Preequilibrium Emission of Light Fragments in Spallation Reactions

TL;DR

This paper enhances nuclear reaction models to better predict high-energy light fragment emissions during the precompound stage, improving agreement with experimental data for reactions involving heavy ions and protons.

Contribution

The work introduces a generalized precompound model that accounts for emission of light fragments larger than 4He, increasing the predictive accuracy of existing event generators.

Findings

Improved agreement with experimental LF spectra data.

Enhanced model capability for high-energy LF emission.

Better prediction of light fragment production in spallation reactions.

Abstract

The ability to describe production of light fragments (LF) is important for many applications, such as cosmic-ray-induced single event upsets (SEUs), radiation protection, and cancer therapy with proton and heavy-ion beams. The Cascade-Exciton Model (CEM) and the Los Alamos version of the Quark-Gluon String Model (LAQGSM) event generators in the LANL transport code MCNP6, describe quite well the spectra of fragments with sizes up to 4He across a broad range of target masses and incident energies (up to ~ 5 GeV for CEM and up to ~ 1 TeV/A for LAQGSM). However, they do not predict the high-energy tails of LF spectra heavier than 4He well. Most LF with energies above several tens of MeV are emitted during the precompound stage of a reaction. The current versions of our event generators do not account for precompound emission of LF larger than 4He. The aim of our work is to generalize the precompound model to include such processes, leading to increased predictive power of LF production. Extending the model in this way provides preliminary results that have much better agreement with experimental data.