It is vital to minimize the background rates for a given beam intensity.
Possible backgrounds, hadronic and electromagnetic, have been evaluated
using Monte Carlo simulation programs as described in the previous sections.
In the kaon arm, positron background is one of our concerns. In the scattered
electron arm, backgrounds coming from 1) the target area, 2) bremsstrahlung and M
ller electrons
hitting slits and pole faces of the ENGE spectrometer were also evaluated
but should also be examined experimentally.
Those background rates will be studied to establish the acceptable maximum
beam current by changing the targets and beam currents.