Fall 2014 Commissioning Plan

From Hall D Ops Wiki
Jump to: navigation, search

This page gives the run plan for the Fall 2014 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 Fall 2014 commissioning.

  • Goals for the Fall 2014 run (expected durations are given in parenthesis)
    1. See start dates in the run coordination meeting pages here
    2. Clean tune of the electron beam into the Tagger Dump (13 days)
    3. Commissioning of the unpolarized photon beam (4 days)
    4. Reinstall Tagger electronics (6 days)
    5. Commissioning of the Hall D equipment under "soft" conditions (17 days):
      • Low-intensity unpolarized photon beam <10 MHz/GeV at the endpoint
      • Thin solid targets instead of the regular liquid hydrogen target
      • Solenoid current 1200 A instead of the nominal 1300 A
  • Schedule and Hall Availability: The tentative plan is:
    1. Accelerator: beam recovery and 5.5 pass beam tune to the dumplette Oct 08-17. Hall D/Tagger are open.
    2. Accelerator: electron beam tune to the Tagger Dump, 17-oct-14 - 21-Oct-14. Hall D/Tagger are locked. TAGM and the electronics are removed from the Tagger Hall.
    3. Accelerator/Hall D: Photon beam tune to Hall D and the initial equipment checkout, Oct 22-26. Halls are locked.
    4. Hall D: Re-installation of the Tagger equipment (TAGM and the electronics), Oct 27- Nov 02. Halls are open.
    5. Hall D: Equipment commissioning with photon beam, Nov 03-18. Halls are locked.
  • Expected Staffing and responsibilities:
    • The Run Coordinator (RC, Alexandre Deur) oversees the commissioning.
    • The Physics Division Liaison (PDL, Yi Qiang) and Hall D Work Coordinator/Safety Warden (T. Carstens) verify that the proper safety rules are followed.
    • The Analysis Coordinator (Paul Mattione) 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
      • Online Shifts (Nominally 2 persons per shift, one with solenoid training.):
        • Electron beam commissioning: Shifts will be scheduled but be stand-by shifts by default. The counting room will be manned only if accelerator needs a contact, or if Hall D expertise is needed to support the beam tuning (e.g. to operate the amorphous collimator harp). If so, the shift leader will be asked to be present. If the task demands it, the two-man rule must be obeyed.
        • Photon beam commissioning: Only beam line equipment and the solenoid will be operated. The detectors will be turned off for most of the time, with the possible exception of BCAL and the outer rings of FCAL. The counting room will be manned by two shift persons, one with solenoid training, and the experts necessary to the conduct of specific parts of the run plan. The RC will assign the experts. The third shift taker will be on stand-by.
        • Initial detector testing with the tagger equipment still removed: Once the photon beam is commissioned the Hall D detectors will be turned on, Online shifts will be operated by three persons, one with solenoid training.
        • Re-installation of the tagger equipment: Shifts are on stand-by.
        • Detector commissioning : Online shifts will be operated by three persons, one with solenoid training.
      • Offline Shifts: None.
  • Coordination Activities:
  • Activity Priority
    • High: Activity should be completed, contingencies in place for issues.
    • Medium: Desirable to complete the activity.
    • Low: Activity would be useful if time permits us to do it.
  • Activities planned for the next run in Spring 2015:
    • Installation and operations of the liquid hydrogen target.
    • Installation and operation of diamond radiators in goniometer.
    • Running at 1300A solenoid current.

Beam Configuration Parameters

  • Energy of Beam: expected ~ 10.1 GeV
  • Beam current:
    • Electron beam tuning is done with pulsed beam 4-10 µA, duty cycle 1.5%, average current 60-150nA (see the tune beam description here)
    • Photon beam operations: CW 50-200 nA
  • Radiators:
    • 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
  • The commissioning targets are disks of 3.19 cm diameter. Only one disk can be installed at a time. The z-position of a disk can be moved 12 cm downstream to 32 cm upstream relative to the nominal Hall D cryotarget center (60 cm downstream of the downstream end of the upstream solenoid end-cap). The available disks are:
    • 10mm thick disk of CH2 (HDPE, high density polyethylene, density 0.93-0.97 g/cm3 ), 0.95 g/cm2, ~1.2% R.L.
    • 2mm thick disk CH2 (HDPE)
    • 2mm thick inside a 20mm diameter area and 7mm thick outside (HDPE)
    • 3.4mm thick graphite 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

Commissioning time chart:
Commissioning time chart. Time t=0 corresponds to the Hall being locked-up for beam tunning. With the present schedule, it is sometime in the first half of Oct. The horizontal scale is the time during which beam is available (in other word, it would be the real time with 100% of beam efficiency). The task time estimates given on the plot have 100% contingency.

Tune Electron Beam

Tune Photon Beam and collect data for initial detector checkout

One Week Pause in Running

Finalize Photon Beam Commissioning and Optimize Detector Settings

Drift Chamber Alignment

Collect More Regular Data

Post-thanksgiving period