A radiation detection device, system, and method for use in homeland
security is disclosed. The device is portable and includes a
photomultiplier tube (PMT) connected to an end of a substantially rigid
thin-walled aluminum tube. Inside the aluminum tube, a substantially
straight scintillating fiber is disposed (so as to be shielded from
ambient light), and an end of the scintillating fiber is optically
coupled to the PMT. A voltage output signal from the PMT is
signal-processed with a filter to remove high-frequency noise (which may
arise from solar radiation spikes) and fed to a voltage-responsive alarm
or signalling device. The portable device is employed, for example, in
baggage and vehicle radiation scanning systems, as well as for large-area
radiation mapping and directional radiation sensing.