FPS/FPOST SiPM Study

This page will contain necessary information for the SiPM (Silicion Photomultiplier) radiation damage study.

The goal of this study is to see if we can understand and reduce the effects of neutron radiation damage on SiPMs by accurately measuring their breakdown voltage and using that as a way to explain and adjust the working parameters of the SiPM.

In the proposal you can find some more details as well as this list.
I also attached some slides regarding the inner workings of the SiPMs and why this study is being conducted in this way.
Here is a link to the Hamamatsu Website where you can find more information on SiPMs (Found in the slides as well).
https://www.hamamatsu.com/us/en/community/optical_sensors/articles/technical_guide_to_silicon_photomultipliers_sipm/index.html

Below is a summary of things to do in the upcoming months
I will try to highlight or mark things as we complete them.

Summary of things to do before Run 18:

  1. Start by constructing a black box and set up a test bench to do an IV scan of unused FPS SiPM for a scan range of 62V to 72V using steps of 0.02V
  2. Find its breakdown voltage using this scan and compare to manufacturer.  If everything is good move on to 3 (If not give up :)
  3. Repeat Scan for unused and used FPOST SiPM
  4. Find its breakdown voltage
  5. Change scan parameters to see what is minimum requirements to get a reasonable breakdown voltage for a used and unused SiPM
  6. Design and build new FEE board to have such scan parameters (Only a 4 or 5 should do)
  7. Replace FEE boards for a few channels on FPOST with these new boards as well as a couple of SiPMs with new ones
  8. Run an IV scan with these new boards
  9. Run a pedestal scan with new boards
  10. Change bias voltage setting based on data from the IV scan (Bias should be ~+3V above breakdown voltage) and see if it affects pedestals

Summary of things to do during Run 18:

  1. Take monthly or bimonthly pedestals (This also depends on item 10 above)
  2. Take monthly or bimonthly IV scans
  3. (Optional and depends on 10 above) Take some data during beam dumps if possible