sPHENIX discussion of electronics

[Gabor David <david AT bnl.gov>]

        A few remarks/reminders to yesterday's discussion on the
current SiPM tester and large-scale SiPM tests.

        Mike asked how come one SiPM takes O(30min) but 169
"isn't much longer"?  The main issue is the settling time
of the HV supply, see Balazs' slide 9 in (Feb 27, 2017)

https://indico.bnl.gov/conferenceDisplay.py?confId=2890

        A very flexible (but small, 2x2 SiPM's) testing device
will come to and remain at BNL early May.  Balazs will be here
and available for ~ one week to show how it can be used.

        Eric pointed out that we need to "develop a viable
test/sorting plan and schedule", which is defensible and
indicates required resources.  This is pretty hard to do
with the CD-1 deadlines (directors review Aug 7 ???) and
almost all necessary information coming AFTER that
(tests of 1800 SiPM's won't even start until September).
Obviously any advance info would be helpful, even if
rudimentary or not 100% reliable.  For instance
        - it would be important to know in what form will
the company doing the final board assembly take the SiPM-s?
On trays like the ones Hamamatsu is delivering on?  Some tape?
Or what? (This might even influence the design of the trays
of the large scale testing device!)
        - does Hamamatsu's promise to test 3% mean random
3% or 3% on every 13x13 delivery tray?
        - is it true (what Craig assumed yesterday) that
each 13x13 tray will have SiPM's from the same production
wafer?
        - etc.

        I'm aware that you might now have all (or even any!)
of those answers - just wanted to point out that any, even
approximate advance info would help us (Debrecen) a lot.

        Thanks,

        Gabor



--
Gabor David  (david AT bnl.gov)
Stony Brook University
[Brookhaven National Laboratory
Physics Department, Bldg 510/c
UPTON NY 11973
Tel: (631)344-3016
FAX: (631)344-3253]