Thermal neutron induced α-particle reaction on64, 65, 67Zn and77Se

The (n th,α) reaction spectroscopy was done on64, 65, 67zn and77Se at the 87 m curved thermal neutron guide of the Grenoble high flux reactor. In each of the64Zn(n, α)61 Ni and67 Ni(n, α) 64Ni reactions, one line showed up corresponding to anα-particle transition to the first excited state in61Ni and64Ni withσ α1=11±3 μb and 159±20 μb respectively. In the case of the radioactive65Zn(T 1/2=244d) nucleus, two lines showed up corresponding to the ground state and the first excited state transitions in62Ni with large values ofσ α0=1.0±0.1b andσ α1=1.0±0.1b. For the77Se(n, α)74Ge reaction, the ground state and first excited transitions were present withσ α0=940±20 μb andσ α1 = 30±5 μb respectively. The spin-parity (J π) of the neutron resonance contributing at thermal energy are discussed.