns. Take a run with FADC250_NSA 36
   3. Analysis to check for stability of efficiency/deadtime
7. Rate/Deadtime vs threshold study in DVCS setting KinC_x36_5
   1. 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

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Short Term Run Plan Friday Sept 15, 2023

1. Do not move either spectrometer without consulting RC
   1. HMS at 16.44 deg (was iced up last week), SHMS iced up today.
   2. Expect to be able to move NPS Calorimeter from 12.2 to 20 degrees. Start at 20 degrees
   3. Note: NPS calorimeter angle = SHMS set angle minus 16.30 degrees
2. All data taking with coinc DAQ
   1. HMS `Single arm' data can be taken with PS3 and/or PS4 ≥ 0 (1:1) and PS5 and PS6 –1 (off).
   2. NPS randoms can also be taken with PS1 ≥ 0: This trigger includes the EDTM
   3. RunSheets
   4. For online analysis instruction refer to [1]
3. Initial standard equipment checkout.
   1. NPS Sweep Magnet and NPS HV off until start of coinc DAQ commissioning.
   2. Beam Centering on Carbon Hole hallcweb.jlab.org/wiki/index.php/Beam_Checkout_Procedures (Coordinate with Dave Gaskell).
   3. Take a short run with rastered beam through empty cylinder (tube) target. The goal is to see minimal change in the ion chamber readings when going through the tube.
   4. BPM Calibration vs. Harp Scan (Bull eyes scan) follow these instructions: [2]
   5. HMS detector verification. The relevant parts of the Run Plan (sections 2.1.6 & 2.1.7) are copied below. HMS nominal momentum -4.367 GeV/c. Start with 10 microAmp beam.
      1. Increase Q2 by +20% current compared to its nominal values to fully illuminate the focal plane. HOW_TO change the current in the HMS). 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 (how to). Start with a 5 min run, then a 1 hour run, keep data files below 3M events. Keep the 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 that the events rate after cuts is close to expectations ( Zheng Huang).
      2. Return HMS-Q2 to nominal setting. Run for 1 hour. Use LD2 target. Keep prescales same as for the defocussed setting and record equal sized files. Expect 840 DIS events/sec at 10 microAmp on LH2 target.
      3. Take a 10 minute run with all HMS FADC channels in mode10
   6. PID (electron id) checkout with HMS momentum lowered to 3.60 GeV to keep pions below Cherenkov threshold (4.02 GeV/c)
      1. 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.
      2. Run for 1 hour with PS3= –1 and PS4 = 0. Compare Cherenkov signals of the two runs.
   7. NPS Sweep Magnet and compensation commissioning (Calo=20deg) for first look at calo signals while taking HMS optics data
   8. Initial Optics run: take a one hour sieve slit run (HMS single arm), HMS EL-REAL prescale (PS4) =0 and HMS 3/4 prescale(PS3) value 5 (HOWTO prescale values). Single target foil. Ibeam=30 uA (scale run duration if you cannot get 30 uA). Look at xfp versus yfp: the goal is to get at least 200 events per hole. This is how to put the sieve in position.