ATTENUATION OF ATOMIC-FIELD BREMSSTRAHLUNG FROM TL-204 AND TC-99 IN ATHICK TARGET

Attenuation of the atomic-field bremsstrahlung, which is known as the external bremsstrahlung (EB), excited by Tl-204 and Tc-99 beta-emitter s in Al, Cu, Cd and Pb targets has been studied. The beta stopper tech nique is employed to measure the integral intensities above 100 keV en ergy in different absorber thicknesses. The calculated values were obt ained from the bremsstrahlung spectra recorded with different targets and the tabulated values of attenuation coefficients for mono-energeti c gamma rays. A good agreement between the calculated and experimental results is obtained. It supports the correctness of the procedure use d to obtain the attenuation of EB in metallic targets.