[Moller_intdet] [EXTERNAL] Formation of MOLLER HVMAPS Working Group

[Michael Gericke]

Hello everyone,

As you may be aware, part of the CFI funding for the main detector is 
earmarked for a set of HVMAP detectors that would cover
the ring 5 annulus and the associated electronics. The purpose of these 
detectors is to monitor scattered electron profile at higher
rates than what is meant to be achieved by the tracking GEMs, although 
perhaps not quite at the full beam current (at least not
without integrating the events in the pixels). These pixel detectors are 
meant to be placed close to and probably immediately behind
the the ring 5 quartz tiles. The pixel chips are very thin and will be 
mounted on thin flexprint (chip + flexprint ~100 um) the entire
assembly (with mounting) will probably add less than 2 cm of real-estate 
in the z direction behind the quartz tile, so that the additional
volume will be taken up entirely by the extent of the quartz light guide 
assembly anyway.

Thanks to the ever helpful group of people in Germany, who have 
developed these chips, we (at Manitoba) have been able to gain a fair
bit of familiarity with these detectors and have been working on the 
development of readout PCBs and, more recently, looking at cooling
needs for the chips. But of course, much more work is required to 
achieve the full implementation for MOLLER. Nik Berger's group in Mainz,
is working on using these detectors for actual tracking in the P2 
experiment and has agreed to collaborate on this for MOLLER (for which I
am really grateful). His group is also a main driver of the development 
of these detectors for other experiments, such as Mu3e.

I have also had a brief exchange with Yury about this and he has 
expressed an interest as well and, of course, there is a lot of experience
with these detectors at Berkeley already.

Given the amount of work that still needs to be done, and the somewhat 
special nature of that work, I believe it is high time that we form
a separate working group for this effort (not that anyone needs any more 
meetings). It may be possible to discuss this work in the tracking
meeting, but that may overburden those meetings (I am not sure, I 
haven't been participating in those).

If you have an interest in participating in this work, please let me 
know and please indicate whether you are okay with forming a separate
working group, with separate meeting times, or if this should be 
discussed in the tracking detector meetings.

Thanks,

Michael

-- 
Michael Gericke (Professor, Ph.D.)
University of Manitoba, Physics
213 Allen Bldg.
30 A Sifton Road,
Winnipeg MB, R3T 2N2
Canada