Abstract:
The Self-indicating Instant Radiation Dosimeter (SIRAD) is credit card size, self reading, single use dosimeter produced by JP Laboratories. The SIRAD has a chemical strip that changes color based upon incident radiation. The color change is instantaneous and cumulative. The card was designed for first responders as a way for them to have integrating dosimeters without the need for processing facilities. The SIRAD has a range of 0 to 200 rads. Multiple SIRAD cards were exposed to known radiation fields of a gamma source (Cs-137) and two different neutron sources: a PuBe source and the thermal column of the Oregon State University's TRIGA reactor. The chemical strips of each card were compared to the reference dose color key provided with the SIRAD cards. The cards gamma response to Cs-137 was consistent with the manufacturer's claim. The cards did
not show a response to either the fast neutrons of the PuBe source or the thermal neutrons from the reactor. Quantitative measurements of SIRAD response was done using a commercially available document scanner. The scanner was tested to determine the variation in readout across the scannable surface and whether multiple scans would affect the chemical strip. Multiple scanners were examined to determine their consistency in results. The first test showed that the area of scanner utilized would not affect the results. The second test showed that the chemical strip does not change significantly with multiple scans. The third test showed that for accurate comparisons a single scanner must be used.
