sPHENIX EMCal discussion

[Sean Stoll <stoll AT bnl.gov>]

Here are  a few other questions that occurred to me re the next prototype:

Do we have a firm date for the test?

re: projectivity for the beam test:

Which block shapes do we need to make?

Do we make 4 different shapes ( eg. 24, 23, 22, 21)?

How many of each?  - How many towers are needed in the prototype 8x8? 6x8? more?

Once the shapes are chosen - Do we need to redesign the screens ? Are they different for each shape?

re: emcal electronics:

Are any modifications planned for the EMCal electronics?

    Repositioning warm components to optimize cooling?

    Amplifier design to accommodate 4:1 summing?

    Attachment points for light guides, cooling?

    Shorter boards to fit enclosure?

Additional questions:

How is the EMCal positioned/supported relative to the HCal?

What independent position movement is necessary?

Should we try to use liquid cooling? Or forced air again?

What is the optimal design for light guides?

    Molded to fit 2x8 towers?

    Summed 2x2 towers? (Does this require repositioning sipms on pcb?)

Sean

On 6/30/2016 12:43 PM, John Haggerty wrote:

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.

-- 
Sean Stoll
Physics Associate
Brookhaven Nat. Lab
Upton, NY 11973
631.344.5331