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Comparison of dose estimates using the buildup-factor method and a Baryon transport code (BRYNTRN) with Monte Carlo resultsContinuing efforts toward validating the buildup factor method and the BRYNTRN code, which use the deterministic approach in solving radiation transport problems and are the candidate engineering tools in space radiation shielding analyses, are presented. A simplified theory of proton buildup factors assuming no neutron coupling is derived to verify a previously chosen form for parameterizing the dose conversion factor that includes the secondary particle buildup effect. Estimates of dose in tissue made by the two deterministic approaches and the Monte Carlo method are intercompared for cases with various thicknesses of shields and various types of proton spectra. The results are found to be in reasonable agreement but with some overestimation by the buildup factor method when the effect of neutron production in the shield is significant. Future improvement to include neutron coupling in the buildup factor theory is suggested to alleviate this shortcoming. Impressive agreement for individual components of doses, such as those from the secondaries and heavy particle recoils, are obtained between BRYNTRN and Monte Carlo results.
Document ID
19900019974
Acquisition Source
Legacy CDMS
Document Type
Technical Publication (TP)
Authors
Shinn, Judy L.
(NASA Langley Research Center Hampton, VA., United States)
Wilson, John W.
(NASA Langley Research Center Hampton, VA., United States)
Nealy, John E.
(NASA Langley Research Center Hampton, VA., United States)
Cucinotta, Francis A.
(Rockwell International Corp. Houston, TX., United States)
Date Acquired
September 6, 2013
Publication Date
October 1, 1990
Subject Category
Space Radiation
Report/Patent Number
L-16806
NAS 1.60:3021
NASA-TP-3021
Accession Number
90N29290
Funding Number(s)
PROJECT: RTOP 199-04-16-11
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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