Difference between revisions of "BTA guidelines"

Revision as of 19:59, 5 December 2019

Proposed beam time accounting guidelines (based on Mark D's proposal in Run planning notes, Feb 2)

Accelerator beam time

• ABU: acceptable beam used
• BANU: beam acceptable but not used
• BNA: beam not acceptable

Experiment beam time

• ER: experiment ready
• PCC: planned configuration change (when beam is masked while radiators are moved, etc)
• UED: unplanned experiment down (unpleasant surprises, hardware failure, extended daq issues)

When the BTA information is loaded from epics it contains automatic calculations of accelerator beam time from beamline monitors and 100% UED experiment down.

Proposed guidelines

The shift leader should ensure that the accelerator timesheet is consistent with ours. In particular, BANU should equal PCC+UED, the total time when no beam was requested.

During physics running, ABU + BANU should be the duration of good quality beam delivery.

During initial setup following beam restoration the beam quality is not so critical, so beam-time spent checking radiation levels and harp scans etc should be counted as ABU.

Total time should be estimated without spending excessive time on it. Estimating this from myaviewer when the beam is unstable is difficult. Could it be automated?

(The shift leader should also make a log entry at the end of each shift showing the stripcharts for beam current and position following our whiteboard instructions.)

Official machine time accounting user guide

Practical hints

The 'load from epics' button is a good starting point but its numbers are not always correct.

The MCC crew chief shifts end 1h before ours, so they need 'Save info for MCC' to be done as or soon after the 7th hour of our shift ends.