A system and associated method for isolating intended radiation signals for determining target characteristics includes multiple detectors for detecting radiation signals having varying energies, delay modules for delaying the detected radiation signals and a discriminator associated with the multiple detectors for determining if detected radiation signals include unintended radiation signals, e.g., x-rays, and provided blanking signals to a switch in order to effectively remove the unintended radiation signals from the data that is presented to the processor for determining target characteristics.