Reminder of some BCM & Post Mortem procedures for DCS Shifters:

A. There are several situations when status of the ALICE permits may change:

  • LHC injection handshake,
  • CCC (via Shift Leader) asks for giving the permits manually,
  • Post Mortem
  • arming of the Beam Permit after Post Mortem triggered by ALICE
  • manual removing of the injection permits on Shift Leader request

Shifter should verify then on the alarm screen if there is no alarm related to lhc_exchange project.

By default the manual rearming of the injection permits can be performed only if ALICE is SAFE/SUPERSAFE and CCC expects them. For some LHC tests when the injection is not planned the permits might be armed irrespective of the SAFE/SUPERSAFE state (only on Shift Leader explicit request!).

B. In case of communication problems (alarms, problem with giving the permits) the shifter can:

  • 1. Try to restore the communication using recovery button (DCS GUIDE, FOLDER)
  • 2. Check what is the true status of permits/transient recorder using manual report (on the panel ali_dcs\lhc\dcs_bcm\bcm_tell1) - upon DCS Oncall request
  • 3. Upon DCS Oncall requestl: give the permits using emergency button if CCC is expecting them (TWIKI, FOLDER)

DCS On call should be immediately informed.


Post Mortem:

  • can occur anytime
  • it implicates the injection permits are removed automatically
  • if ALICE BCM caused the beam dump then also the Beam Permit is removed
  • Post Mortem last ~ 3 minutes

After the Post Mortem the shifter should check:

  • if permits were rearmed if necessary (i.e. ALICE is SAFE and ALICE is during injection handshake)
  • if there is no alarms related with LHC exchange project (up to 6 minutes after the Post Mortem procedure started)
  • the status of the Beam Permit. If it is red, then arm the Beam Permit manually, inform Shift Leader and DCS oncall (by email during the night)
  • peaks on the BCM trends

The injection permits are rearmed automatically after Post Mortem when:

  • ALICE is SAFE and
  • ALICE did not caused the beam dump and
  • LHC injection handshake is in 'injection' phase (the status is ‘LHC injection ready' or 'LHC injection imminent' after the command 'CONFIRM inject' has already been sent from ALICE)
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Topic revision: r1 - 2010-11-26 - MateuszLechman
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