  Radiation-hard ionization chambers were tested using an intense electron beam
from the accelerator test facility (ATF) at the Brookhaven National Laboratory
(BNL). The detectors were designed to be used as the basic element for
monitoring muons in the Main Injector Neutrino beamline (NuMI) at the Fermi
National Accelerator Laboratory (FNAL). Measurements of linearity of response,
voltage dependence, and the onset of ionization saturation as a function of gap
voltage were performed.
