Sep 29, 2011 SiPM Electrical and Cooling

Action Items from previous meetings

1. Carl to check instability of LED (as a possible contributor to sensor output changes) (Carl)
2. Jack and Carl to review data sheets from Hamamatsu. Pick a couple of outlying samples for testing and checking against specs.
3. Chris to check HV specs on coax cable. (Needs to hold at least 80 V).

Tentative Agenda

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

Minutes

Attending:

1. Announcements
2. Action Items
3. Schedule, reporting, and manpower (Elton)
   • Updated evms sheets
4. SiPM testing (everyone)
   1. Light source / optics
   2. Electronic boards
      • The two adaptor boards are done. Fernando should check next week so they can be ordered
      • The Preamp boards has some issues related to the holes on the boards. Jack needs to concur with possible locations. Some difficulties duplicating circuitry, but Chris thinks he has a work-around. They should be ready next week.
      • Two CAEN modules are incompatible with the VME backplane, but can be modified to fit according to CAEN. Carl will try to have the information sent so that we can make the modification here.
   3. Cabling
      • Cables in hand
   4. Cooling plate
      • Drawing is made and machine shop is looking into who can do it and pricing
   5. Production
      • Jack and Carl have looked at the stats from Hamamatsu and they all look good. Some outliers have DR up to 26 MHz, still much below our specification.
      • Jack has looked at the bias information from Hamamatsu and sees a consistent picture compared to the first article units. The chip bias varies smoothly across the wafer. It appears Hamamatsu has selected all chips above a minimum bias and let the bias tail extend up to higher voltages, but still within the range provided by the first articles.
      • Elton will go ahead and approve payment for the first batch.
   6. Other
      • Carl mentioned that a new company is interested in getting into the SiPM business (Amplification Technologies, out of Brooklyn?). They are trying to arrange a visit to JLab, possibly next week. Carl will send out a message with specifics.
5. Mechanical (Jim)
6. Mechanical drawings (Chuck)
7. Guides (Scot)
   • Ordered some UV curing glues and pieces of acrylic for testing.
   • Also investigating laminating material that can be used for wrapping the light guides.
8. Temperature compensation (Jack)
   • Getting ready for the bias and temperature compensation review on Oct 13. Has sent out a preliminary agenda. (Note: I have placed it on the preliminary agenda for that meeting day.)
9. Preamp-summing (Fernando)
10. Granularity (Elton)