Revision as of 18:03, 27 February 2015

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 ?? )

• 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 7:50am 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 10:30am 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, and test diamonds/foils: two test diamonds, 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:
    • 1.5 µm Al (1.7·10^-5 R.L.)
    • 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 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 61.50 nA)
      • RAD102_P1= 0.170 mrad/hr (tagger area, gammas, between tagger and dump)
      • RAD102_P2= 0.480 mrad/hr (tagger area, gammas, near electronics racks)
      • RAD102_P3= 0.080 mrem/hr (tagger area, neutrons, near electronics racks)
      • RAD101_P1= 0.001 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.

Restore Photon Beam. Expected time ?

1. Prerequisite: Electron beam is restored and radiation levels are acceptable. Target status: Empty
2. Insert 2*10^-5 radiator. Insert 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= 3.500 mrad/hr (tagger area, gammas, between tagger and dump)
     • RAD102_P2= 9.900 mrad/hr (tagger area, gammas, near electronics racks)
     • RAD102_P3= 0.500 mrem/hr (tagger area, neutrons, near electronics racks)
     • RAD101_P1= 1.0 mrad/hr (collimator cave, gammas).
3. 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).
4. Determine maximum photon beam transmission by doing 2D scans (x: motor scan, y: beam scan). Meanwhile, monitor the rate at the active target and rates (including coinc.) in the pair spectrometer.

Commission beam stability feedbacks. Expected time ?

Procedure Meanwhile, cool down the target (keep it empty): 6h

Verify subsystems under beam condition. Expected time ?

1. Trigger
2. DAQ
3. GlueX/Tagger detectors
   • TAGH & TAGM
   • Pair Spectrometer
   • ST
   • FCAL
   • BCAL
   • TOF
   • FDC
   • CDC
4. Online monitoring

Commission cryogenic target. Expected time ?

• Alignment verification. Expected time ?
  • Pre-requisite: Target is cold and empty, 3.4 10^-5 radiator in, 100 nA beam. Photon beam optimized to max. transmission.
  1. If needed, empty the target: 15min
  2. Run Expected time ? and verify 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.
  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. Part 1 is on test diamond (90 μm).
   • Test beam position with empty holder and foils</span>
   • ...

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 8h

Plan

Test goniometer control. Part 2 Expected time ?

1. Ken Livingston 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. Expected time ?

Plan

Commission Total Absorption Counter. 8h

Prerequisites.

• 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

Plan