Difference between revisions of "Tune Photon Beam"

Revision as of 15:52, 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:

Tagger hall equipment remain removed. $\Box$
Hall D controlled quadrupole MQPAD00 remained turned off.
- Responsibility: MCC
Hall D: Detectors turned off. Exceptions: Profiler, possible BCAL, outer rings of the FCAL $\Box$
Monitoring available in counting room:
- control screens $\Box$
- alarm handlers $\Box$
- relevant MCC screens $\Box$
- Procedure for bringing up control/MCC/alarm screens
- System expert: David Lawrence.
Scaler acquisition operational for rate azimuthal asymmetry monitoring and initial detector study. $\Box$
Collimator: remains in blocking position (similar to the electron beam tune phase). . The motion must be calibrated.
- System expert: Hovanes Egiyan.
- Procedure for moving primary radiator
First profiler installed in the Collimator Cave, surveyed in order to find the position of the nominal beam center $\Box$
Second profiler installed in front of photon beam dump, surveyed. $\Box$
Active Collimator operational.
- System expert: Richards Jones
- Procedure for monitoring beam position with the Active collimator
Pair spectrometer field on, converter retracted.
- System expert: Alexander Somov
- Procedure for turning on Pair Spectrometer field
- Procedure for inserting/removing converters
Solenoid on with quench-safe current ~300A.
- System expert: Yi Qiang $\Box$
- Procedure for monitoring and controlling Soleinoid current
No target in place (air and material along the beamline makes a few R.L.). ☑

Activities (First period: Initial photon beam and detector checkout)

(High) Re-establish the CW electron beam 50 nA to the Tagger Dump (Accelerator) (time estimate: ???)
- Verify that beam is acceptable (Hall D)
  - Table of beam characteristics
  - Procedure for verifying that the beam is acceptable
(High) Insert the 1.7·10^-5 R.L. (time estimate: 5 min)
- System expert: Hovanes Egyian
- Procedure for inserting radiator
Check the radiation levels in the Tagger Hall and the Collimator Cave (time estimate: 10 min)
- System expert: Alexandre Deur (CARMS)/Hovanes Egyian (halo counters)
- Procedure to monitor CARMs
- Procedure to monitor Halo Counters
(High) Using the first Profiler find the beam center position with respect to the nominal position (time estimate: ???)
- System expert: Hovanes Egyian
- Procedure for getting beam position with first profiler
(High) Adjust photon beam position while keeping e^- beam centered on tagger dump. Obtain a first determination of the accelerator scale. (time estimate: ???)
- Ask MCC to move the beam to the nominal position, using the last e^- beam line corrector. $\Box$
- Calibrate the accelerator scale for x and y. That is, find the relation between the corrector currents and beam position at the profiler location. Obtain this information from MCC and log it in the Electronic logbook. This provides a rough accelerator scale. The fine one will be provided by the Active Collimator. $\Box$
- 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 $\Box$
(High) Check the electron beam position at the Dump using the second Beam Profiler
- System expert: Hovanes Egyian
- Procedure for getting beam position with beam dump profiler
(High) Active collimator calibration (time estimate: ???)
- Move the collimator 5 mm hole in X, ±30 mm around the center in order to calibrate the Active Collimator X-response. Use 5mm step size. Leave the collimator in the nominal position (0.5 mm hole at the nominal center)
  - System expert: Richard Jones/Hovanes Egyian
  - Procedure for moving the primary collimator
  - Procedure for reading beam X-position from the Active collimator
- (Moderate) If the Active Collimator data provides a better position accuracy - move the beam in X accordingly (time estimate: ???) $\Box$
- (High) Ask MCC to move the beam in X ±10 mm around center. Use 2mm step size. Verify that the beam X-position from the Active Collimator matches $\Box$
- (High) Ask MCC to move the beam in Y ±10 mm around center. Use 2mm step size. calibrate the Active Collimator response (Hall D/Accelerator)
- (Moderate) If the Active Collimator data provides a better position accuracy - move the beam in Y accordingly (Hall D/Accelerator)
(High) measure the beam position with the Pair Spectrometer's harp (time estimate: ???)

