Latest revision as of 16:28, 26 November 2018

This page gives the run plan for the Spring 2015 commissioning. It is a controlled document that can be edited only by E. Chudakov, E. Smith or A. Deur. Suggestions and comments should be send to them.

Items in pink indicate missing information.

General Information

This document describes the run plan and procedures for the Hall D spring 2015 commissioning.

• Schedule for the Spring 2015 run. (Dates are according to the Schedule. They will be updated if necessary in the run coordination meeting pages)
  1. Feb. 13 - Feb. 26: Beam restoration (13 days)
  2. Feb. 27 - March 26: Accelerator development. Physics running conditions are similar to Fall 2014: Accelerator has priority. Possible running for Halls A/B/D.
  3. March 27 - April 2: Commission 5-pass separator.
  4. Apr. 3 - May 4: Physics run (Halls A/B/D).
• Goals for the Spring 2015 run.

1. Commission the new Hall D equipment:
   • LH2 target, high priority. ( Expected time ?? )
   • Diamond radiator/goniometer, high priority. ( Expected time ?? )
   • Accelerator RF timing, low priority. ( Expected time ?? )
   • Total Absorption Counter (TAC), low priority. ( Expected time ?? )
   • Photon beam polarimeter, low priority. ( Expected time ?? )
2. Establish that we can run with Solenoid at 1300A (implies ramping it up to 1350A).
3. Establish DAQ operation in Block Mode with ~ 20 kHz rate, high priority. ( Expected time ?? )
4. Complete detector calibration/alignment, high priority. ( Expected time ?? )
5. Complete trigger optimization, high priority. ( Expected time ?? )
6. Commission beam stability feedbacks. ( Expected time a day ?? )
7. Test diamond on 3.4mm hole, low priority. ( Expected time ?? )
8. Commission beam stability feedbacks. ( Expected time ?? )

• Expected Staffing and responsibilities:
  • The Run Coordinator (RC, Alexandre Deur) oversees the commissioning.
  • The Physics Division Liaison (PDL, Benedikt Zihlmann) and Hall D Work Coordinator/Safety Warden (T. Carstens) verify that the proper safety rules are followed.
  • The Analysis Coordinator (TBD) will organize the off-line analysis effort.
  • Individuals responsible for each commissioning step are named in the section describing the step. They are also responsible for logging in the ELog the summary of how the step proceeded and other relevant information.
  • Shifts
    • 2 persons per shift, one with solenoid training
• Coordination Activities:
  • The RC will attend the MCC meetings at 7:45am and 8:00am and the weekly MCC meeting (Wednesday, 1:30pm). The PDL will attend the weekly MCC meeting.
  • Daily run meetings broadcasted on Bluejeans will occur at 8:45am in the counting house conference room. The Run Coordinator will be responsible for organizing and chairing the meeting.
• Useful links:
  • Accelerator schedule
    • CEBAF 12 GeV Commissioning calendar
    • Scheduled Accelerator Down (SAD)/Maintenance Calendar
    • http://accboard.acc.jlab.org/
  • Links to beam parameters/radiation level monitoring:
    • Last 8-hours plots showing 1-minute, 10-minute, and hourly averages
    • Same but Last 24-hours
    • Same but Last 72-hours
    • Week, month, and quarter (3 months) plots also exist, with similar web addresses.
    • A map of the radiation monitors

Beam Configuration Parameters

• Beam energy: expected: 10 to 11 GeV
• Solenoid current up to 1300A (running condition).
• Beam current for Photon beam operations: CW 50 na-1 μA. 250 MHz frequency.
• Radiators:
  • Nominal: Diamond, 3 test diamonds (J1a50, J2a100 S145-S90) and 3 test foils (two 10 μm Al foils, and one 100 μm Al foil with a holed 10 μm Al foil pressed on it (3mm hole)).
  • Other available:
    • 1.64 µm Al (1.86·10^-5 R.L., see study)
    • 10 µm Al (11.2·10^-5 R.L.)
    • 30 µm Al (33.7·10^-5 R.L.)
• Collimator hole: 5 mm diameter nominally. May run on the 3.4 mm once priority plans are completed.
• Main target: LH2 cryogenic target
  • Backup targets are are:
    • 10mm thick disk (3.19 cm diameter) of CH₂ (HDPE, high density polyethylene, density 0.93-0.97 g/cm³ ), 0.95 g/cm², ~1.2% R.L.
    • 2mm thick disk (3.19 cm diameter) CH₂ (HDPE)
    • 2mm thick inside a 20mm diameter area and 7mm thick outside (HDPE)
    • 3.4mm thick graphite (3.19 cm diameter) disk, 0.75 g/cm², 1.8% R.L.
    • Al. cross made of 1.59 mm diameter wires
    • 1cm long Al. cylinder with an equilateral triangle hole inside. The triangle edge lengths are 2.5 cm

