Authors:H. Sakai, A. Uritani, K. Inoue, Y. Takenaka, and C. Mori
We have studied the improvement of energy spectra of a cadmium telluride (CdTe) semiconductor detector by means of a neural network algorithm. The neural network recognized pulse shapes and determined the corrective magnification factors of digitally shaped pulse heights. That is to say, the neural network recognized the difference in the pulse shapes due to the incomplete charge collection and made up for the ballistic deficit of each pulse. We obtained the energy spectra of several gamma ray sources. After the processing, the energy spectra became more ideal profile and the energy resolution (FWHM) changed for the better.
Authors:C. Mori, T. Suzuki, S. Koido, A. Uritani, H. Miyahara, K. Yanagida, Y. Wu, K. Nishizawa, M. Yoshida, F. Takahashi, and J. Miyahara
Distribution images of natural radioactivity in natural materials such as vegetables were obtained by using Imaging Plate. In such cases, it is necessary to reduce background radiation intensity by one order or more. Graded shielding is very important. Especially, the innermost surface of a shielding box should be covered with acrylic resin plate. We obtained natural radioactivity distribution images of vegetables, sea food, meat etc. Mostly -rays emitted from40K print the radioactivity distribution image. Comparison between -ray intensity of KCl solution measured with HPGe detector and that of natural material specimen gave the radioactivity around 0.060.4 Bq/g depending on the kind and the part of specimens.