  The beam calorimeter, located in the very forward and backward region of the
next generation electron-positron linear accelerator, will be an important
apparatus to search for or identify new particles beyond Standard Model. One of
its key design issues is to estimate the radiation dosage due to beam related
backgrounds. We used the geant-based package, Jupiter, for the proposed GLD
detector in this study. The dosage received per year for the inner most ring
will be around 10 Mrad. An algorithm for electron identification with beam
calorimeter under nominal background condition is developed and is used for the
feasibility study of smuon search. The result is satisfactory.
