Difference between revisions of "Electron Detector"

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* ''Re-instate the HV connection of the e-detector''
 
* ''Re-instate the HV connection of the e-detector''
 
* ''QWAD Fan power supply: discontinue using the currently used special PS''
 
* ''QWAD Fan power supply: discontinue using the currently used special PS''
* [http://hallcweb.jlab.org/polwiki/index.php/Image:MeanResponseQWADv3.png characterize all v3 QWADs in Fast Electronics Lab]
+
* [http://hallcweb.jlab.org/polwiki/images/0/08/MeanResponseQWADv3.pdf characterize all v3 QWADs in Fast Electronics Lab]
 
* Set all QWADs to 35% of peak response of 10kel (this number would typically be 37mV) (Sunday, Sept 23, 2011)
 
* Set all QWADs to 35% of peak response of 10kel (this number would typically be 37mV) (Sunday, Sept 23, 2011)
 
* ''Machine shop''  
 
* ''Machine shop''  

Revision as of 10:25, 28 September 2011

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) (Sunday, Sept 23, 2011)
  • 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
    • Attach it directly to the same rack as QWAD PS
    • Remote access of the power supply (successfully connected from a laptop)
  • 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
  • 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

Standard Running Procedure

  • 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

Backout Procedure

https://hallcweb.jlab.org/polwiki/index.php/E-Detector_Motion_System#Parking_the_detector




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

Diamond strip electron detector

Test Box

Shielded Flex Cables

Q-Weak Amplifier Discriminator

Low Voltage Power supply for QWAD

e-Detector Motion System

e-Detector Assembly

e-Detector High Voltage