The intrinsic detection efficiency of a detector channel
is the ratio between the number of particles counted in that channel
to the number of particles that have crossed the detector aperture.
It depends on the particle type, energy and incidence angle. Figure
1 shows the angle averaged intrinsic detection efficiency of the
CPD channel P11 for electrons (red), protons (green) and alpha -
The particle flux is considered isotropic. The efficiency function
contains all the information about the characteristics of particles
counted in a given channel. Such
functions have been calculated using
the particle transport code GEANT for all the 44 CPD channels and
for the three targeted particle species. Details on the use of efficiencies
to deduce fluxes may be found in Section 3.1 of Technical
Note B (pdf file - 1 Mb).