Privacy and Security Notice

HNSS Beam Commissioning Plan

HNSS Beam Commissioning Plan

I Beam Energy: 1.953 GeV (Before 2/28/2000)  
  HNSS Settings: Splitter = 1.593514 T / 454.604 A, Split-Pole = 1.599816 T / 398.75 A  
  SOS D Settings = 1.31398 GeV/c, SOS Q Settings = 1.31398 x 0.915 = 1.202 GeV/c  
I.1 Target: Empty. Beam Commissioning Test Plan I MCC / Tang
  Fast E lock on Hall A. Splitter and Split-Pole off. SSD off. Gan / Gueye
  a. Ensure that the BCM electronics have been changed by AES group to  
  allow sensitivity in the low current range.  
  b. Set up Pulsed Beam (1.003 GeV) to the Dump. Beam straight through.  
  c. Set up 1 microAmp CW beam to the Dump.  
  d. Set the Maximum Current Limit to 2.5 microAmps for FSD system.  
I.2 Target: Empty / BeO. Beam Commissioning Test Plan II MCC / Gan
  Splitter and Split-Pole off / on. SSD off. Fast E lock on Hall A. Gueye / Sato
  a. BCM masked to allow pulsed beam tune.  
  b. Repeat I.1.b - c of Test Plan I.  
  c. Take Harp Swipe. Adjust the beam spot size at the target to <250 mm in  
  X and < 150 mm in Y (FWHM).  
  d. Log the OTR and BPM readings to note the Beam Energy Quality.  
  e. Turn Off beam and insert the BeO Target.  
  f. Turn Beam On in pulsed mode. Observe the beam on the target. Record  
  the beam on target position (by BPMs in front of target chamber and on  
  BeO target).  
  g. Turn off the beam. Turn on both the Splitter and Split-Pole Magnets to the  
  nominal setting for 1.003 GeV.  
  h. Turn Beam on in pulsed mode. The electron beam now will head towards  
  the Dumplette.  
  i. Observe the beam on BeO to check the Splitter fringe field effect on beam  
  position on target. Find offset needed for the position found in j.  
  j. Observe the beam on Viewer ITV3H00B downstream of the target  
  chamber and viewer or monitor in front of the Dumplette.  
  k. Using the BT magnets, steer the beam to the Dumplette.  
  l. Explore the range of the BT magnets with Splitter settings at extremes (as  
  dictated by the experiment's needs). If the BT's cannot center the beam on  
  the dumplette face, we may need to add more correctors.  
  m. Verify beam monitoring systems, displays, alarms, and EPICS quantities  
  for beam quality monitoring in data stream.  
  n. Check SOS trigger timings, 3/4, AC, LC, and GC. Prepare triggers. Sato/ Fujii
  o. Check Online replay. Sato
  p. Check HNSS hodoscope rate and displays. Fujii / Gan
I.3 Target: BeO. Beam Commissioning Test Plan III MCC / Mack
  Splitter and Split-Pole on. SSD off. Fast E lock on Hall A. Jinghua
  a. Notify the other halls. Current calibrations occur in the injector using  
  5 MeV Faraday cup.  
  b. Ensure that 30 Hz system or some other system that verifies clean aperture  
  to Hall C is working.  
  c. Turn Hall A and B lasers off.  
  d. Check machine aperatures with the 30 Hz system.  
  e. Record the voltages in the elog. Turn off the 30 Hz system.  
  f. Hall C slit wide open. Stable nominal 1 microA beam to Hall C.  
  g. (In the following, don't do anything that would knowingly change the  
  Hall C current.)  
  h. Steer beam to injector Faraday cup. Measure current. Record in the elog.  
  i. Restore beam to Hall C. Measure power emitted from bcm1, bcm2.  
  j. Steer beam to injector Faraday cup again. Measure current. Record in the  
  elog.  
  k. Back out (i.e., restore Halls A, B, and C. Hall C slits to nominal position.)  
  l. Continue to check SOS trigger timings and get KIP ready. Sato / Fujii
I.4 Target: BeO. Beam Commissioning Test Plan IV. MCC / Ent
  Splitter and Split-Pole on. SSD off. SOS sieve slit. SOS 3/4 trigger. Jinghua / Yuan
  Fast E lock on Hall A. Hall C fast position lock. Beam Current: 1mA. Murad
