Fig. 13 shows the mean number of detected photoelectrons
for 3.0 GeV electrons as a
function of the polar angle Theta and the azimuthal angle
Phi.
It shows the angle range where electrons of a given
energy can be detected with good detection efficiency
(e.g. 
)
Detection efficiency is defined here as the ratio of the number of detected particles ( here - electrons ) to the number of particles entering the detector. Inefficiency is the deviation from the unity. Obviously, the particle detection efficiency depends on the applied threshold in terms of number of photo-electrons.
Fig. 14 and Fig. 15 show the electron inefficiencies for different detection thresholds : 1 and 3 photoelectrons respectively. A 3 photoelectron threshold means that the particle is assumed to be detected if there is at least one group of segments where the signal corresponds to 3 or more photoelectrons.
The number of generated events in each cell is
, hence the accuracy of
the simulation
is about
.
Detection inefficiencies are less than
in most of the detected region for a 1 photoelectron
threshold, and less than
in case of a 3 photoelectron threshold
( 
near the middle plane).
Fig. 16 and Fig. 17 show the electron inefficiency for energies of 1.8 and 0.8 GeV, respectively. One can see that the electron detection efficiency is rather independent of the incident electron energy.
