A MEASUREMENT OF THE 93Nb(n,n')93mNb CROSS-SECTION IN THE ENERGY RANGE 1 TO 6 MeV
Harwell Laboratory, Oxon., UK
Michael F. Murphy and William H. Taylor
Atomic Energy Establishment Winfrith, Dorset, UK
Chemistry Department, Birmingham University, UK
The 30 keV isomer production cross-section in 93Nb excited by neutron inelastic scattering has been measured at ten neutron energies. Small foils of niobium were exposed to high fluences of "monoenergetic" neutrons and the cross-section was determined from the induced K x-ray activities. The detector used in the activation measurements was calibrated with a standard solution of 93mNb which is used as an international reference material for reactor neutron dosimetry. The neutron fluence of the irradiation was measured with a low efficiency 235U fission chamber in which the fissile deposit is located immediately behind the niobium foil. The 93mNb production cross-section is thus determined relative to the 235U(n,f) standard reference cross-section.
KEYWORDS: 93Nb, 30 keV isomer, differential cross-section, activation, fission monitor