| How to perform a wire scanning of the electron detector ? |
Wire Scanning.
The aim of this procedure is to be able to determine
the absolute location of the strips with respect to
the beam in order to calibrate the system. This is performed by
moving some wires in the beam and recording the position of the
wires and the rates produced in some counters downstream.
When you perform this procedure, the beam must be going
through the chicane. For this procedure only you can have beam ON while moving the detector.
Not following this procedure will eventually destroy the detectors.
- Print this procedure and check each point after you have done it.
- Make sure that the beam is going through the chicane.
- Ask the run coordinator for his permission to do
the wirescan which should take about 5 minutes and warn the hall A shift.
- Open the Electron Detector Epics screen.
- Ask MCC for 5 mA
of beam current (and ask them to mask FSD-electron (not implemented yet)).
- Select speed of motion in the EPICS screen, although a speed of 3 is fine.
- When you have 5 mA.
Start a run using the run type "scanacq".
- After 15 seconds, move the wires by clicking on either the "garage" or "beam" button
depending on where the detector was and make sure that the detector is moving by looking at the TV screen.
- If the beam trips during the wire scan use 2 mA instead of 5 mA.
and start a new run.
- Make one round trip, wait 15 seconds between the two legs (the software works better like this).
- Stop your run.
- Put the electron detector in the position you want (IN or OUT)
- (Ask MCC to unmask FSD-electron (not implemented yet))
- Tell the hall A shift that you're done.
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