Tune Electron Beam

Tune Electron Beam (Time estimate: 15 days)

• Goal: provide a clean electron beam through the center of the beam aperture to the beam dump in the tagger hall with acceptable radiation levels.
• Priority: High
• Link to the accelerator test plan for electron beam commissioning (ATLIS)
• Expected duration:

1. Sept 19 - Sept 29: Tune beam to Hall D line dumplette (Tagger Hall can remain open).
2. Sept 29 - Oct 3 2014: Tune beam to Tagger Hall D (Tagger Hall and Hall D must be closed).

• Prerequisites:

1. Tagger microscope (TAGM) and all the crates with electronics should be removed from Hall D.
   • Responsibility: Hall D technical staff/Tom Carstens $\Box$
2. Goniometer in the beam-open position. The goniometer will not be used during the 2014 run
3. Amorphous radiator ladder equipped (HARP included) and operational
   • Responsibility: Hovanes Egiyan. $\Box$
   • Procedure for radiator harp scans
4. Beam lines under vacuum
5. Tagger magnet operational
6. Shielding walls installed
7. Radiation monitors installed and operational
8. Primary collimator block in the position between two holes, shielding the central area of the beam pipe. Secondary collimator removed.
9. Profiler counter installed in front of the collimator

• Conditions:

1. Pulsed beam pulsed beam 4-10 µA (average 60-150 nA) for the beam tune
2. CW beam 50-100 nA at the final stage of the procedure
3. No radiator
4. Hall D quadrupole magnet MQPAD00 turned off
5. Hall D/Tagger Hall locked
6. No shift workers in Hall D; experts from Hall D are involved with the radiation measurements

• Activities:

1. Tune the pulsed beam to the dump, check the beam specifications, send the CW beam (accelerator).
2. Check radiation levels in the tagger hall (Hall D/RadCon).
3. Check for photons (with the Profiler and Active Collimator) and radiation levels in the collimator cave (Hall D/RadCon).

• Responsibility: Main: Accelerator; support: HallD, RadCon.