Technique for measuring radiation flux density and flux density spectrum

The invention is related to nuclear physics area and can be used for measuring in an inhomogeneous scattering medium the flux density spectrum (and, of course, flux density value) of any radiation which mirror reflection from a flat surface can be obtained and, in particular, in radiation physics and dosimetry areas for measuring the flux density spectrum of electron and beta radiation. The method suggested, for example, permits to measure the beta radiation flux density spectrum in the energy range of 10 keV-10 MeV in light atomic media at an error of 10% and at lower accuracy in media with large charge of nucleus. To test efficiency of the method and the whole device for its realization as a whole measured was the flux density spectrum at the boundary of Sr90 + Y90 semiinfinite homogeneous source