A systematic measurement of energy resolution and e/π ratio of a lead/plastic-scintillator sampling calorimeter

Abstract

The energy resolution and the e/π ratio of a lead/plastic-scintillator sampling calorimeter were measured for various volume ratios of the lead thickness to the scintillator thickness. For this purpose, a hanging-file-type calorimeter module was constructed in which the thicknesses of the lead absorber and the plastic-scintillator plates were able to be altered very flexibly. The thicknesses of the lead and the scintillator plates can be changed by a 2 mm step form 4 to 16 mm and from 2 to 6 mm, respectively. We measured energy resolution for electrons and pions with the calorimeter module as a function of the thickness of a lead plate in the energy range 1–4 GeV. The best energy resolution for pions was obtained to be 33.6%/ E with the configuration where the thicknesses of the lead and the scintillator plates were 4 and 2 mm, respectively. The e/π ratio was measured in the energy range 1–4 GeV. The compensation was found to be achieved for the lead thickness of 9.1±0.3 mm in the case of 2 mm-thick scintillator.