ThermalBreakin

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PREX Main<< Information for Shift Takers << Shift Leader << HOW TOs

Note: these instructions may change as we learn from the target operation.

DO NOT EXCEED 100 uA on Ca-48 target without explicit instructions from the RC until further notice!

Added: should be done with a 6x6 raster

  1. Set SAM and quartz HVs for integration mode
  2. Start with Ca-40 target at 50uA
  3. Take data for 1 hour, carefully monitoring:
    • asymmetry widths
    • collimator temperatures (expect ~ W at 50uA)
    • cold ladder temperatures
    • Post screen captures to the logbook
    • Note anything out of the ordinary
    • Don't hesitate to call RC for guidance!
  4. If everything seems steady, go to 100 uA on Ca-40
    • Follow steps from 2 above
  5. If everything seems steady, go to 150 uA on Ca-40
    • Follow steps from 2 above
    • Note: they might not be able to deliver 150 uA, so just run at the highest available current up to 150uA
  6. Assuming that everything went well with the Ca-40 target, continue with following steps
  7. Move to the Ca-48 target and ask for 50 uA
  8. Take data for 1 hour, carefully monitoring:
    • asymmetry widths
    • collimator temperatures (expect ~330 W at 50uA)
    • cold ladder temperatures
  9. If everything seems steady, go to 100 uA on Ca-48
    • Follow steps from 8 above
    • Note: they might not be able to deliver even 100 uA, so just run at the highest available current up to 100uA



Explanation: The calcium oxidizes very quickly, and the presence of oil residue or an oxide layer could affect the thermal contact/conductivity so we want to carefully ablate the surface layer and make sure that we have stable target conditions to avoid damaging it with high current.