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

The energy resolution and the e/pi ratio of a lead/plastic-scintillator sam pling calorimeter were measured for various volume ratios of the lead thick ness to the scintillator thickness. For this purpose, a hanging-file-type c alorimeter module was constructed in which the thicknesses of the lead abso rber and the plastic-scintillator plates were able to be altered very flexi bly. 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 measur ed 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. T he best energy resolution for pions was obtained to be 33.6%/root E with th e cofiguration where the thicknesses of the lead and the scintillator plate s were 4 and 2 mm, respectively. The e/pi ratio was measured in the energy range 1-4 GeV. The compensation was found to be achieved for the lead thick ness of 9.1 +/- 0.3 mm in the case of 2 mm-thick scintillator. (C) 1999 Els evier Science B.V. All rights reserved.