  a. Short SOS sieve slit run and check SOS optical center.  
  b. Adjusts beam position on target.  
  c. Adjust BT correctors to keep beam aiming to the Dumplette.  
  d. Repeat a to c to find finalized beam position on target.  
  c. Record in elog on the defined beam position on target.  
  d. MCC recheck the range of the BT magnets for the extreme.  
  e. Tune SOS Q to find the best FP tune.  
II SOS and HNSS Commissioning  
II.1 Part 1. SOS Trigger and HNSS Detector System Sato / Fujii
  Target: BeO. Posted 1.953 GeV HNSS setting. Jinghua
  Fast energy lock on Hall A. Hall C fast position lock on. No Raster.  
  a. Keep 1mA beam current and SOS large collimator.  
  b. Finalize the SOS trigger timing check: AC veto, LC coincidence, GC  
  veto. Lable the KID cables and complete the trigger diagram.  
  The trigger diagram must be in record.  
  c. Select SOS 3/4 trigger (e+).  
  d. Turn SSD on one at time. Check SSD performance. Threshold Scan. Lan
  e. Check and tune timing gate for SSD. Sato / Wood
  f. Check hodoscope signals and timing for TDC and ADC. Fujii / Sato
  g. Hodoscope gain matching. Runs with SOS 3/4 trigger. Fujii / Sato
  h. Take runs with SOS 3/4 trigger (500K each) and SSD threshold scan for Fujii / Sato
  the following beam current: 0.5, 1.0, 1.5, and 2.0 mA. Fujii / Sato
  Check and record needed hodoscope threshold at each current. Fujii / Sato
  i. Analyze:  
  1. Split-Pole focal plane profile, missing or hot channels, acceptance Fujii /Sato/Tohoku
  2. SSD and hodo rates as a function of beam current Fujii /Sato/Tohoku
  3. Threshold dependence with beam current (leakage current effect) Fujii /Sato/Tohoku
  4. SSD and hodo correlation and mapping check Fujii /Sato/Tohoku
  5. SSD and hodo efficiencies as a function of beam current Fujii /Sato/Tohoku
  6. Extract SOS positrons and check b resolution Jinghua/Yuan/Murad
  7. Check coincidence time (both arms with b=1 particles) Fujii /Sato/Tohoku
  8. Hodoscope pulse correction and timing resolution Fujii /Sato/Tohoku
  9. Path length correction parameter for each hodoscope Fujii /Sato/Tohoku
  10. Check timing resolution as a function of beam current Fujii /Sato/Tohoku
  11. First look at the optimization of the luminosity Fujii /Sato/Tohoku
  j. Check SOS detector system performance. Hamlet/Yerevan
II.2 Part 2. SOS Optics  
  Target: BeO. Posted 1.953 GeV HNSS setting. Current: 1mA Ent / Yuan
  Fast energy lock on Hall A. Hall C fast position lock on. No Raster.  
  a. Change SOS collimator to sieve slit.  
  b. Take sieve slit runs for a total of 600K triggers.  
  c. Extract updated reconstruction matrix elements  
  (Not necessarily the finalized version)  
  d. Evaluate construction quality at the current level.  
  e Continue to check on SOS detector performance Hamlet/Yerevan
  f. Evaluation of the beam quality monitoring system Gan / Gueye
  g. Continue to check on HNSS detector performance Tohoku
II.3 Part 3. Backgrounds Jinghua
  Target: Empty. Posted 1.953 GeV HNSS setting. Current: 1mA Ent
  Fast energy lock on Hall A. Hall C fast position lock on. Murad
  a. Ensure no raster.  
  b. Change SOS collimator to Large.  
  c. Take Empty target runs w and w/o Splitter magnet.  
  d. Check background in HNSS by looking at the hodoscope rate change.  
  e. Turn off Split-Pole. Tang
  f. With OTR in, use the 12.7 mm wire to study the profile. Ent / Tang
  h. With OTR out, repeat the step f to determine the effect of OTR on Ent / Tang
  beam spread.  
II.4 Part 4. SOS KID I Jinghua
  Target: BeO. Posted 1.953 GeV HNSS setting. Current: 1mA Yuan / Murad
  Fast energy lock on Hall A. Hall C fast position lock on. Hamlet / Yerevans
