sPHENIX EMCal discussion

[John Haggerty <haggerty AT bnl.gov>]

You probably saw a very similar post to the HCAL list... the questions 
for the EMCAL are the same, only harder:

Very soon, we need to agree to changes in the "reference design" of the 
calorimeters engendered by the descoping exercise.

In particular, I think the next prototypes we test should be as close to 
the final design as possible.   In the case of the EMCAL, there are some 
real questions that we need to answer very soon:

- Do we even test an eta=1 calorimeter?  No need to test it if we're not 
going to build it.

- Do we test "2x2" towers?  Do we have 4 little light guides with a lot 
of corners, or bigger light guides?  I could imagine a single stuby 
light guide could result in more uniform light collection, but it's not 
at all obvious.

- Do we design preamps that can take 16 SiPM's?  This is a thing that 
Steve would have to test before we did it, and it would have to be moved 
to the front burner if we want it for January.

- Projectivity.  Enough said.

With the substantial changes to the EMCAL we're talking about, we may 
also wish to consider delaying our appointment with the FTBF a month or two.

Since not everyone attends every meeting, I think it's important that we 
discuss this with a wide audience on the lists.  So fire away.

--
John Haggerty
email: haggerty AT bnl.gov
cell: 631 741 3358