Neutron-induced activation cross sections on hafnium isotopes from the threshold to 20 MeV

Results of new cross section measurements are presented for the following neutron-induced reactions : ¹⁷⁸Hf(n,α)¹⁷⁵Yb, ¹⁸⁰Hf(n,α)¹⁷⁷Yb, ¹⁷⁷Hf(n,p)¹⁷⁷Lu^g, ¹⁷⁸Hf(n,x)¹⁷⁷Lu^g, ¹⁸⁰Hf(n,p)¹⁸⁰Lu, ¹⁸⁰Hf(n,n'γ)¹⁸⁰Hf^m, ¹⁷⁴Hf(n,2n)¹⁷³Hf, ¹⁷⁶Hf(n,2n)¹⁷⁵Hf, and ¹⁷⁷Hf(n,3n)¹⁷⁵Hf obtained with the activation technique. The irradiations were carried out at the 7-MV Van de Graaff accelerator at IRMM, Geel. Quasi monoenergetic neutrons with energies between 14.8 and 20.5 MeV were produced via the ³H(d,n)⁴He reaction at E_d = 1, 1.4, 2, 3, and 4 MeV. The ³H(p,n)³He reaction was employed for the production of neutrons in the 2 - 3 MeV energy range. Both natural and enriched samples were used to facilitate correction for interference between reactions leading to the same product. The radioactivity of the samples was determined by standard γ-ray spectrometry using HPGe detector. The current measurements are compared with the data from other authors and Evaluated Nuclear Data Files. Cross sections for three of the studied reactions are reported for the first time.