Difference between revisions of "Tune Photon Beam"

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(→‎Tune Photon Beam)
(→‎Tune Photon Beam)
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#* Verify that beam is acceptable (Hall D)
 
#* Verify that beam is acceptable (Hall D)
 
#** [https://hdops.jlab.org/wiki/index.php/beam_table_fall14 Table of beam characteristics]
 
#** [https://hdops.jlab.org/wiki/index.php/beam_table_fall14 Table of beam characteristics]
−
#* <span style="color:#ff00ff">Procedure for verifying that the beam is acceptable on the Hall D side </span>
+
#** <span style="color:#ff00ff">Procedure for verifying that the beam is acceptable </span>  
−
#**
+
# (High) Insert the 1.7&middot;10<sup>-5</sup> R.L. <math>\Box</math>
−
# (High) Insert the 1.7&middot;10<sup>-5</sup> R.L. and check the radiation levels in the Tagger Hall and the Collimator Cave (Hall D/Accelerator)
+
#* Responsibility: Hovanes Egyian
−
# (High) Using the Profiler find the beam center position with respect to the nominal position (Hall D)
+
#* <span style="color:#ff00ff">Procedure for inserting radiator </span>
−
# (High) MCC moves the beam to the nominal position, separately in 2 projection, using the last corrector. Calibrate the predicted position vs the position provided by the Profiler. (Hall D/Accelerator)  
+
# Check the radiation levels in the Tagger Hall and the Collimator Cave <math>\Box</math>
 +
#* Responsibility: Alexandre Deur (CARMS)/Hovanes Egyian (halo counters)
 +
#* <span style="color:#ff00ff">Procedure to monitor CARMs </span>
 +
#* <span style="color:#ff00ff">Procedure to monitor Halo Counters </span>
 +
# (High) Using the first Profiler find the beam center position with respect to the nominal position (Hall D) <math>\Box</math>
 +
#* Responsibility: Hovanes Egyian
 +
#* <span style="color:#ff00ff">Procedure for getting beam position with first profiler</span>
 +
# (High) Adjust photon beam position while keeping  e<sup>-</sup> beam centered on tagger dump.
 +
#* Ask MCC to move the beam to the nominal position, using the last e<sup>-</sup> beam line corrector. <math>\Box</math>
 +
#* Calibrate the predicted position vs the position provided by the Profiler. (Hall D/Accelerator) <math>\Box</math>
 +
#* Monitor that the electron beam position at the Tagger dump remains acceptable <math>\Box</math>
 +
#* <span style="color:#ff00ff">Procedure to check that e<sup>-</sup> beam is centered on Tagger dump </span>
 +
#* Keep monitoring radiation levels in the Tagger Hall and the Collimator Cave <math>\Box</math>
 
# (High) Check the electron beam position at the Dump using the second Beam Profiler (Hall D/Accelerator)
 
# (High) Check the electron beam position at the Dump using the second Beam Profiler (Hall D/Accelerator)
 
# (High) Move the collimator 5 mm hole in X, &plusmn;30 mm around the center in order to calibrate the Active Collimator X-response. Leave the collimator in the nominal position (0.5 mm hole at the nominal center)  (Hall D)
 
# (High) Move the collimator 5 mm hole in X, &plusmn;30 mm around the center in order to calibrate the Active Collimator X-response. Leave the collimator in the nominal position (0.5 mm hole at the nominal center)  (Hall D)

