Evaluation of performance characteristics of portal monitor for radiation emergency.

For evaluating the counting efficiency of a portal monitor, we use a137Cs radiation point source (1 μCi) to subsequently establish it effective measurable area. Through simulation, we estimate the appropriate distance from potentially contaminated individuals in the scanning queue to the monitoring individual. When this distance is over 10 m, the counting efficiency was below 0.01%. We find that the triage can be applied to roughly 180 individuals per hour during mass casualties.