Geremew, Hailu2018-06-272023-11-092018-06-272023-11-092012-03http://10.90.10.223:4000/handle/123456789/3834In this thesis, the build-up and decay of radioactivity in two stable isotopes of Bromine caused by reaction with slow neutrons will be studied. In particular, we will be able to measure the radioisotope capture cross section of these samples, using HPGe-detector and beta-counter on the decay of radioactivity data taken. For the decay of Br-82 the ground state thermal neutron cross section 0.2565±0.023barn by using High purified Germanium detector and for Br-80 decay the ground state thermal neutron cross section 8.653±0.78barn by using beta counter were observed from this work and the total thermal neutron cross section for the two isotopes obtained from the measurement were compared with the calculated theoretical valuesenThermal NeutronThesis