Revision as of 15:16, 14 August 2014

Main Page

Tune Electron Beam

Tune Photon Beam

  • Goal: Tune the photon beam to go through the collimator, the experimental target area, and into the photon beam dump.
  • Expected Schedule:
    • Oct 4 - Oct 5 (Initial photon beam and detector checkout): 2 days
    • Oct 6 - Oct 11 (re-install tagger electronics. Tagger Hall and Hall D open): 6 days
    • Oct 12 - Oct 31 (Finalize photon beam commissioning. Detector commissioning): 20 days
  • Responsibility: HallD, Accelerator, RadCon.
  • Priority: Most activities are High, but includes Moderate and Low priority activities.
  • Prerequisites:
  1. Tagger hall equipment remain removed. \Box
  2. Hall D controlled quadrupole MQPAD00 remained turned off. \Box
    • Responsibility: MCC
  3. Hall D: Detectors turned off. Exceptions: Profiler, possible BCAL, outer rings of the FCAL \Box
  4. Monitoring available in counting room:
    • control screens \Box
    • alarm handlers \Box
    • relevant MCC screens \Box
    • Procedure for bringing up control/MCC/alarm screens
    • Responsibility: David Lawrence.
  5. Scaler acquisition operational for rate azimuthal asymmetry monitoring and initial detector study. \Box
  6. Collimator: remains in blocking position (similar to the electron beam tune phase). \Box . The motion must be calibrated. \Box
    • Responsibility: Hovanes Egiyan.
    • Procedure for moving primary radiator
  7. First profiler installed in the Collimator Cave, surveyed in order to find the position of the nominal beam center \Box
  8. Second profiler installed in front of photon beam dump, surveyed. \Box
  9. Active Collimator operational. \Box
    • Responsibility: Richards Jones
    • Procedure for monitoring beam position with the Active collimator
  10. Pair spectrometer field on, converter retracted. \Box
    • Responsibility: Alexander Somov
    • Procedure for turning on Pair Spectrometer field
    • Procedure for inserting/removing converters
  11. Solenoid on with quench-safe current ~300A.
    • Responsibility: Yi Qiang \Box
    • Procedure for monitoring and controlling Soleinoid current
  12. No target in place (air and material along the beamline makes a few R.L.). ☑
  • Activities (First period: Initial photon beam and detector checkout)
  1. (High) Re-establish the CW electron beam 50 nA to the Tagger Dump (Accelerator)
  2. (High) Insert the 1.7·10-5 R.L. \Box
    • Responsibility: Hovanes Egyian
    • Procedure for inserting radiator
  3. Check the radiation levels in the Tagger Hall and the Collimator Cave \Box
    • Responsibility: Alexandre Deur (CARMS)/Hovanes Egyian (halo counters)
    • Procedure to monitor CARMs
    • Procedure to monitor Halo Counters
  4. (High) Using the first Profiler find the beam center position with respect to the nominal position (Hall D) \Box
    • Responsibility: Hovanes Egyian
    • Procedure for getting beam position with first profiler
  5. (High) Adjust photon beam position while keeping e- beam centered on tagger dump.
    • Ask MCC to move the beam to the nominal position, using the last e- beam line corrector. \Box
    • Calibrate the predicted position vs the position provided by the Profiler. (Hall D/Accelerator) \Box
    • Monitor that the electron beam position at the Tagger dump remains acceptable \Box
    • Procedure to check that e- beam is centered on Tagger dump
    • Keep monitoring radiation levels in the Tagger Hall and the Collimator Cave \Box
  6. (High) Check the electron beam position at the Dump using the second Beam Profiler (Hall D/Accelerator)
  7. (High) Move the collimator 5 mm hole in X, ±30 mm around the center in order to calibrate the Active Collimator X-response. Leave the collimator in the nominal position (0.5 mm hole at the nominal center) (Hall D)
  8. (Moderate) If the Active Collimator data provides a better position accuracy - move the beam in X accordingly (Hall D/Accelerator)
  9. (High) Move the beam in X ±10 mm around center, verify the Active Collimator response (Hall D/Accelerator)
  10. (High) Move the beam in Y ±10 mm around center, calibrate the Active Collimator response (Hall D/Accelerator)
  11. (Moderate) If the Active Collimator data provides a better position accuracy - move the beam in Y accordingly (Hall D/Accelerator)
  12. (High) Install a PS foil converter, turn on the low-granularity PS counters, measure the coincidence rate of two arms (Hall D)
  13. (High) Using the PS wire scanner and the PS coincidence rate measure the position of the beam spot at the converter (Hall D)
  14. (High) Insert a PS foil converter, turn the PS detectors on and start taking data - keep the PS running (Hall D)
  15. (High) Control access: move the Profiler to the location in front of the Solenoid (Hall D)
  16. (High) Re-establish the beam and measure the position at the Profiler (Hall D)
  17. (High) Compare the beam position measurements. Consider moving the collimator from the nominal position if deviations of >5 mm are observed (Hall D)
  18. (High) Re-calibrate the Active Collimator in X (use the slide) and Y, without the Profiler in front (Hall D).
  19. (High) Move the collimator 5 mm hole in X, ±30 mm around the center in order to calibrate the Active Collimator X-response. Leave the collimator in the nominal position (0.5 mm hole at the nominal center) (Hall D)
  20. (Moderate) Request control access, rotate the Active collimator by 90 degree. To rotate collimator should take about 5min. Accessing the Hall, leaving it and requesting beam should take 1h. Assumed total time: 2h. (Hall D)
  21. (Moderate) Move the collimator 5 mm hole in X, ±30 mm to calibrate the Active Collimator Y-response. Leave the collimator in the nominal position (0.5 mm hole at the nominal center) (Hall D)
  22. (Moderate) If the Active Collimator data provides a better position accuracy - move the beam in Y accordingly (Hall D/Accelerator)
  23. (High) Turn on the Start Counter (ST). Check the rate asymmetry (Hall D)
  24. (Moderate) Move the collimator ±10mm and check the rates on the ST (Hall D)
  25. (High) Set the solenoid current to 1000 A (Hall D)
  26. (High) Turn on the detectors one by one from the periphery to the center monitoring the rates without and with the beam (Hall D)
  27. (High) Control Access: install the cup target (2mm and 7mm thick) into the central position in Z (Hall D)
  28. (High) Re-establish beam (Accelerator)
  29. (High) Verify the standard BCAL vs FCAL trigger (timing and thresholds) - about 4h (Hall D)
  30. (High) Take 1 shift of data (Hall D)
  31. (Medium) Measure the rates and radiation levels with the 11·10-5 R.L. radiator

One Week Pause in Running

Collect Beam Data for Detector Checkout

Optimize Detector Settings

Drift Chamber Alignment

Collect More Regular Data

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