Design and Beam Test Results for the sPHENIX Electromagnetic and Hadronic Calorimeter Prototypes

Abstract

sPHENIX is a new experiment with the goal of studying the quark-gluon plasma and further understanding QCD matter and interactions. The sPHENIX detector is currently under construction at the Relativistic Heavy Ion Collider. A prototype of the sPHENIX electromagnetic calorimeter (EMCal) was tested at the Fermilab Test Beam Facility in Spring 2018 as experiment T-1044. The EMCal prototype corresponds to a solid angle of ∆η × ∆φ = 0.2 × 0.2 centered at pseudorapidity η = 1. The prototype consists of scintillating fibers embedded in a mix of tungsten powder and epoxy. The fibers project back approximately to the center of the sPHENIX detector, giving 2D projectivity. The energy response of the EMCal prototype was studied as a function of position and input energy. The energy resolution of the EMCal prototype was obtained after applying a position dependent energy correction and a beam profile correction. Two separate position dependent corrections were considered. The EMCal energy resolution was found to be σ(E)/ E = 3.5(0.1) ⊕ 13.3(0.2)/ √ E based on the hodoscope position dependent correction, and σ(E)/ E = 3.0(0.1) ⊕ 15.4(0.3)/ √ E based on the cluster position dependent correction. These energy resolution results meet the requirements of the sPHENIX physics program.

The sPHENIX experiment at RHIC

“…Equally important is the performance of the calorimeter system. The full calorimeter stack has been tested in several test beam campaigns [3], and the observed performance has been used to confirm the results of GEANT simulations. An example of such simulations is shown in Fig.…”

“…The inner HCAL sits inside a 1.5 T superconducting solenoid, which was obtained from the decommissioned BaBar detector, and has been delivered to BNL and tested at full field in early 2018. Prototypes of the calorimeter system have been successfully tested in test beam data taking periods at FNAL, with the results of the 2016 test described in [3].…”

Silicon photomultipliers in particle and nuclear physics

“…For the sPHENIX experiment at the Relativistic Hadron Collider, two SiPM-based calorimeters are currently being developed [38], a SPACAL -style electromagnetic calorimeter with scintillating fibers embedded in a tungsten powder epoxy matrix, and a steel / scintillator-tile hadron calorimeter with wavelength-shifting fibers embedded in the scintillator plates. For the electromagnetic calorimeter, light guides are used to collect the light of a calorimeter tower on a 2 × 2 matrix of SiPMs.…”

The sPHENIX Experiment

“…Both calorimeter systems were designed to have full azimuth coverage and complement each other in the reconstruction of jets. The performance of the calorimeter prototype has recently been assessed at a testbeam in Fermilab and the results of this study can be found in [3].…”