Measurement of (n,2n) Cross-sections for Sc, Mn, Cr and In between 12 and 19 MeV with activation technique

摘要

Activation cross-sections for scandium, manganese, chromium and indium have been measured in the neutron energies from 12 to 19 MeV. Source neutrons were produced via the T(d,n)4He reaction by bombarding a 3.2-MeV deuteron beam from the Dynamitron accelerator of Fast Neutron Laboratory at Tohoku University. Ten packages of high or ultra-high purity metal foils for chromium and indium, alloy foils for manganese, and oxide powder for scandium were set around the neutron source at 5 cm from the target in the angular range from 0 to 140 deg covering the incident neutron energies from 19 to 12 MeV at the center position of each package. Activation rates of the samples were obtained by the gamma-ray measurements using a high purity germanium detector. Neutron flux at each sample was determined using the activation rates of two niobium foils locating both sides of that sample; the reference reaction was ~(93)Nb(n,2n)~(92)mNb of which cross-section data was taken from the 1991 NEANDC/INDC standard files. The source neutrons distributions have been measured in detail by the time-of-flight technique. The measured cross-sections are the following important dosimetry or activation reactions: ~(45)Sc(n,2n)~(44m)Sc, ~(55)Mn(n,2n)~(54)Mn, ~(52)Cr(n,2n)5iCr, and ~(115)In(n,2n)~(114)mln. These cross-sections are compared with available activation file, dosimetry files and previous experimental data.