Activation cross-sections for short-lived reaction products on hafnium isotopes induced by 1-20 MeV neutrons

Results of new activation cross-section measurements for production of Hf-178m1 (T-1/2 = 4.0 s) and Hf-179m1 (T-1/2 = 18.67 s) are presented for the following reactions: Hf-178(n,n ')Hf-178m1, Hf-179(n,2n)Hf-178m1, Hf-180(n, 3n) Hf-178m1, Hf-179(n,n ')Hf-179m1 and Hf-180(n,2n)Hf-179m1. The irradiations were carried out at the 7-MV Van de Graaff accelerator at EC-JRC, Geel. Neutrons in the 1-3 MeV energy range were produced via the H-3(p,n)He-3 reaction. Deuteron beam and a deuterium gas target were used to produce 5 and 6 MeV neutrons. For the production of quasi-monoenergetic neutrons between 16 and 19.5 MeV the H-3(d,n)He-4 reactions was employed. Both samples with natural composition and isotopic enrichment were employed to differentiate reactions leading to the same product. An automated pneumatic system was used for the sample irradiation, transport and radioactivity measurements. The radioactivity of the samples was determined by standard gamma-spectrometry using HPGe detector. The results obtained in the present work are compared with the data from other authors and TENDL-2017 evaluation.