GAMMA-RAY PRODUCTION CROSS SECTIONS OF SOME STRUCTURAL AND SHIELDING MATERIALSJapan Atomic Energy Research Institute Tokai-mura, Ibaraki-ken, Japan Masayuki IGASHIRA, Toshiro UCHIYAMA, Hideo KITAZAWA Tokyo Institute of Technology O-okayama, Tokyo, Japan Manfred DROSG University of Wien, Wien, Austria Gamma-ray production cross sections have been measured for structural and shielding materials such as Al, Si, Fe, Pb and Bi at a neutron incident energy of 7.8 MeV. Neutrons were produced by the 2H(d,n)3He reaction at the JAERI Tandem Accelerator. Emitted gamma-rays were measured with a 7.6 cm diameter × 15 cm long NaI(Tl) detector surrounded by an 25.4 cm diameter × 25.4 cm long annular NaI(Tl) detector. The time-of-flight technique was used to eliminate the background caused by the scattered neutrons. In addition to corrections for neutron multiple scattering and gamma-ray self-shielding, special attention was paid to make an accurate correction for gamma-rays emitted due to Compton scattering in the samples. This effect appears to increase the observed low energy parts of the gamma-ray spectra by as much as 40 % in our samples. The measured results were compared with existing data and with the new evaluated data JENDL-3T based on the multi-step Hauser Feshbach calculation. KEYWORDS: Gamma-Rays production cross sections, Al, Si, Fe, Pb, Bi, En = 7.8 MeV, Tandem, NaI, Anti-Compton detector, Unfolding |