tailieunhanh - Study of multiple photoneutron reactions on 197Au induced by 2.5 GeV bremsstrahlung

We identified eight radionuclides 196Au, 195Au, 194Au, 193Au, 192Au, 191Au, 190Au, 189Au formed via the multiple photoneutron reactions 197Au(γ, kn) 197−kAu with GeV bremsstrahlung. The yields of radionuclides that decay by emitting γ-ray were measured using high purity germanium (HPGe) detector coupled to a PC-based multichannel analyzer. In order to improve the accuracy of the experimental results the necessary corrections were made. The obtained results are compared with reference data and the variations of the 197Au(γ,kn)197−kAu reaction yields according to incident bremsstrahlung energy and neutron multiplicity are also discussed. | Communications in Physics, Vol. 23, No. 4 (2013), pp. 331-338 STUDY OF MULTIPLE PHOTONEUTRON REACTIONS ON INDUCED BY GeV BREMSSTRAHLUNG 197 Au NGUYEN THI HIEN, PHAM DUC KHUE, KIM TIEN THANH, AND NGUYEN VAN DO Institute of Physics, Vietnam Academy of Science and Technology, 10 Dao Tan, Hanoi, Vietnam Received 31 July 2013 Accepted for publication 06 November 2013 Abstract. We identified eight radionuclides 196 Au, 195 Au, 194 Au, 193 Au, 192 Au, 191 Au, 190 Au, Au formed via the multiple photoneutron reactions 197 Au(γ, kn)197−k Au with GeV bremsstrahlung. The yields of radionuclides that decay by emitting γ-ray were measured using high purity germanium (HPGe) detector coupled to a PC-based multichannel analyzer. In order to improve the accuracy of the experimental results the necessary corrections were made. The obtained results are compared with reference data and the variations of the 197 Au(γ,kn)197−k Au reaction yields according to incident bremsstrahlung energy and neutron multiplicity are also discussed. 189 I. INTRODUCTION When high-energy photons pass through matter multiparticle photonuclear reactions are induced. One method of studying these reactions is to measure the yields of the radioactive residual nuclei [1]. The reaction yield is one of the basic data for use in both basic and applied nuclear physics research [2,3]. In practice, the reaction yield is computed from the production rate of a nuclide due to a certain nuclear reaction. Most of the reaction yields reported so far have been measured at low energies [47]. The measurements with high energy projectiles, especially with high energy photons are still very scarce. At low photon energies only simple reactions such as (γ,n), (γ,p) or similar processes are available. These reactions represent only a part of the possible interactions between the photons and complex nuclei. At high photon energies the photonuclear reactions with the emission of multinucleons are the most probable. .