Difference between revisions of "BTA guidelines"
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<b>Accelerator beam time</b> | <b>Accelerator beam time</b> | ||
| − | <ul><li>ABU: acceptable beam used</li> | + | <ul><li>ABU: acceptable beam used (eg harp scans, calibrations, trigger settings, running)</li> |
| − | <li>BANU: beam acceptable but not used</li> | + | <li>BANU: beam acceptable but not used (eg radiator change or our problems)</li> |
| − | <li>BNA: beam not acceptable</li></ul> | + | <li>BNA: beam not acceptable (eg tuning, drifting, not focused)</li></ul> |
<b>Experiment beam time</b> | <b>Experiment beam time</b> | ||
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| − | When the BTA information is loaded from epics it contains automatic calculations of accelerator beam time from beamline monitors and 100% UED experiment down. | + | 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. |
<b>Proposed guidelines</b> | <b>Proposed guidelines</b> | ||
| − | 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). | ||
| + | |||
| + | 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 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. | + | 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. | + | Total time should be estimated without spending excessive time on it. Estimating this from myaplot/myaviewer when the beam is unstable is difficult. |
(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.) | (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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<b>Practical hints</b> | <b>Practical hints</b> | ||
| − | The 'load from epics' button is a good starting point but its numbers are | + | 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. | 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 12:18, 6 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 (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)
- 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. We have to change this before saving the timesheet.
Proposed 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.
(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.
