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arXiv · 1610.00627

A non-equilibrium microscopic description of spallation

P. Napolitani·M. Colonna
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Abstract

We investigate the prompt emission of few intermediate-mass fragments in spallation reactions induced by protons and deuterons in the 1 GeV range. Such emission has a minor contribution to the total reaction cross section, but it may overcome evaporation and fission channels in the formation of light nuclides. The role of mean-field dynamics and phase-space fluctuations in these reactions is investigated through the Boltzmann-Langevin transport equation. We found that a process of frustrated fragmentation and re-aggregation is a prominent mechanism of production of IMFs which can not be assimilated to the statistical decay of a compound nucleus. Very interestingly, this process may yield a small number of IMF in the exit channel, which may even reduce to two, and be wrongly confused with ordinary asymmetric fission. This interpretation, inspired by nuclear-spallation experiments, can be generalised to heavy-ion collisions approaching the fragmentation threshold.

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P. Napolitani, M. Colonna. 2016-10-03. A non-equilibrium microscopic description of spallation. https://doi.org/10.1393/ncc%2Fi2016-16384-8

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