Difference between revisions of "BTA guidelines"
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=== Guidelines === | === Guidelines === | ||
− | The shift leader should ensure that the accelerator timesheet is consistent with ours. | + | * The shift leader should ensure that the accelerator timesheet is consistent with ours. |
− | + | * First we estimate time spent in UED (hopefully 0) and PCC (configuration changes). Then ER is 60 minutes - (UED+PCC). | |
− | First we estimate time spent in UED (hopefully 0) and PCC (configuration changes). Then ER is 60 minutes - (UED+PCC). | + | * The BNA value loaded from EPICS is usually reliable, so we can use this to calculate ABU = ER - BNA. |
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− | The BNA value loaded from EPICS is usually reliable, so we can use this to calculate ABU = ER - BNA. | + | |
If the beam is unavailable then that is counted as BNA, regardless of whatever we are doing (eg PCC). | If the beam is unavailable then that is counted as BNA, regardless of whatever we are doing (eg PCC). | ||
+ | * BANU should equal the total time when no beam was requested, BANU = 60 minutes - (ABU + BNA). | ||
+ | * 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 myaplot/myaviewer when the beam is unstable is difficult. | ||
+ | * ``If any PCC or UED time is recorded, please write an explanation for this in the Comments field. '' | ||
− | + | * (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.) | |
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− | (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.) | + | |
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− | + | * [https://accwiki.acc.jlab.org/pub/SWDocs/BeamTimeAccounting/Machine_Time_Accounting_User_Guide.pdf Official machine time accounting user guide] | |
− | + | === Practical hints === | |
− | 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. | + | * The 'load from epics' button is a good starting point but its numbers are often incorrect. |
+ | * 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. |
Revision as of 13:46, 9 March 2020
Beam time accounting guidelines (based on Mark D's proposal in Run planning notes, Feb 2)
Accelerator beam time
- ABU: acceptable beam used (eg harp scans, calibrations, trigger settings, running)
- BANU: beam acceptable but not used (eg radiator change or our problems)
- BNA: beam not acceptable (eg tuning, drifting, not focused)
Experiment beam time
- ER: experiment ready
- PCC: planned configuration change (when beam is masked while radiators are moved, etc)</li>
- UED: unplanned experiment down (unpleasant surprises, hardware failure, extended daq issues)</li></ul>
When the BTA information is loaded from epics it contains automatic calculations of accelerator beam time from beamline monitors and 100% UED experiment down. We have to change this before saving the timesheet.
Guidelines
- The shift leader should ensure that the accelerator timesheet is consistent with ours.
- First we estimate time spent in UED (hopefully 0) and PCC (configuration changes). Then ER is 60 minutes - (UED+PCC).
- The BNA value loaded from EPICS is usually reliable, so we can use this to calculate ABU = ER - BNA.
If the beam is unavailable then that is counted as BNA, regardless of whatever we are doing (eg PCC).
- BANU should equal the total time when no beam was requested, BANU = 60 minutes - (ABU + BNA).
- 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 myaplot/myaviewer when the beam is unstable is difficult.
- ``If any PCC or UED time is recorded, please write an explanation for this in the Comments field.
- (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 often incorrect.
- 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.