Abstract
The cross correlation method was tried to apply to determine an unknown energy spectrum of γ-rays from observed data using a particular γ-ray detector. This method is as follows: taking the response of the detector for a monochromatic γ-rays as the search spectrum, the cross correlation function between the search spectrum and the data spectrum is computed.
The application of the cross correlation method to the observed results enables to determine the energy spectrum of γ-rays using an organic scintillator. The measurements are performed for γ-rays of radioactive sources with energy over a range from about 0.5 MeV to 1.8 MeV. As compared with the both methods, the response matrix method and that using Fourier transformations, the special merit of this method is that the computing time is very short because the process of computation is simpler than those for the former two methods. For example, the time for processing data obtained by a 400 ch. detector is less than 10 sec by using the FACOM computer model 230-60. The resolving power by this method-the FWHM value of the peak was in the range from -25% to -90% for the change of energy of γ-rays-was poorer than that by using an inorganic scintillator such as NaI (Tl) . However, this problem will be improved with devisery of the shape of the search spectrum and of the process of the computation.
