Electron Detector

Qweak Run 2 preparation

Re-instate the HV connection of the e-detector
QWAD Fan power supply: discontinue using the currently used special PS
characterize all v3 QWADs in Fast Electronics Lab
Set all QWADs to 35% of peak response of 10kel (this number would typically be 37mV)
Machine shop
- get through holes on all the machined QWAD front blocks (idea dropped, suggestions?)
- special screw-driver to reach the QWADs without opening the side cover
- right combination of accessories to attach the QWAD's front blocks to the euro-card-cage.
Threshold voltage PS
- Attached it directly to the same rack as QWAD PS
- Remote access of the power supply successful at port 10 on hctsv5
Connect and verify the motion mechanism cables of the e-detector
Get Ru-106 source in the vacuum-can for radiological source tests
prepare DAQ for data taking (reinstating to the run-1 status)
DAQ tests
- check chip-scope view of the LVDS response
- reason for appearance of 255's
- check for 'missing events' in the overlap region
- vary involved parameter and check responses.
cross-check the cable-labels
update the wiki page
- for emergency response
- for information related to the subsystem

Italics: represents completed General Font: still to be done

from any cdaq machine, from the directory ~/compton/ execute StripTool edetectorEpics.stp . This pulls up the strip chart of some relevant epics variables for e-detector. If we are unable to locate this file, the following epics variables should be explicitly opened.
- 4 Hall-C Chicane BPMs
  - 3P01A (IPM3P01A.XPOS , IPM3PO1A.YPOS)
  - 3P02A (IPM3P02A.XPOS , IPM3PO2A.YPOS)
  - 3P02B (IPM3P02B.XPOS , IPM3PO2B.YPOS)
  - 3P03A (IPM3P03A.XPOS , IPM3PO3A.YPOS)
- Rates on Scintillator (cComptScintRateNorm) on the Compton laser table, along with Photon detector Rates (cComptPhotonRateNorm)
Turn on the HV on the e-detector planes. (Current operating voltage: plane-2: -260V, plane-3: -360V, plane-4: -360V)

Request beam to be set through the chicane, with FFB turned ON

Check Chicane view: on any cdaq machine type edmmonticello, from the Monticello screen
- open Magnets -> Magnet Commander
  - 3C -> Compton Combo
  - In this Hall C Compton Control screen, the REQUESTED and ACTUAL current readbacks should be ~104 A
- open BPM -> BPM Overview
  - open Absolute -> on the Hall C column from the left bottom of this screen
  - BPM 3P01A, 3P02A, 3P02B and 3P03A should have finite non-zero read back
Check compton rates from the photon detector (typically 600 per uA per second)
- If the Scintillator rates are too high (> 2000 Hz/uA), DO NOT proceed without talking to an expert from photon detector group.
- The Fast feedback has been observed to give lower background rate, the status of FFB can be checked on the HALL-C general tools screen on the main-monitor of HALL-C

courtesy: Thanks to Dave Gaskell for the motivation to organize this information