A calorimeter for detecting hadrons with energies of 10–100 GeV

Abstract

A calorimeter for detecting hadrons in the energy range 10–100 GeV is described. It is used at CERN in the NA58 (COMPASS) experiment aimed at studying the nucleon structure and spectroscopy measurements of charmed particles. The calorimeter is composed of 480 modules with a cross section of 15×15 cm², assembled in a matrix with dimensions of 4.2×3 m² and a central window of area 1.2×0.6 m². In each module are 40 iron and scintillator layers of a total thickness of 4.8 interaction lengths. The energy resolution of the calorimeter for hadrons (pions) and electrons and the spatial resolution, determined on the test beams, are $\frac{{\sigma _\pi (E)}}{{E[GeV]}} = \frac{{59.4 \pm 2.9}}{{\sqrt E }} \oplus (7.6 \pm 0.4)\% ;\frac{{\sigma _e (E)}}{{E[GeV]}} = \frac{{24.6 \pm 0.7}}{{\sqrt E }} \oplus (0.7 \pm 0.4)\%$, and σ _x,y ≈ 15 mm, respectively. The average value of the e/π ratio that characterizes the amplitude responses of the calorimeter to electrons and pions with equal energies from the above range is 1.2 ± 0.1. This study was performed at the JINR Laboratory for Particle Physics.