Sampling Fluctuations in Electromagnetic Calorimeters

The paper presents the results of calculations of the sampling fluctuations in Pb–LAr electromagnetic sandwich calorimeters. The GEANT4 package was used to generate showers initiated by electrons with energies E 0 from 20 to 500 GeV. It is shown that the dependence of the sampling fluctuations on E 0 and the thickness of the lead absorber x can be described by the formula kx b / √(E_0) . The exponent b weakly depends on the LAr gap width d and is close to 2/3 and k = 0.1985−0.0363ln d [mm].