Energy Deposition in my Detector is not Proper

I’m using CdZnTe crystal of dimensions 552.5 mm with quasi-hemispherical gold electrode the radioactive source is 7mm away. I’m using GPS to decay ions. i have attached the snapshots of the simulation for better visualization.


Grey Volume is CdZnTe
Green is the gold electrode

Im also attaching the construction file:

construction.cc (4.4 KB)
construction.hh (1001 Bytes)

the macro for Decay:

/gps/particle ion
#/gps/ene/type Gauss
/gps/ang/type iso
/gps/ion 55 137
/gps/energy 0 MeV

/tracking/verbose 0
/run/beamOn 1000000