title: Microscopic fragmentation model for galactic cosmic ray studies.
abstract: We describe theoretical considerations for developing models of heavy ion fragmentation appropriate for galactic cosmic ray studies. Previous models have been based on parametric fits to limited experimental data or models that ignored some aspects of the reaction dynamics, including nuclear cluster effects. The abrasion-ablation description of the fragmentation process is re-formulated to describe the excitation spectrum of pre-fragment nuclei. The resulting spectrum is shown to be related to the many-body response of the nuclear ground-state and excited states, and an approach to simplify this function is discussed. An analytic solution to the nuclear de-excitation process is described which includes a realistic level spectrum of the GCR nuclei (A < 60). Comparisons are made to experiments for fragmentation of 24Mg, 32S, and 56Fe beams on several targets and results are discussed.
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: R K
authors.initials: RK
authors.lastname: Tripathi
authors.forename: L W
authors.initials: LW
authors.lastname: Townsend
mesh_terms: D003359:Cosmic Radiation; D019471:Elementary Particle Interactions; D020450:Heavy Ions; D007501:Iron; D008274:Magnesium; D008962:Models, Theoretical; D009686:Nuclear Physics; D011789:Quantum Theory; D013455:Sulfur
chemical_list: D013455:Sulfur; D007501:Iron; D008274:Magnesium