Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 2 de 2
Filter
Add more filters










Database
Language
Publication year range
1.
Life Sci Space Res (Amst) ; 26: 10-27, 2020 Aug.
Article in English | MEDLINE | ID: mdl-32718675

ABSTRACT

3DHZETRN-v2 includes a detailed three dimensional (3D) treatment of neutron/light-ion transport based on a quasi-elastic/multiple production assumption allowing improved agreement of the neutron/light-ion fluence compared with results of three Monte Carlo (MC) codes in the sense that the variance with respect to the individual MC results is less than the variance among the MC code results. The current numerical methods are no longer the main limitation to HZETRN code development and further changes in the nuclear model are required. In a prior study, an improved quasi-elastic spectrum based on a solution of the transport approximation to nuclear media effects showed promise, but the remaining multiple-production spectrum was based on a database derived from the Ranft model that used Bertini multiplicities. In the present paper, we will implement a more complete Serber first step into the 3DHZETRN-v2 code, but we retain the Bertini-Ranft branching ratios and evaporation multiplicities. It is shown that the new Serber model in the 3HZETRN-v2 code reduces the variance with individual MC codes, which are largely due to nuclear cross section model differences. The code will be available through the software system, OLTARIS, for shield design and validation and provides a basis for personal computer software capable of space shield analysis and optimization.


Subject(s)
Neutrons , Protective Devices/statistics & numerical data , Radiation Dosage , Radiation Protection/methods , Software , Space Flight , Monte Carlo Method , Radiation Protection/instrumentation , Solar Activity
2.
Phys Med Biol ; 56(21): 6857-72, 2011 Nov 07.
Article in English | MEDLINE | ID: mdl-21983482

ABSTRACT

Recoiling hydrogen nuclei are a principle mechanism for energy deposition from incident neutrons. For neutrons incident on the human skeleton, the small sizes of two contrasting media (trabecular bone and marrow) present unique problems due to a lack of charged-particle (protons) equilibrium. Specific absorbed fractions have been computed for protons originating in the human skeletal tissues for use in computing neutron dose response functions. The proton specific absorbed fractions were computed using a pathlength-based range-energy calculation in trabecular skeletal samples of a 40 year old male cadaver.


Subject(s)
Bone and Bones/radiation effects , Diagnostic Imaging/methods , Muscle, Skeletal/radiation effects , Neutrons , Protons , Absorption , Adult , Algorithms , Bone Marrow/pathology , Bone Marrow/radiation effects , Bone and Bones/diagnostic imaging , Bone and Bones/pathology , Computer Simulation , Diagnostic Imaging/standards , Humans , Male , Models, Biological , Muscle, Skeletal/diagnostic imaging , Muscle, Skeletal/pathology , Radiation Dosage , Radiography
SELECTION OF CITATIONS
SEARCH DETAIL
...