Deuteron-induced reaction mechanisms at low energies

Abstract

Abstract. An extended analysis of the reaction mechanisms involved within deuteron interaction with nuclei is presented. An increased attention is devoted to the breakup mechanism, all its components, namely the elastic, inelastic (fusion), and total breakup being carefully considered. Next, the direct reactions represented by the stripping and pick-up mechanisms are discussed. Finally, the pre-equilibrium and compound-nucleus contributions, corrected for the breakup, stripping, and pick-up decrease of the total reaction cross section, complete the deuteron-induced reaction cross section analysis. The overall agreement between the measured data and model calculations validates the description of nuclear mechanisms taken into account for the deuteron-nucleus interaction.

On reaction mechanisms involved in the deuteron–induced surrogate reactions

“…On the other hand, the BF component, where one of the deuteron constituents interacts with the target nucleus, leading to a secondary composite nucleus, brings contributions to different reaction channels [5,6,7,8]. Thus, the absorbed proton or neutron following the deuteron breakup contributes to the enhancement of the corresponding (d, xn) or (d, xp) reaction cross sections, respectively.…”

“…In order to calculate the BF enhancement of, e.g., the (d, xn) reaction cross sections, the BF proton-emission cross section σ p BF should be multiplied by the ratios σ (p,x) /σ p R , corresponding to the above-mentioned enhancing reaction, convoluted with the Gaussian line shape distribution of the breakup proton energy E p for a given deuteron incident energy E. Finally, the integration over the breakup proton energy provides the BF enhancement cross section [6,7,8]:…”

“…Interpolated values of the experimental nucleon-induced reaction cross sections from EXFOR library [12] have been involved within the BF enhancement estimation, e.g., Refs. [6,7,8], in order to reduce as much as possible the supplementary uncertainties brought by additional theoretical calculations. The BF enhancements brought by breakup protons and neutrons emitted during the deuteron interaction with 27 Al, 63 Cu, 64 Ni, 93 Nb, and 231 Pa through the (n, p), (n, α), (p, n), and (p, 2n) reactions populating various residual nuclei, are shown in Fig.…”

“…However, only the surrogate ratio method was shown to be valid in the presence of the deuteron breakup without assuming specific breakup mechanism [2,3], while the surrogate absolute method should be applied with caution, and supplementary, "it seems to be hopeless to apply it for the capture cross-section measurements" [2]. The significant larger uncertainty characterizing the (d, x) surrogate reactions is the result of the high complexity of the deuteron interaction process, due to its breakup (BU) mechanism followed even at low bombarding energies by a variety of reactions induced by the deuteron-breakup nucleons [5,6,7,8].…”

“…(d, p) and (d, n) stripping as well as the (d,t) and (d, α) pick-up reactions contributions to the population of a certain residual nucleus have been shown to be important at low incident energies [5,6,7]. Thus, the present work concerns a deeper analysis of the key role of every direct interaction, i.e., breakup, stripping and pick-up processes, for the deuteron-induced surrogate reactions.…”