Beam Commissioning Plan

Draft Outline for Commissioning

Review Sequence

1. Electron beam
   • OSP and small internal review in order to power and map tagger magnet
   • Transfer of tagger magnet operation to accelerator, so that it can be reviewed as part of ARR II (nominally Jan)
2. Photon beam
   • Review of photon beamline (radiator to photon beam dump). Nominally scheduled for March, at least 3 months prior to beam delivery
   • This includes review of the tagger hodoscope and microscope, profile monitor, active collimator, halo monitors, and other photon beam monitors.
3. Experimental Equipment Hall D
   • Experimental apparatus in Hall D (prior to use with beam)

Electron beam

Goals

1. Safely deliver electron beam to the electron beam dump \cite{shielding}

Assumptions

1. Accelerator has qualified the machine protection system (MPS) and the personnel safety system (PSS) for the tagger building
2. Assume steel blocks (> 20" thick) are stacked in front of the photon beam pipe to the hall to prevent any direct beam spray from traveling down to Hall D.

Checklist at low current I~1uA, tune mode

1. Check beam is centered on the beam dump
2. Scan position of beam over the area of the radiator
3. Check single rates at various positions in the tagger enclosure (electronic racks)
4. Check single rates at the location of the tagger microscope
5. Check single rates at the location of the tagger broad band hodoscope
6. Verify tagger magnet excitation curve matches predictions, e.g. for different beam energies
7. Verify controls for all beamline elements work as expected
8. Check radiation levels in the tagger hall
9. Esablish location in the hall for electronic racks safe from radiation
10. Identify sources of background (scraping) in the hall.
11. Check Fast Shutdown system

Checklist at low current I< 100 nA?, CW

1. Verify proper operation of beam as in pulsed mode
2. Check single rates at various positions in the tagger enclosure (electronic racks)
3. Check single rates at the location of the tagger microscope
4. Check single rates at the location of the tagger broad band hodoscope
5. Identify sources of background (scraping) in the hall.
6. Check out amorphous ladder controls
7. Commission halo pmts located on the electron beam pipe to the dump (i.e. adjust HV settings)
8. Change radiators and check relative thicknesses using halo pmts
9. Use accelerator harp to determine beam centroid and width
10. Use amorphous ladder harp to verify beam centroid, width and halo

Checklist at high current I>?, CW

1. Verify proper operation of beam as in low current situation
2. Check single rates at various positions in the tagger enclosure (electronic racks)
3. Check single rates at the location of the tagger microscope
4. Check single rates at the location of the tagger broad band hodoscope
5. Check radiation levels in the tagger hall
6. Check radiation levels in Hall D
7. Check radiation levels in the tagger service building

Abnormal conditions

1. High radiation levels in any or all areas of interest
2. Accidental loss of power to vertical bend string
3. Accidental loss of power of tagger magnet
4. Accidental loss of vacuum

Photon beam

Goals

1. Determine characteristics of photon beam in Hall D
2. Safely deliver photon beam through the hall to the photon beam dump

Assumptions

1. Accelerator has qualified the machine protection system (MPS) and the personnel safety system (PSS) for Hall D and the counting house
2. Delivery of electron beam through tagger to electron dump has been accomplished
3. Operation is assumed CW, but perhaps one should start with pulsed mode
4. Amorphous radiator installed with $10^{-5}$ thickness, typical
5. Steel blocking photon beam pipe in tagger hall have been removed
6. Initially the solenoidal magnet is off

Input

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