Run Plan

Restore Electron Beam

• Accelerator responsibility.
• If Hall D tagger is used as a dump for CW beam during electron beam restoration then
  • Hall D RC must be notified.
  • Radiator, both amorphous AND diamond, must be retracted. Collimator should be in blocking position.
  • Radiation levels should be closely monitored by MCC crew.
    • Typical levels are (for radiator retracted, collimator fully blocking, electron beam current 50 nA)
      • RAD102_P1 ~ 3 mrad/hr (tagger area, gammas, between tagger and dump)
      • (RAD102_P2 ~ 15 mrad/hr (tagger area, gammas, near electronics racks) This probe is now shielded and hence should see less radiations than during the Fall 2014 run.)
      • RAD102_P3 ~ 0.005 mrem/hr (tagger area, neutrons, near electronics racks)
      • RAD101_P1 < 0.01 mrad/hr (collimator cave, gammas). This probe is now shielded and hence should see less radiations than during the Fall 2014 run.
  • Hall D tagger CARMS, Ion Chamber and BLM threshold for beam trips should not be changed without approval of Hall D leader.

During beam restoration, Accelerator will commission our beam position/energy locks (slow feedback at about 1Hz). (Note: Locks requires a minimal current 30nA).

Restore Photon Beam. Expected time ?

1. Prerequisites: Amorphous AND diamond radiators retracted. Collimator should be in blocking position. Electron beam is restored and radiation levels are acceptable. Pair Spectrometer detectors/field on and its DAQ running Target status: Empty
2. Call MCC to inform them we will Insert 2*10^-5 radiator. Insert the radiator. Check the beam position on the profiler. Adjust it if necessary. x and y should be 0±0.5cm. If such adjustments are necessary, remind MCC that they should use only the last corrector (5C11A) to adjust the beam position. If the adjustment results in unacceptable e- beam position in the tagger dump, remind MCC that they should use the tagger magnet only to readjust the e- beam position in the tagger dump.
3. Insert the 5mm collimator. Check beam position on the Profiler and Active collimator. Check that radiation levels are good. Run for 7min to gather enough data for radiation level studies.
   • Typical levels are (for 2*10^-5 radiator, electron beam current 50 nA)
     • RAD102_P1= 3-10 mrad/hr (tagger area, gammas, between tagger and dump)
     • (RAD102_P2= ?10-20? mrad/hr (tagger area, gammas, near electronics racks) This probe now has a different shielding than for Fall 2014)
     • RAD102_P3= 0.500 mrem/hr (tagger area, neutrons, near electronics racks)
     • RAD101_P1= 12.0 mrad/hr (collimator cave, gammas).
4. Hall A leakage study.
   • Make sure Hall A is running, ask MCC for which laser they are using and the opening of their slit.
   • Ask MCC to close our slit. Insert 3*10^-4. Record rates in radiation monitors and profiler (wait there 5 min).
   • If we see any rates above background, repeat previous step with 10^-4 radiator.
   • If we still see any rates above background, repeat previous step with 2*10^-5 radiator.
   • Repeat previous step with 2*10^-5 radiator.
5. Radiation level studies (0.5h):
   • Run 7 min without radiator (Call MCC and ask to mask the FSD each time the radiator is moved). Beam current: 50nA
   • Run 7 min with the 10^-4 radiator (Call MCC). Beam current: 50nA
   • Run 7 min with the 3*10^-4 radiator (Call MCC). Beam current: 50nA
   • Insert the 2*10^-5 radiator (Call MCC).
6. Determine maximum photon beam transmission by doing 2D scans (x: beam scan, y: beam scan. ±5cm with 0.5cm steps). Meanwhile, monitor the rate at the active target and rates (including coinc.) in the pair spectrometer.

Ramp-up solenoid/Test target controls under magnetic field (4h) DONE

Contact Target group before ramping up magnet. (Number is on the white board) This may require controlled access (check with target group and Mechanical on call).

Verify subsystems under beam condition. 2 shifts

Target is nominally empty. Solenoid at 1200A (or 300A if we are still studying the Wednesday magnet trip). If the rate is not large enough with the thin radiator, put the 3.4 10^-5 radiator in and increase current to 100 nA beam. Photon should be beam optimized to max. transmission.

1. Trigger
2. DAQ
3. GlueX/Tagger detectors
   • TAGH & TAGM
   • ST
   • FCAL
   • BCAL (Include Threshold scans)
   • TOF
   • FDC
   • CDC
4. Online monitoring
   • (Pair Spectrometer): should be already running

Microscope bias voltage study: 4h NOT NECESSARY ANYMORE

• Call Alex Barnes (570-242-1844) in advance to let him know that he will be able to start the bias study.
• Conditions: 50nA, 2×10-5 radiator. Pair Spec. Trigger.
• Alex to do low/high gains studies. 2h each.

