sPHENIX EMCal discussion

[Martin Purschke <purschke AT bnl.gov>]

Dear all,

after close consultation wit Jin (who isn't going to attend the QM) I'd
like to submit the abstract attached below.


I would appreciate it if you would give me your comments, corrections,
and suggestions.


Thanks, best,

        Martin


-- 
Martin L. Purschke, Ph.D.        ;   purschke AT bnl.gov
                                 ;   http://www.phenix.bnl.gov/~purschke
                                 ;
Brookhaven National Laboratory   ;   phone: +1-631-344-5244
Physics Department Bldg 510 C    ;   fax:   +1-631-344-3253
Upton, NY 11973-5000             ;   skype: mpurschke
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Optimizing the Calorimeter design for sPHENIX

Martin L. Purschke, for the PHENIX Collaboration 

The PHENIX collaboration has proposed a major upgrade of the exisiting
experiment at the Relativistic Heavy Ion Collider for the 2020-2022
time frame. The new experiment is built around the former BaBar
magnet, and consists of tracking systems and 3 calorimeters: an
electromagnetic calorimeter based on scintillating fibers embedded in
a tungsten-expoxy matrix, and two steel-scintillator hadronic
calorimeters, one inside the magnetic field, and one outside. The
BaBar magnet has an inner diameter of 280cm and a length of 385cm,
which translates into a pseudorapidity coverage of $|\eta|<1.0$ and a
most extreme angle of incidence of $65^circ$ with respect to a vector
pointing straight to the beam line. Starting from an optimally
projective design with double-tapered EmCal modules, which are
extremely challenging to produce, we present studies of various tilted
calorimeter designs to find the best tradeoff between the uniformity of
the sampling fraction, avoidance of "channeling" paths for particles,
and project costs. We will show the results from simulations
exploring the parameters governing the achievable energy resolutions
and the detector complexity for the three calorimeters.