Nov 3, 2011 SiPM Electrical and Cooling
From GlueXWiki
Action Items from previous meetings
- Verify location of standoffs for circuit board. (Fernando)
- Location and room for UFL connector for thermistor needs to be finalized. (Chris and Jim)
- Jack to update board with bias compensation circuitry (Jack)
Tentative Agenda
- Announcements
- Action Items
- Schedule, reporting, and manpower (Elton)
- SiPM production testing (everyone)
- Light source / optics
- Electronic boards
- Cabling
- Cooling plate
- Other?
- SiPM testing (Ivan)
- Mechanical assembly (Scot)
- Mechanical (Jim)
- Mechanical drawings (Chuck)
- Temperature compensation (Jack)
- Preamp-summing (Fernando)
Minutes
Attending: Tina Mann, Scot, Carl, Elton, Ivan, Jack, Chuck, Jim, Yi.
- Announcements
- Action Items
- Schedule, reporting, and manpower (Elton)
- SiPM production testing (everyone)
- Light source / optics
- Pulse generator is being refurbished
- 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.
- Cabling
- Cooling plate
- 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.
- Other?
- Light source / optics
- 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.
- 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.
- Mechanical (Jim)
- Milled parts are arriving tomorrow
- Other parts are on order through the JLab machine shop.
- 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.
- 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.
- 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.