title: Nonperturbative methods in HZE propagation.
abstract: An analytical solution to the perturbative multiple collision series of a fragmenting HZE ion beam has limited usefulness since the first collision term has several hundred contributions, the second collision term has tens of thousands of contributions, and each successive collision term progresses to unwieldy computational proportions. Our previous work has revealed the multiple collision terms in the straight-ahead approximation to be simple products of a spatially dependent factor times a linear energy-dependent factor of limited domain and unit normalization. The properties of these forms allow the development of the nonperturbative summation of the series to all orders assuming energy-independent nuclear cross sections as matrix products of a scaled Green's function described herein. This nonperturbative Green's function with multiple scattering correction factors compares well with experiments using 670 MeV/u neon-20 ion beams in thick water targets.
authors.affiliation: National Aeronautics and Space Administration, Langley Research Center, Hampton, Virginia 23681-0001.
authors.forename: J W
authors.initials: JW
authors.lastname: Wilson
authors.forename: M R
authors.initials: MR
authors.lastname: Shavers
authors.forename: F F
authors.initials: FF
authors.lastname: Badavi
authors.forename: J
authors.initials: J
authors.lastname: Miller
authors.forename: J L
authors.initials: JL
authors.lastname: Shinn
authors.forename: R C
authors.initials: RC
authors.lastname: Costen
mesh_terms: D003359:Cosmic Radiation; D008433:Mathematics