Install a PS foil converter, turn on the low-granularity PS counters, measure the coincidence rate of two arms (Hall D)

(High) Using the PS wire scanner and the PS coincidence rate measure the position of the beam spot at the converter (Hall D)
(High) Insert a PS foil converter, turn the PS detectors on and start taking data - keep the PS running (Hall D)
(High) Control access: move the Profiler to the location in front of the Solenoid (Hall D)
(High) Re-establish the beam and measure the position at the Profiler (Hall D)
(High) Compare the beam position measurements. Consider moving the collimator from the nominal position if deviations of >5 mm are observed (Hall D)
(High) Re-calibrate the Active Collimator in X (use the slide) and Y, without the Profiler in front (Hall D).
(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)
(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)
(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)
(Moderate) If the Active Collimator data provides a better position accuracy - move the beam in Y accordingly (Hall D/Accelerator)
(High) Turn on the Start Counter (ST). Check the rate asymmetry (Hall D)
(Moderate) Move the collimator ±10mm and check the rates on the ST (Hall D)
(High) Set the solenoid current to 1000 A (Hall D)
(High) Turn on the detectors one by one from the periphery to the center monitoring the rates without and with the beam (Hall D)
(High) Control Access: install the cup target (2mm and 7mm thick) into the central position in Z (Hall D)
(High) Re-establish beam (Accelerator)
(High) Verify the standard BCAL vs FCAL trigger (timing and thresholds) - about 4h (Hall D)
(High) Take 1 shift of data (Hall D)
(Medium) Measure the rates and radiation levels with the 11·10^-5 R.L. radiator

