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Revision as of 10:03, 22 January 2020 by Sanghwa (Talk | contribs) (Low current checkout)

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  • 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

  1. establish tune beam and low current CW beam in the hall.
  2. Establish beam to dump
  3. Design match to hall expected as part of original configuration
  4. Verify spot size at the target from harp trace
  5. Before the ion chamber calibration, check target alignment (low current, take spot runs)
  6. ion chamber calibration to 30uA on Ca40, Carbon, Pb (anything else?). Set beam to the collimator center
  7. Ramp current slowly to 150uA on Ca40, check if the trip point makes sense
    • this involves target burn-off
  8. If Yves is available, tune beam through Compton chicane
  9. 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. 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

  • Insert Ca48 target
  • 50uA, 2x2 raster, take 30min run
  • 100uA, 2x2 raster, take 30min run
  • 150uA, 2x2 raster, take 30min run
  • Verify the data while taking each run
  • Check if the ion chamber trip point is sensible