title: Assessment and requirements of nuclear reaction databases for GCR transport in the atmosphere and structures.
abstract: The transport properties of galactic cosmic rays (GCR) in the atmosphere, material structures, and human body (self-shielding) are of interest in risk assessment for supersonic and subsonic aircraft and for space travel in low-Earth orbit and on interplanetary missions. Nuclear reactions, such as knockout and fragmentation, present large modifications of particle type and energies of the galactic cosmic rays in penetrating materials. We make an assessment of the current nuclear reaction models and improvements in these model for developing required transport code data bases. A new fragmentation data base (QMSFRG) based on microscopic models is compared to the NUCFRG2 model and implications for shield assessment made using the HZETRN radiation transport code. For deep penetration problems, the build-up of light particles, such as nucleons, light clusters and mesons from nuclear reactions in conjunction with the absorption of the heavy ions, leads to the dominance of the charge Z = 0, 1, and 2 hadrons in the exposures at large penetration depths. Light particles are produced through nuclear or cluster knockout and in evaporation events with characteristically distinct spectra which play unique roles in the build-up of secondary radiation's in shielding. We describe models of light particle production in nucleon and heavy ion induced reactions and make an assessment of the importance of light particle multiplicity and spectral parameters in these exposures.
authors.affiliation: NASA, Langley Research Center, Hampton, VA 23681-0001, USA.
authors.forename: F A
authors.initials: FA
authors.lastname: Cucinotta
authors.forename: J W
authors.initials: JW
authors.lastname: Wilson
authors.forename: J L
authors.initials: JL
authors.lastname: Shinn
authors.forename: R K
authors.initials: RK
authors.lastname: Tripathi
mesh_terms: D000337:Aerospace Medicine; D000401:Aircraft; D000512:Alpha Particles; D001272:Atmosphere; D003359:Cosmic Radiation; D004601:Elementary Particles; D018499:Linear Energy Transfer; D008962:Models, Theoretical; D009502:Neutrons; D009686:Nuclear Physics; D011789:Quantum Theory; D011835:Radiation Protection; D018570:Risk Assessment; D012542:Scattering, Radiation; D018531:Spacecraft