GCALOR studies of background in the LHCb muon chambers

98-059 Here we report on the results of simulation of the background in the LHCb muon system for the layout implemented in the SICB version 114. In particular, the angular and energy distributions of the BG electrons in mu1-mu5 stations are presented. Also, BG fluxes were calculated with variation of some elements of the muon system: with and without quadrupole; for various thickness of the G10 plates simulating the body of the muon detector chambers; for various thickness and outer dimensions of the muon shield; for beam pipe with enlarged aperture in the last muon shield. A recommendation is given to modify the beam pipe inside the last muon shield in order to decrease the background in mu5 and mu4.