Evaluation of COTS Rad Detection Apps

Wagner, Eric¹ 

[1]National Security Technologies, LLC. (NSTec), Mercury, NV (United States)

关键词: COMPARATIVE EVALUATIONS;    CHARGE-COUPLED DEVICES;    CESIUM 137;    ACCURACY;    CALIBRATION;    CAMERAS;    GAMMA DETECTION;    RADIATION DETECTORS;    RADIOACTIVE MATERIALS;    BENCHMARKS;    PERFORMANCE;    PROGRAMMING;    ERRORS;    RELIABILITY;    SENSORS;    SIGNALS;    TESTING;    MOBILE PHONES;    MICRO SV PER HOUR RANGE;    MILLI SV PER HOUR RANGE;    DATA COVARIANCES;    INFORMATION SYSTEMS;    GROUND TRUTH MEASUREMENTS COTS;    rad detection apps;   

DOI  :  10.2172/1135822
RP-ID  :  DOE/NV/25946--1964
PID  :  OSTI ID: 1135822
Others  :  TRN: US1600003

美国|英语

来源: SciTech Connect

【 摘 要 】

Mobile applications are currently under distribution to smart phones utilizing the built-in charge coupled-device (CCD) camera as a radiation detector. The CCD detector has a very low but measurable gamma interaction cross section so the mechanism is feasible, especially for higher dose rate environments. Given that in a large release of radioactive material these ???crowd sourced??? measurements will be put forth for consideration, a testing and evaluation of the accuracy and uncertainty of the Apps is a critical endeavor. Not only is the accuracy of the reported measurement of concern to the immediate user???s safety, a quantitative uncertainty is required for a government response such as the Federal Radiological Monitoring and Assessment Center (FRMAC) to accept the values for consideration in the determination of regions exceeding protective action guidelines. Already, prompted by the Fukushima nuclear material releases, several repositories of this crowd-sourced data have been created (http://japan.failedrobot.com, http://www.stubbytour.com/nuc/index_en.asp, and http://www.rdtn.org) although the question remains as to the reliability of measurements incorporated into these repositories. In cases of conflict between the real-time published crowd-sourced data and governmental protective actions prepared literature should be on-hand documenting why the difference, if any, exists. Four applications for iOS devices were obtained along with hardware to benchmark their performance. Gamma/X-Ray Detector by Stephan Hotto, Geiger Camera by Senscare, and RadioactivityCounter App by Hotray LTD are all the applications available for distribution within the US that utilize the CCD camera sensor for detection of radiation levels. The CellRad app under development by Idaho National Laboratory for the Android platform was evaluated. In addition, iRad Geiger with the associated hardware accessory was also benchmarked. Radiation fields were generated in a Cs-137 JL Shepherd Model 89 shielded calibration range. The accuracy of the exposure rate within the box calibrator is +/- 5% of the system settings and NIST traceable. This is the same calibration unit utilized for calibration of US DOE exposure rate meters. Measurements were performed from 0.2 to 40,000 mR/hr. Included in the following sections are discussions on each of the evaluated applications and their performance in reporting radiation field measurements. Unfortunately the applications do not provide a readily identifiable quality of the measurement in order to produce error bars or even out of range conditions. In general all the CCD based applications had issues detecting consistent measurements in radiation fields less than 5 mR/hr. This is most likely attributable to the electronic noise level on the CCD???s becoming comparable to the signal level due to the ionizing radiation photons.