Commission cryogenic target. 28h

• Alignment verification. (26h)
  • Pre-requisite: Target is cold and empty, 3.4 10^-5 radiator in, 100 nA beam. Photon beam optimized to max. transmission. Solenoid at 1200A. Gluex detectors operational.
  1. If needed, empty the target: 15min
  2. Scan the beam horizontally with collimator:scan between ±20mm around nominal 111.7 position. Do 2mm steps. Spend 1min on each steps. Make sure the P.S. DAQ is running and the general DAQ is running. Correlate rates from S.T. and current in FDC with collimator position to verify target horizontal alignment. P.S. rate must normalize the ST and FDC rates due to the scan through the non-flat beam profile (if the fast feedback from the active target is enabled, this correction should be minimized). 2h.
  3. Run 3 shifts to gather data to verify (Simon T.) that:
  • • The distances between the various windows on the beam line are correct.
    • The ratio of the rate from each window to the solid target at the nose of the ST are correct.
• Density check (optional, 2h).
  1. Fill the target (30 min).
  2. Run with the target not subcooled, 30 min at 3 radiator thicknesses, 50 nA.
  3. Subcool the target (30min).
  4. Run with the target subcooled, 30 min at 3 radiator thicknesses.
• Verify that rates scale with radiator thickness × e- beam current.

Test goniometer control. Part 1 Expected time ?

1. Prerequiste: Warn in advance MCC that during this procedure, they will be able to determine the Ion Chamber trip limits for the various foils/diamonds of the goniometer. (So their appropriate personnel should be around.)
2. Part 1 is on test diamond (90 μm).
   • Call MCC to tell them we will scan the beam position on the goniometer to identify the foils/diamonds positions. Beam will go through the goniometer frame so the Ion Chamber should be masked.
   • Test beam position with empty holder and foils (Hovanes).
   • Tell MCC to unmask Ion Chambers.
   • Tell MCC that they can now determine the Ion Chamber trip limits for each of the foils/diamonds. This will require us to move each of them into beam position (30min).
   • Scan beam on diamond (Hovanes/Paul M.). First, use JD70-3. Then J1a50 and S145-S90. Check the difference between the three diamonds.

Trigger optimization. Expected time ?

Plan

1. Optimize triggers (Details)
2. Check DAQ with PS included in readout (1h).

DAQ tests. Expected time ?

Plan

Forward Drift Chamber Alignment. Expected time 22h

• Prerequisite: FCal+TOF trigger tested and optimized.
• Conditions: B=0, 2×10-5 amorphous radiator. I<100nA Beam current, trigger type:FCal+TOF

1. Bring down the magnetic field to 0. Ideally, it should be done opportunistically, e..g during beam studies, and determine when we will start this task: (6h)
2. Take data (Lubomir): 16h
3. Bring the magnetic field back up. 6h.

Commission fast feedbacks. Expected time ?

• Fast Feedback (1kHz feedback) will not be ready before mid-April
• Fast Feedback requires a minimal current of probably more than 50nA.

Test goniometer control. Part 2 Expected time ?

• Prerequisites:
  • Stable beam (lock commissioned and on).
  • 5 nA of beam current. MCC needs to be warned several days in advance to be able to deliver 5nA (Note: Locks requires a minimal current 30nA. Fast Feedback requires more (unknown value for now).
  • tagger hodoscope, microscope, photon and PairSpec scalers beam profiler operational.

1. Ken Livingston can start the plan remotely starting on March 23rd. He will be at JLab between Apr. 17th to Apr 30th.
2. When available, install production diamons (50 μm), preferably during opportunistic access: Time: 8h

Plan

Commission Accelerator RF timing signal.

Data will be taken during concurrently with other parts of the commissioning.

Commission Total Absorption Counter. 8h

Prerequisites: Warn MCC several days in advance that we will want to run at 5nA. (Note: Locks requires a minimal current 30nA. Fast Feedback requires more (unknown value for now).

• Stable low current beam established (I<5nA)
• Specific DAQ setup. Trigger: TagM, TagH. DAQ must include TAC and PS.

Plan

• 1. Establish a stable low current beam <5nA: 4h
  2. Take two 2h runs: 4h

Collect More Regular Data: 2-3 weeks

1. BCal: Run a shift at lower temperature (Elton) 8h.
   • Controlled access necessary to change the temperature. Assume it will be opportunistic.
   • Regular trigger. Trigger mode 7.
2. calibration data. (based on Elton's calorimeter report, here.
   • Take 6 days of good data with FCal. Assuming 50% general efficiency, this should take about 2 weeks.
   • Concurrently, take at least 3 days of good data with BCal.
   • Take 1h run in mode-8 every day. Other runs are in mode-7, so that about 90% of the data are in mode-7.
   • Trigger type ?
3. Run on diamond radiator with 3.4mm collimator hole (1 days?)
   • Request controlled access. Switch Active collimator from 5mm hole position to 3.4mm hole position (2h). Alex Barnes
   • Re-establish photon beam beam on 3.4mm collimator hole. Test Active collimator signals (2h). Alex Barnes
   • Take tagger and PS data in this configuration. Alex Somov.