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    User name brads

    Log entry time 18:24:23 on December 02, 2008

    Entry number 251765

    keyword=BB Cerenkov changes during Controlled Access

    Swapped in fresh C4F8O bottle

    The C4F8O bottle ran out around 10am this morning. I swapped in a new bottle. An empty tank appears to be about 135lbs.

    Shielding modifications

    Added and additional row of 1" thick Pb plates to the beamline side of the witness PMT. That's the shielding limit for this configuration.

    LED pulser can be driven from 2nd floor

    LEDs on PMTs 1, 5, 10 (beamline side) are plugged into the outputs of a linear fan. The input is a cable patched to the 2nd floor counting house on PP #33.

    The trigger for the LED set-up is now T2. Gate timing was confirmed to be good. Several test runs were taken driving the LEDs using a pulser upstairs without beam. We can repeat the test parasitically with beam on to watch for changes (ie. rate-related HV droop, pile-up, etc) in the ADCs.

    LED runs without beam

    These runs are analyzed. ROOTfiles can be found here: '/adaql10/work1/e06010/brad/'
    Tue Dec  2 15:04:55 EST 2008

RHRS-side PMTs turn on only (11 -- 20)
Pulser fanned out to LEDs on PMTs 1, 5, 10 (on beamline side).

HP 8116A pulse generator
  - positive going pulse
  - rate set to 1kHz
  - nominal width set to 10ns on front panel, unless noted
  - front-panel LIL amplitude set to 0.0V
  - nominal front-panel HIL amplitude listed below


Run 4114
- 2.0V amplitude, 15ns FWHM pulse to LED input PP 33 upstairs.
  4.2V setting on pulse generator

Run 4115
- 2.1V amplitude, 15ns FWHM pulse to LED input PP 33 upstairs.
  4.4V setting on pulse generator

Run 4116
- 2.2V amplitude, 15ns FWHM pulse to LED input PP 33 upstairs.
  4.6V setting on pulse generator

Run 4117
- 2.5V amplitude, 20ns FWHM pulse to LED input PP 33 upstairs.
  5.1V setting on pulse generator

Run 4118
- 3.0V amplitude, 20ns FWHM pulse to LED input PP 33 upstairs.
  6.1V setting on pulse generator

Run 4119
- 3.5V amplitude, 20ns FWHM pulse to LED input PP 33 upstairs.
  7.1V setting on pulse generator

Run 4120
- 4.0V amplitude, 20ns FWHM pulse to LED input PP 33 upstairs.
  8.0V HIL setting on pulse generator

Run 4121
- Pulser turned off
- T8 only (ie. pure ped run, no beam, no LED)

Run 4122
- 5.0V amplitude, 25ns FWHM pulse to LED input PP 33 upstairs.
  8.0V HIL setting on pulse generator, 13.5ns width setting

Run 4123
- 6.0V amplitude, 25ns FWHM pulse to LED input PP 33 upstairs.
  8.0V HIL setting on pulse generator, 16.4ns width setting

Run 4124
- 7.0V amplitude, 25ns FWHM pulse to LED input PP 33 upstairs.
  8.0V HIL setting on pulse generator, 22.4ns width setting

Run 4125
- 8.0V amplitude, 35ns FWHM pulse to LED input PP 33 upstairs.
  8.0V HIL setting on pulse generator, 35.4ns width setting

Run 4126
- 8.0V amplitude, 45ns FWHM pulse to LED input PP 33 upstairs.
  8.0V HIL setting on pulse generator, 45.4ns width setting


    A copy of this log entry has been emailed to: meziani