PS-BGI Operational Readiness

Thursday 18 Feb 2021, 09:30 → 10:00 Europe/Zurich

Quick chat to figure out the final details for the PS-BGI instruments

Agenda

Schedule

https://asm.cern.ch/schedules/calendar?type=CPS%20Beam%20commissioning&schedule=CPS%20Beam%20Commissioning%202021&version=1.0&state=Draft&view=month

• First beam: March 1
• BPM commissioning: March 3 - 4
• BGI magnet H/V orbit closure: March 5
• BGI setup: March 5 - March 10
• SEMGrid multiturn + BGI test: March 11

Important note: For the BGI setup we need beam in the PS + the BGI magnets at their nominal working point

Instrument hardware

• NOTE: BGIH magnet has been running at ~80 A last couple of weeks, 176 A is the nominal. Check before first beam (OP)
  • Both BGIH and BGIV magnets have been tested. BGIH working at DC, BGIV pulsing ok 
• Replacing HV crate at PR.BGI84 (New crate ready to be installed ~Feb. 22) (BGI team)
  • Notified about impact and access next week at the same time as other accesses

Instrument setup

BGI magnet orbit correction (Matt, Alex)

• BGIH - use correction parameters from 2018
  • Expect no major difference in these parameters caused by the renovated main magnets in the PS during LS2
• BGIV - find parameters as soon as BPMs are working

Gas injection

• Ar gas bottles missing in tunnel, issue with order. New urgent delivery requested.
• Verify that the system is working, i.e. that it injects gas without disturbing the PS and the beam (OP)
  • Check with Jose March 23 how to use the gas injection system
• Check gas ionisation rate change inside the BGI with gas injection -> Requires beam (Hampus)

Calibration of timing (Hampus)

• Check and calibrate timing as soon as first beam passes through the BGI instrument
  • PIX.WRF should have a stable phase for a given beam derived from the PSB
  • PPM property "delayFromRFwarningToFirstTurn_rfclock" is used to compensate for delay to first turn at the BGI + cable delays

BGI setup (Hampus)

• Verify the functionality of the instruments: beam -> gas ionisation -> magnet/HV -> detector -> readout -> profile
• Adjust instrument settings until we get a good profile

Operational software

• BGI OP GUI: https://gitlab.cern.ch/acc-co/cps/bgi (Marcel/OP)
• BGIPXL JAPC python class: https://gitlab.cern.ch/abt-optics-and-code-repository/commissioning-tools/cern-general-devices/-/blob/master/cern_general_devices/bgi.py (Matt)
• BGIPXL FESA class (Steen)
  • profileMeasurementStart = 0 will be used to indicate the first turn