sPHENIX HCal discussion

[Edward Kistenev <kistenev AT bnl.gov>]

I am planning to submit enclosed abstract to NSS-MIC (http://2016.nss-mic.org) today. Time permits - please comment, modify, criticize ……

Thanks to everyone

Edward

Feasibility study for improved e/h rejection  in hybrid (EMC/HAD) Calorimeters  with high speed time domain measurements  (Time Expansion Calorimetry)

 

M.Chiu,  E.Kistenev,  A.Sukhanov,   Brookhaven National Laboratory, LI, NY 11973

 

One of the biggest challenges faced by the collider experiments  at the very high collision rates is the identification and extraction of signals related to lepton (e/g )  production in the forward direction. The problem is mainly related to extremely high occupancies  exacerbated  by merged contributions from individual particle showers  and pile-up showers from overlapping collisions to signals observed in individual detector elements.

To overcome these problems, a partial solution is possible in enhanced application of timing domain measurements  to both clustering problems (by  timing matching) and hadron rejection problems (by single tower signal  timing structure classification using mass dependent templates). While timing matching is a relatively well established technique the large scale timing domain signal measurements became feasible only recently with advent of high speed digitization techniques (DRS4 based readout).

The  technical solution to timing domain hadron rejection in the calorimeters proposed in this work is based on the observation that  installing  optical readout on the downstream (particle entrance)  of the calorimeter tower leads to substantial expansion to the total width of the visible signal (from nearly “zero” to twice the light propagation time in the depth direction  of the tower) , a technique which we have called the “Time Expansion Calorimeter”. The time expansion technique as described is likely to perform best if EMC and Hadronic calorimeter compartments are  built mechanically and optically integrated. 

In this work we present the results of the  initial feasibility study of the  single tower TE Calorimeter  (constructed  of   ~18X0 piece cut from pre-existing E864 spaghetti hadron calorimeter and equipped with PMT’s on both ends) in the particle beams at FNAL in the spring of this year and discuss plans for further development along the same path.

 

 

Corresponding author e-mail :   Kistenev AT bnl.gov