Deuteron-induced neutron emission on molybdenum at low energies

The high complexity of deuteron-nucleus interactions is due to (i) a variety of reactions induced by nucleons that follow the deuteron breakup (BU), owing to the deuteron weak binding energy, and (ii) the specific stripping and pickup direct reactions (DRs) in addition to the statistical processes of preequilibrium emission (PE) and evaporation from the compound nucleus (CN). Moreover, an update of the limited experimental deuteron database is needed, and there is an incomplete theoretical framework for deuteron activation analysis. Accurate new measurements of low-energy deuteron-induced reaction cross sections for natural Mo target are intended to enhance the related database and provied a consistent account of BU, DR, PE, and CN involved reaction mechanisms. The activation cross sections for <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mmultiscripts><a:mi>Tc</a:mi><a:mprescripts/><a:none/><a:mrow><a:mn>91</a:mn><a:mo>–</a:mo><a:mn>97</a:mn><a:mo>,</a:mo><a:mn>99</a:mn><a:mo>,</a:mo><a:mn>101</a:mn></a:mrow></a:mmultiscripts></a:math> residual nuclei in deuteron-induced reactions on Mo were measured by the stacked-foil technique and high-resolution gamma spectrometry using the U-120M cyclotron of the Center of Accelerators and Nuclear Analytical Methods (CANAM) infrastructure of the Nuclear Physics Institute of the Czech Academy of Sciences (NPI CAS), at energies up to 20 MeV, and using the Neutrons for Science (NFS) SPIRAL2/GANIL facility at energies up to 40 MeV, where a single-foil technique and a dedicated transport system were used for short-lived isotopes. Their extended analysis, including all available data for deuteron interactions with Mo isotopes up to 50 MeV, considered every process from elastic scattering until CN evaporation, with particular attention paid to BU and DR mechanisms. The newly measured activation excitation functions have improved substantially the deuteron database for molybdenum, which is a major constituent of large-scale facilities using deuteron beams. Concurrent analysis of all available data has brought forward questions concerning their consistentcy. The suitable description of nuclear mechanisms involved within deuteron-induced reactions on Mo, especially the BU and DR processes, is validated by overall agreement of the calculated and measured cross sections including the new data at low energies. The analysis of many isomeric-state activation data in this work provides also a quite useful analysis of the CN+PE spin distribution effects.