The CMOS (Complementary Metal Oxide Semiconductor) image sensor of a smartphone has been known for its sensitivity to gamma-rays. In this research, some smartphones were selected and tested for measurement of gamma-rays emitted from Cesium-137 and Iridium-192 sources. During measurements, the phones were set in video mode while the camera lenses were covered with black adhesive tape to prevent light exposure. Interaction of gamma-rays with the CMOS appeared as flashing bright spots on the image. The bright spots were then counted by using the freely available ImageJ software. Preliminary results indicated that the number of bright spots increased linearly with increase of gamma-ray dose rate. An in-house Android application software was then developed for real-time counting of the bright spots. The application software also allowed users to input a calibration equation so that the phones could simultaneously convert the count rate to display in dose rate. This research demonstrated that, after appropriate calibration, smartphones could be used as gamma-ray measuring devices for radiation safety control involving high activity sources such as in industrial radiography, gamma-ray irradiation facility and medical treatment.
References
[1]
Akaranate, A., Chankow, N. and Pattarasumunt, A. (2013) Fast and Low Cost X-Ray Fluoroscopy Displayed on a 3D Monitor. Open Journal of Applied Sciences, 3, 308-311. http://dx.doi.org/10.4236/ojapps.2013.34039
[2]
Iamsamang, K. and Chankow, N. (2013) Low Cost Gamma-Ray Fluoroscopic System for Se-75 and Ir-192 Industrial Radiography Sources. NDT Spectra (Official Journal of Malaysian Society for Non-Destructive Testing), No. 7, 209- 216.
[3]
Gumiela, M. and Kozik, R. (2012) Studies of the Applicability of CMOS and CCD Sensors for Detection, Dosimetry and Imaging of Alpha, Beta, Gamma, X-Ray and Proton Beam Spots. Studies of the Applicability of CMOS and CCD Sensors for Detection, Dosimetry and Imaging of Alpha, Beta, Gamma, X-Ray and Proton Beam Spots, 2012.
[4]
Cogliati, J.J., Derr, K.W. and Wharton, J. (2014) Using CMOS Sensors in a Cellphone for Gamma Detection and Classification. Using CMOS Sensors in a Cellphone for Gamma Detection and Classification, 26.
[5]
Lederer, C.M., Hollander, J.M. and Perlman, I. (1967) Table of Isotopes. 6 Edition, John Wiley & Sons, New York.
[6]
(1992) International Atomic Energy Agency, Industrial radiography. IAEA, Vienna.
[7]
Studio, A.D. (2008) Aoaophoto Video to Picture Converter 4.0.
[8]
Ferreira, T. and Rasband, W. (2012) ImageJ User Guide: IJ1.46r. http://imagej.nih.gov/ij/docs/guide
