Revision as of 15:53, 10 December 2015

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

Items in red indicate missing information.

Items in pink indicate information requiring verification.

General Information

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

• Schedule for the Fall 2015 run. (Dates are according to the long term calendar. They will be updated if necessary in the run coordination meeting pages)
  1. Dec. 7th-8th Electron/Photon beam restoration (1 days)
  2. Dec. 8th-16th: Accelerator Fast Feedback commissioning and nA BPM commissioning. Meanwhile, we may parasitically conduct tagger detector tests. We may also have the beam available, typically during the night, to conduct our own commissioning.
• Goals for the Spring 2015 run.

1. Beam transport and control commissioning (accelerator responsibility):
   1. Position Fast Feedback: Trent Allison, Brian Bevins. Expected time: 40h.
   2. nA BPM: Trent Allison, Brian Bevins. Expected time: ?? h.
   3. Beam line model test: Todd Satogata). Expected time: 2 h.
2. Continue commissioning of the Hall D equipment (Hall D responsibility):
   1. Tagger detectors commissioning (Richard J. and Alex B.). Expected time: 7h.
      • Bias voltage study can be done parasitically to the FFB work.
   2. PS, tagger detectors and trigger studies (Alex S.): Expected time: needs as much data as possible. Main magnetic field is not necessary. Calorimeters, SC and TOF need to be on during theses studies. Detailed plan needed from Alex S.
   3. Trigger tests at high current (μA): Alex S.
   4. DAQ (Sergey F). Expected time: about 1h of dedicated DAQ time each day.
      • The goal is to optimize DAQ performance : data rate, trigger rate, live time. Several parameters have to be defined for every DAQ components independently: detectors readout (for FDC,CDC,FCAL,BCAL,...) , event builder, data concentrators, event recorder, to find the slowest.
      • Optimization includes different triggers and beam currents.
      • FDC/CDC will be needed for about 30min with a 50-100nA current.
      • The detectors will be running the same hardware (no new fiber bundles for Fall15) and software as the previous run.
   5. Transition radiation detector (Lubomir P. and Sergei F.). Runplan and instructions are here. Expected time: Parasitic to other Hall D activities.
   6. Calorimeters, ST and TOF will take parasitic data (for their sake and because of the trigger/DAQ studies).

• 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.
  • Shifts: 2 persons per shift. The usual requirement that at least one of the shift taker has Solenoid training is not in effect for the Fall 15 run (Solenoid field will be off).
• 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
    • long term 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 and Hall Configurations

• Beam energy expected: 12.047 GeV (1.090 GeV/linac and 0.123 GeV for the injector and -0.066 GeV of synchrotron radiation losses. This set-up should also be used for the Spring 16 run)
• Solenoid off.
• Beam current: CW 5 na-3 μA. 250 MHz frequency.
• Radiators:
  • 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.)
  • The goniometer with the diamond radiators will not be used.
• Collimator hole: 5 mm diameter.
• Target: 10mm thick disk (3.19 cm diameter) of CH₂ located on the nose of the ST. (HDPE, high density polyethylene, density 0.93-0.97 g/cm³ ), 0.95 g/cm², ~1.2% R.L.
• The LH2 target will be empty (i.e. with warm 2H gas at 1 atm.).
• Solenoid cool down: may need accesses (controlled or restricted). This interferes with accelerator operations (even without beam in Hall D) since moving from Beam Permit to Controlled or Restricted access drops the injector PSS status.
• List of devices that will not be used during the Fall 2015 run:
  • Goniometer.
  • Polarimeter.
  • Total Absorption Counter.

Run Plan

Overview

We expect a very limited amount of beam time (approx. 1 to 1.5 weeks) and will run a reduced program. The schedule of the runplan will be done once the accelerator commission plans (FFB, nA BPM) are finalized.

Tune Electron Beam

The goal is to tune the beam so that the FFB commissioning (done during day shifts) is done with a beam as close as possible to the one we will use. This entails tuning the photon beam as well. Photon beam must also be properly setup in order to carry out our commissioning during swing and owl shifts.

• Ion Chambers trip threshold must be set.<b>
• Tune electron beam with radiator retracted
  • <b>Amorphous Radiator (and diamond) must be retracted. Collimator should be in blocking position. CDC/FDC are off
  • Radiation levels should be closely monito#ff00ff 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).
      • RAD102_P3 ~ 0.1 mrem/hr (tagger area, neutrons, near electronics racks)
      • RAD101_P1 < 0.1 mrad/hr (collimator cave, gammas).
    • Record neutron radiation levels of the new neutron probe in the Hall. (Should be 0)
  • Hall D tagger CARMS, Ion Chamber and BLM threshold for beam trips should not be changed without approval of Hall D leader.
• Establish good photon beam
  • Insert 10^-5 RL radiator.

1. • Typical levels are (for 2*10^-5 radiator, electron beam current 50 nA)
     • RAD102_P1= 2-10 mrad/hr (tagger area, gammas, between tagger and dump)
     • RAD102_P2= 10-20 mrad/hr (tagger area, gammas, near electronics racks)
     • RAD102_P3= ~0.5 mrem/hr (tagger area, neutrons, near electronics racks)
     • RAD101_P1= ~10 mrad/hr (collimator cave, gammas).

Fast Feedback and nA commissioning. Beam transport and control commissioning.

• Accelerator responsibility.

• 1. The test will start at 1μA, and possibly 3μA. No radiator will be in place but, due to the nature of the commissioning, beam scrapping will certainly occur. FFB commissioning will be concluded by low current (5nA) nA-BPM commissioning.
  2. Beam line FOPT. About 2h of data. Data for beam energy stability study will be gathered at the same time.

Restore Photon Beam.

1. Prerequisites:</b> Amorphous (and diamond) radiator retracted. Collimator should be in blocking position. Electron beam is restored and radiation levels are acceptable. Optional: Pair Spectrometer detectors/field on and its DAQ is running
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. <b> 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= 2-10 mrad/hr (tagger area, gammas, between tagger and dump)
     • RAD102_P2= 10-20 mrad/hr (tagger area, gammas, near electronics racks)
     • RAD102_P3= ~0.5 mrem/hr (tagger area, neutrons, near electronics racks)
     • RAD101_P1= ~10 mrad/hr (collimator cave, gammas).

Fast Active Collimator calibration (5 min)

• Accelerator responsibility.
• Bias voltage studies can be done parasitically (4h, Alex B.)

Fast Feedback and nA commissionings

• Accelerator responsibility.

Runplan Schedule

• • • A map of the radiation monitors