PostTargetRecoveryRunPlan
From PREX Wiki
- Once the target cool down started and D. Meekins gives "Go", start ramping up HRS magnets
- Start with all detector HVs off
- Start a new fresh slug for the production to separate the data from the previous target
Beam Restoration
- establish tune beam and low current CW beam in the hall.
- Establish beam to dump
- Design match to hall expected as part of original configuration
- Verify spot size at the target from harp trace
- Before the ion chamber calibration, check target alignment (low current, take spot runs)
- ion chamber calibration to 30uA on Ca40, Carbon, Pb (anything else?). Set beam to the collimator center
- Ramp current slowly to 150uA on Ca40, check if the trip point makes sense
- this involves target burn-off
- If Yves is available, tune beam through Compton chicane
- Do PQB check when we have beam in the hall
Low current checkout
1. Target verification and raster check
- Verify cold target positions and raster size
- Carbon hole, 1-2uA, 4x4 raster, turn ON S0 HVs, BPM A and E (x=, y=)
- Take spot runs, verify the hole and 2x2 raster size (Carbon hole radius :2mm)
- If don't find the carbon hole, adjust BPM positions and raster size
- Move to Ca40, 4x4 raster, find the target center position (move beam to see the edge and estimate the center). Log it.
- Center beam to colimator center, 2x2 raster, verify nothing hitting edges, uniform distribution from spot runs
- Move to Ca48, 4x4 raster, find the target center position. Log it.
- Center beam to collimator center, 2x2 raster, verify nothing hitting edges, uniform distributions from spot runs
2. Detector alignment check (do we need it?)
- Request escorted access if the detector mode is not in counting mode
3. Q2 measurement
- Check magnet setting is right
- Make sure VDC HVs OFF
- Beam centered at collimator, 2x2 raster
- Ask <1uA, adjust current to have S0 trigger rate ~100kHz to turn on VDC HVs
- Take 3M events
High current checkout
1. Target burn-off During this procedure,
- Verify the data while taking each run
- Check if the ion chamber trip point is sensible
- Insert Ca40 target
- 50uA, 2x2 raster, take 30min run
- 100uA, 2x2 raster, take 30min run
- 150uA, 2x2 raster, take 30min run
- Insert Ca48 target
- 50uA, 2x2 raster, take 30min run
- 100uA, 2x2 raster, take 30min run
- 150uA, 2x2 raster, take 30min run