Difference between revisions of "Winter 2023 detector checkout + CDC scan"
(→Short CDC HV scan) |
(→Short CDC HV scan) |
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Please collect 9M triggers at the following HV settings (in V) for ALL CDC, in the order given below. | Please collect 9M triggers at the following HV settings (in V) for ALL CDC, in the order given below. | ||
| − | In the logbook, please note the run number, HV and the pressure (EPICS variable RESET:i:GasPanelBarPress1, listed in RCDB as cdc_gas_pressure) at the start of each run. | + | In the logbook (HDCDC & HDLOG), please note the run number, HV and the pressure (EPICS variable RESET:i:GasPanelBarPress1, listed in RCDB as cdc_gas_pressure) at the start of each run. |
*2150 | *2150 | ||
| Line 17: | Line 17: | ||
*2100 | *2100 | ||
| + | <!-- | ||
During the 2125V run, when the beam current is steady, run the script below as hdops on one of the gluons. This will save some EPICS values that the CDC's AI will use later on. | During the 2125V run, when the beam current is steady, run the script below as hdops on one of the gluons. This will save some EPICS values that the CDC's AI will use later on. | ||
<pre> | <pre> | ||
| − | /group/halld/AIEC/utilities/CDC_control_ai/ | + | /group/halld/AIEC/utilities/CDC_control_ai/primex/AIEC_CDC.py -c /group/halld/AIEC/utilities/CDC_control_ai/primex/AIEC_CDC.cfg -I 15 |
</pre> | </pre> | ||
The (rather lengthy) output messages should end with ‘Writing new config file...’. If there are any problems with the script, send Thomas an email, tbritton@jlab.org | The (rather lengthy) output messages should end with ‘Writing new config file...’. If there are any problems with the script, send Thomas an email, tbritton@jlab.org | ||
| − | + | --> | |
If the pressure is changing by 0.05+ kPa between measurements, give up. We can try again after the empty target run. | If the pressure is changing by 0.05+ kPa between measurements, give up. We can try again after the empty target run. | ||
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Set the HV back to 2125V after the scan. | Set the HV back to 2125V after the scan. | ||
| − | If the beam is steady then the whole procedure should take a few hours at most. If there are any problems, please | + | If the beam is steady then the whole procedure should take a few hours at most. If there are any problems, please send an email to the CDC experts and RC (Beni and Lubomir and Naomi and Alexandre) to reschedule the scan. |
==How to set the CDC HV and switch AI on/off== | ==How to set the CDC HV and switch AI on/off== | ||
Latest revision as of 05:56, 11 January 2023
General detector calibration
- Use 4.5×10-4 Al. radiator (on goni). Beam current 150nA. GlueX trigger. CDC at its default 2125V with the AI OFF (see below).
- Run 15 min (solid time) in Long Mode (Mode 10)
- Run 15 min (solid time) in Production Mode (Mode 9).
Short CDC HV scan
- Use 4.5×10-4 Al. radiator (on goni). Beam current 350nA. GlueX trigger. CDC's HV AI switched OFF (see below).
Please collect 9M triggers at the following HV settings (in V) for ALL CDC, in the order given below. In the logbook (HDCDC & HDLOG), please note the run number, HV and the pressure (EPICS variable RESET:i:GasPanelBarPress1, listed in RCDB as cdc_gas_pressure) at the start of each run.
- 2150
- 2125 (also see below)
- 2100
If the pressure is changing by 0.05+ kPa between measurements, give up. We can try again after the empty target run.
Set the HV back to 2125V after the scan.
If the beam is steady then the whole procedure should take a few hours at most. If there are any problems, please send an email to the CDC experts and RC (Beni and Lubomir and Naomi and Alexandre) to reschedule the scan.
How to set the CDC HV and switch AI on/off
Find the main action bar (vertical menu), click CDC voltages.
In the middle of the circle on the left, click ALL HV, then select from the dropdown menu "CDC: Set CDC HV parameters". Change voltage to what you want in the left column, hit return.
The AI is switched on/off using the button in the top middle of the CDC's HV GUI. It should only be toggled at the request of the detector expert or RC. When the AI is on, the CDC HV might be changed when the DAQ starts a run. When the AI is switched off the HV is unchanged - it does NOT set the HV back to the default 2125 automatically.
