Exposure estimates inside space vehicles, surface habitats, and high altitude aircraft exposed to space radiation are highly influenced by secondary neutron production. The deterministic transport code HZETRN has been identified as a reliable and efficient tool for such studies, but improvements to the underlying transport models and numerical methods are still necessary. In this paper, the forward-backward (FB) and directionally coupled forward-backward (DC) neutron transport models are derived, numerical methods for the FB model are reviewed, and a computationally efficient numerical solution is presented for the DC model. Both models are compared to the Monte Carlo codes HETC-HEDS and FLUKA, and the DC model is shown to agree closely with the Monte Carlo results. Finally, it is found in the development of either model that the decoupling of low energy neutrons from the light ion (A≤4) transport procedure adversely affects low energy light ion fluence spectra and exposure quantities. A first order correction is presented to resolve the problem, and it is shown to be both accurate and efficient.
Neutron Transport Models and Methods for HZETRN and Coupling to Low Energy Light Ion Transport
Sae Int. J. Aerosp
International Conference On Environmental Systems ; 2008
Sae International Journal of Aerospace ; 1 , 1 ; 510-521
2008-06-29
12 pages
Conference paper
English
Neutron Transport Models and Methods for HZETRN and Coupling to Low Energy Light Ion Transport
British Library Conference Proceedings | 2008
|An improved neutron transport algorithm for HZETRN
Online Contents | 2010
|Computational methods for the HZETRN code
Online Contents | 2005
|Computational methods for the HZETRN code
British Library Conference Proceedings | 2005
|Comparison of the transport codes HZETRN, HETC and FLUKA for galactic cosmic rays
Online Contents | 2011
|