Winter 2023 detector checkout + CDC scan

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.