Military-surplus scintillation probes meant for the detection of plutonium contamination are widely available in the surplus market. The DT590A/PDR-56F “Plutonium-239 Contamination X-Ray Probe” was used with the PDR-56 Radiac Set (radiation detection and measurement instrument), that has been obsoleted by the US Air Force.
The probe is designed specifically for detecting the 14 to 21 keV gamma lines emitted by Plutonium-239 along with its main alpha-particle emissions. For this reason, despite its availability in the surplus market, this probe has not found wide acceptance by science enthusiasts interested in radiation counters.
I just posted to www.diyPhysics.com detailed instructions for the construction of my home-built PDR-56-like radiac set capable of driving a surplus DT590A/PDR-56F “Plutonium-239 Contamination X-Ray Probe.” In addition, I also give instructions on how to open the single-channel analyzer window to convert the instrument into a very sensitive, general-purpose gamma radiation counter. Continue reading