Nov 3, 2011 SiPM Electrical and Cooling

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Action Items from previous meetings

  1. Verify location of standoffs for circuit board. (Fernando)
  2. Location and room for UFL connector for thermistor needs to be finalized. (Chris and Jim)
  3. Jack to update board with bias compensation circuitry (Jack)

Tentative Agenda

  1. Announcements
  2. Action Items
  3. Schedule, reporting, and manpower (Elton)
  4. SiPM production testing (everyone)
    1. Light source / optics
    2. Electronic boards
    3. Cabling
    4. Cooling plate
    5. Other?
  5. SiPM testing (Ivan)
  6. Mechanical assembly (Scot)
  7. Mechanical (Jim)
  8. Mechanical drawings (Chuck)
  9. Temperature compensation (Jack)
  10. Preamp-summing (Fernando)

Minutes

Attending: Tina Mann, Scot, Carl, Elton, Ivan, Jack, Chuck, Jim, Yi.

  1. Announcements
  2. Action Items
  3. Schedule, reporting, and manpower (Elton)
  4. SiPM production testing (everyone)
    1. Light source / optics
      • Pulse generator is being refurbished
    2. Electronic boards
      • New CAEN V792 boards have arrived. Yi checked their operation. We now have 7 QDCs.
      • Old CAEN V792 boards have been returned for modification of the middle connector.
    3. Cabling
    4. Cooling plate
    5. Programming
      • Yi has setup a data base for storing test information. There are instructions on how to access the data at Test Results.
      • Yi and Elliott are setting up an ELog that will be used for the SiPM testing station. He will send out a link and information when it is live.
    6. Other?
  5. SiPM testing (Ivan)
    • Ivan showed Oscilloscope data for the 25 and 50 micron SiPMs measuring the dead time per pulse of tau=8 and 18 ns respectively. This is consistent with Hamamatsu data sheets.
    • The rate dependence was also measured and shows pulse reduction of about 20% and 50% respectively for the 25 and 50 micron SiPMs at 10^7 Hz. This effect needs further study, but may show that continuous operation at high rates affects the sensor performance.
    • The DAQ is now operational, which will allow more detailed tests to be conducted.
    • Carl has a photodiode that he can lend Ivan to check linearity of light source
    • The picosecond laser from Hamamatsu is expected toward the end of the month.
    • Yi suggested that Ivan measure the current draw as a function of rate, which might help to understand the rate behavior.
  6. Mechanical assembly (Scot)
    • Checked operation of chiller and it works fine.
    • Received two RTDs to be placed one on the input and the other on the output tubes.
    • The RTDs will need a controller. Scot will see if Hall D has an existing one that can be used; otherwise one will be ordered.
    • Tina is evaluating the optimal amounts of glue to use. Has a calibrated dispenser which will be used to allocate proper amounts of glue for each guide.
  7. Mechanical (Jim)
    • Milled parts are arriving tomorrow
    • Other parts are on order through the JLab machine shop.
  8. Mechanical drawings (Chuck)
    • The specification on the light guide will be relaxed to specify the haze < 2% (from 1%).
    • Drawings of the readout sizes will be made to provide to collaborators (Regina and Athens), which need the information for interfacing with the calorimeter module.
  9. Temperature compensation (Jack)
    • Jack has checked the data from the latest batch of 120 sensors from Hamamatsu. They seem to include outliers relative to the previous samples.
  10. Preamp-summing (Fernando and Chris absent)
    • Boards for SiPM testing are being checked by Fernando.
    • Boards for production setup are awaiting updates on the bias compensation board by Jack.