@@ Line 22: / Line 22: @@
 #* relevant MCC screens <math>\Box</math>
 #* <span style="color:#ff00ff">Procedure for bringing up control/MCC/alarm screens </span>
-#* Responsibility: David Lawrence.
+#* System expert: David Lawrence.
 # Scaler acquisition operational for rate azimuthal asymmetry monitoring and initial detector study. <math>\Box</math>
 # Collimator: remains in blocking position (similar to the electron beam tune phase). <math>\Box</math>. The motion must be calibrated. <math>\Box</math>
-#* Responsibility: Hovanes Egiyan.
+#* System expert: Hovanes Egiyan.
 #* <span style="color:#ff00ff">Procedure for moving primary radiator </span>
 # First profiler installed in the Collimator Cave, surveyed in order to find the position of the nominal beam center <math>\Box</math>
 # Second profiler installed in front of photon beam dump, surveyed. <math>\Box</math>
 # Active Collimator operational. <math>\Box</math>
-#* Responsibility: Richards Jones
+#* System expert: Richards Jones
 #* <span style="color:#ff00ff">Procedure for monitoring beam position with the Active collimator</span>
 # Pair spectrometer field on, converter retracted. <math>\Box</math>
-#* Responsibility: Alexander Somov
+#* System expert: Alexander Somov
 #* <span style="color:#ff00ff">Procedure for turning on Pair Spectrometer field </span>
 #* <span style="color:#ff00ff">Procedure for inserting/removing converters </span>
 # Solenoid on with quench-safe current ~300A.
-#* Responsibility: Yi Qiang <math>\Box</math>
+#* System expert: Yi Qiang <math>\Box</math>
 #* <span style="color:#ff00ff">Procedure for monitoring and controlling Soleinoid current </span>
 # No target in place (air and material along the beamline makes a few R.L.). <span style="font-size:21px">☑</span>
 * '''Activities (First period: Initial photon beam and detector checkout) '''
-# (High) Re-establish the CW electron beam 50 nA to the Tagger Dump (Accelerator)
+# (High) Re-establish the CW electron beam 50 nA to the Tagger Dump (Accelerator) <span style="color:#ff00ff">(time estimate: ???)</span> <math>\Box</math>
 #* Verify that beam is acceptable (Hall D)
 #** [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 </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. <math>\Box</math> <span style="color:#ff00ff">(time estimate: 5 min)</span> <math>\Box</math>
-#* Responsibility: Hovanes Egyian
+#* System expert: Hovanes Egyian
 #* <span style="color:#ff00ff">Procedure for inserting radiator </span>
-# Check the radiation levels in the Tagger Hall and the Collimator Cave <math>\Box</math>
+# Check the radiation levels in the Tagger Hall and the Collimator Cave <math>\Box</math> <span style="color:#ff00ff">(time estimate: 10 min)</span> <math>\Box</math>
-#* Responsibility: Alexandre Deur (CARMS)/Hovanes Egyian (halo counters)
+#* System expert: 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>
+# (High) Using the first Profiler find the beam center position with respect to the nominal position <span style="color:#ff00ff">(time estimate: ???)</span> <math>\Box</math>
-#* Responsibility: Hovanes Egyian
+#* System expert: 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.
+# (High) Adjust photon beam position while keeping  e<sup>-</sup> beam centered on tagger dump. Obtain a first determination of the accelerator scale. <span style="color:#ff00ff">(time estimate: ???)</span>
 #* 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>
+#* Calibrate the accelerator scale for x and y. That is, find the relation between the corrector currents and beam position at the profiler location. Obtain this information from MCC and log it in the Electronic logbook. This provides a rough accelerator scale. The fine one will be provided by the Active Collimator. <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 <math>\Box</math>
-# (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)
+#* System expert: Hovanes Egyian
-# (Moderate) If the Active Collimator data provides a better position accuracy - move the beam in X accordingly (Hall D/Accelerator)
+#* <span style="color:#ff00ff">Procedure for getting beam position with beam dump profiler</span>
-# (High) Move the beam in X &plusmn;10 mm around center, verify the Active Collimator response (Hall D/Accelerator)
+# (High) Active collimator calibration <span style="color:#ff00ff">(time estimate: ???)</span>
-# (High) Move the beam in Y &plusmn;10 mm around center, calibrate the Active Collimator response (Hall D/Accelerator)
+#* Move the collimator 5 mm hole in X, &plusmn;30 mm around the center in order to calibrate the Active Collimator X-response. Use 5mm step size. Leave the collimator in the nominal position (0.5 mm hole at the nominal center)  <math>\Box</math>
-# (Moderate) If the Active Collimator data provides a better position accuracy - move the beam in Y accordingly (Hall D/Accelerator)
+#** System expert: Richard Jones/Hovanes Egyian
-# (High) Install a PS foil converter, turn on the low-granularity PS counters, measure the coincidence rate of two arms (Hall D)
+#** <span style="color:#ff00ff">Procedure for moving the primary collimator</span>
+#** <span style="color:#ff00ff">Procedure for reading beam X-position from the Active collimator</span>
+#* (Moderate) If the Active Collimator data provides a better position accuracy - move the beam in X accordingly <span style="color:#ff00ff">(time estimate: ???)</span> <math>\Box</math>
+#* (High) Ask MCC to move the beam in X &plusmn;10 mm around center. Use 2mm step size. Verify that the beam X-position from the Active Collimator matches  <math>\Box</math>
+#* (High) Ask MCC to move the beam in Y &plusmn;10 mm around center. Use 2mm step size. calibrate the Active Collimator response (Hall D/Accelerator)
+#* (Moderate) If the Active Collimator data provides a better position accuracy - move the beam in Y accordingly (Hall D/Accelerator)
+# (High) measure the beam position with the Pair Spectrometer's harp <span style="color:#ff00ff">(time estimate: ???)</span>
+Install a PS foil converter, turn on the low-granularity PS counters, measure the coincidence rate of two arms (Hall D)
 # (High) Using the PS wire scanner and the PS coincidence rate measure the position of the beam spot at the converter (Hall D)
 # (High) Insert a PS foil converter, turn the PS detectors on and start taking data - keep the PS running (Hall D)

Difference between revisions of "Tune Photon Beam"

Revision as of 15:52, 14 August 2014

Contents

Main Page

Tune Electron Beam

Tune Photon Beam

One Week Pause in Running

Collect Beam Data for Detector Checkout

Optimize Detector Settings

Drift Chamber Alignment

Collect More Regular Data

Navigation menu

Personal tools

Namespaces

Variants

Views

More

Search

Navigation

Tools