  a. Take a run with SOS 3/4 trigger (No PID) for 1M triggers  
  b. Study e+/h+ ratio in offline using shower counter and GC ADCs cuts  
  c. Add GC veto into trigger.  
  d. Take a run with about 200K triggers.  
  e. Study e+/h+ ratio in offline again.  
  (1) Obtain the e+ online rejection rate by GC veto  
  (2) Compare to step b GC ADC cuts  
  (3) Need minimum 97% online rejection. Adjust GC threshold if needed.  
  f. Offline study Lucite number of PE distribution (individuals and sum): Jinghua/Yuan/Murad
  (1) Gain matching; (2) rang of NPE; (3) NPE (sume) vs b  
  g. Offline study Aerogel number of PE distribution (SUM): Jinghua/Yuan/Murad
  (1) NPE vs b; (2) range of NPE.  
  h. Add Lucite into trigger (coincidence) with minimum threshold.  
  i. Take a series of runs (20 min) with different LC threshold settings.  
  j. Offline study on:  
  (1) b vs threshold settings;  
  (2) Rejection rate of low b particles and effect on the K+ region.  
  (3) A calibration of threshold to NPE cut. (1 PE = ? Threshold) Jinghua/Yuan/Murad
  (4) Will 1 PE threshold setting work in rejecting >50% protons?  
  k. Add Aerogel veto into trigger.  
  l. Take a series of runs with different threshold settings starting from high.  
  m. Offline study on: Jinghua/Yuan/Murad
  (1) e+ and p+ rejection rates; (2) Effect on K+;  
  (3) Determine the proper threshold.  
III Beam Energy: Finalization of SOS and HNSS  
  HNSS Settings: Splitter = 1.593514 T / 454.604 A, Split-Pole = 1.599816 T / 398.75 A  
  SOS D Settings = 1.31398 GeV/c, SOS Q Settings = 1.31398 x 0.915 = 1.202 GeV/c  
  Reaction: O(e,e'K+) and p(e,e'K+)  
III.1 Target: BeO. SOS KID II. Reverification of what we understood. Sato/Fujii/Jinghua
  I = 1 mA. SOS large collimator. No Raster. O(e,e'K+) kinematics.  
  a. Two Runs with SOS 3/4 + determined KID (1 hour each): Jinhua/Yuan/Murad
  (1) 0.8 mA; (2) 1.2 mA (Depending on HNSS hodo and SSD limit)  
  b. Offline study on: Jinhua/Yuan/Murad
  (1) Verify the performance of the online hardware KID (trigger);  
  (2) Study coincidence timing resolution;  
  (3) S/A ratio for K+ after offline b separations vs beam current.  
  f. Continue to check on the performance of SSD and HNSS hodoscopes Sato/Fujii/Tohoku
  in this period.  
III.2 Target: CH2. HNSS Focal Plane Calibration. Fujii/Sato
  I = 1 mA?. SOS large collimator. Raster (+/- 2.2x1.1 mm^2) !!! Tohoku
  Fast energy lock on Hall A. Hall C fast position lock on.  
  p(e,e'K+)L kinematics.  
  a. With BeO target, Harp scan to verify raster size before change to CH2. Gueye / Gan
  b. Take CH2 target runs for 24 hours or have at least 150 K events in the Tohoku
  L peak.  
  c. Calibrate x vs Pe'. Tohoku
  d. Estimate the time needed for short energy calibration run with a minimum Tohoku
  of 500 events total in the L peak.  
  e. L peak width in the missing mass spectrum after the HNSS FP calibrated. Tohoku
  Is it about 3 MeV (FWHM)?  
  f. Is HNSS detectors aligned OK? DP (SOS) vs DP (HNSS). Tohoku
III.3 Target: BeO. Production Tryout (If 8 hours or more left) Jinghua / Murad
  I = 1 mA?. SOS large collimator. No Raster. O(e,e'K+) kinematics. Yuan
  a. Change to BeO target.  
  b. Take optimized beam current (hodo capability and checked S/A ratio).  
  c. Run for O(e,e'K+) production for the rest of the time with this beam.  
     
     
  Notes:  
     
  Due to the time variation, we will not have fixed shift time for this commissioning  
  period. The listed persons who are responsible or participate in the planned  
  activities must be on call and provide us the contact phone numbers. The  
  coordinator will contact the next party at least 2 - 4 hours ahead of time.  

Last Updated on 2/22/00
By Liguang Tang