Nuclear Fragmentation Cross Sections for NASA Database Development

Nuclear Fragmentation Cross Sections for NASA Database Development

Author:

Publisher:

Published: 2001

Total Pages: 5

ISBN-13:

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Heavy ions with energies of hundreds to thousands of MeV/nucleon are present in the Galactic Cosmic Rays and will be a source of risk to astronaut health when long-duration crewed missions are undertaken. Nuclear interactions of these GCR ions in shielding materials must be accurately modeled by transport codes in order to estimate the dose and dose equivalent at points inside a spacecraft. Uncertainties in the nuclear fragmentation cross sections are propagated into these estimates, and the overall uncertainties increase as shielding depth increases. A program of fragmentation cross section measurements has therefore been undertaken to reduce these uncertainties, using GCR-like ion species and energies in particle accelerators in the United States, at the Brookhaven National Laboratory's Alternating Gradient Synchrotron (AGS) and in Japan at the National Institute of Radiological Science's Heavy Ion Medical Accelerator in Chiba (HIMAC). An extensive set of data has been obtained with beams ranging from helium to iron and including most of the species that are prominent in the GCR.


Nuclear Fragmentation Cross Section Modeling for Space Radiation Applications

Nuclear Fragmentation Cross Section Modeling for Space Radiation Applications

Author: Wouter C. de Wet

Publisher:

Published: 2017

Total Pages: 87

ISBN-13:

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One of the most significant challenges to overcome on the journey to Mars is understanding the biological risk associated with the space radiation environment. Radiation transport codes are one of the tools necessary to quantify this risk. Due to the nature of the space radiation environment, it is of great importance that these transport codes are able to describe the breakup of heavy ions into smaller fragments--light ions in particular. For this, event generators within radiation transport codes rely on nuclear fragmentation codes to predict the products of high energy nuclear collisions. This manuscript documents the development of a nuclear fragmentation code: the Relativistic Abrasion-Ablation and Deexcitation Fragmentation Model (RAADFRG). RAADFRG is the product of a collaboration between the University of Tennessee and NASA's Langley Research Center (LaRC), and is being developed for space radiation applications. Currently, total isotopic yield is of primary concern; however, future versions of the model must predict double differential isotopic yields. The collision model is a framework of smaller physics packages, each meant to describe a specific physical phenomenon within the abrasion-ablation heavy ion collision theory. The coalescence model, along with the collision framework architecture and development, are my primary original contributions.


Proton-Nucleus Total Cross Sections in Coupled-Channel Approach

Proton-Nucleus Total Cross Sections in Coupled-Channel Approach

Author: R. K. Tripathi

Publisher:

Published: 2000

Total Pages: 18

ISBN-13:

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Recently, nucleon-nucleon (N-N) cross sections in the medium have been extracted directly from experiment. The in-medium N-N cross sections form the basic ingredients of several heavy-ion scattering approaches including the coupled-channel approach developed at the Langley Research Center. In the present study the ratio of the real to the imaginary part of the two-body scattering amplitude in the medium was investigated. These ratios are used in combination with the in-medium N-N cross sections to calculate total proton-nucleus cross sections. The agreement is excellent with the available experimental data. These cross sections are needed for the radiation risk assessment of space missions.


Tables of Nuclear Cross Sections for Galactic Cosmic Rays

Tables of Nuclear Cross Sections for Galactic Cosmic Rays

Author: Lawrence W. Townsend

Publisher:

Published: 1985

Total Pages: 40

ISBN-13:

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A simple but comprehensive theory of nuclear reactions is presented. Extensive tables of nucleon, deuteron, and heavy-ion absorption cross sections over a broad range of energies are generated for use in cosmic ray shielding studies. Numerous comparisons of the calculated values with available experimental data show agreement to within 3 percent for energies above 80 MeV/nucleon and within approximately 10 percent for energies as low as 30 MeV/nucleon. These tables represent the culmination of the development of the absorption cross section formalism and supersede the preliminary absorption cross sections published previously in NASA TN D-8107, NASA TP-2138, and NASA TM-84636.


Nucfrg2: An Evaluation of the Semiempirical Nuclear Fragmentation Database

Nucfrg2: An Evaluation of the Semiempirical Nuclear Fragmentation Database

Author: National Aeronautics and Space Adm Nasa

Publisher: Independently Published

Published: 2018-11

Total Pages: 52

ISBN-13: 9781729356593

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A semiempirical abrasion-ablation model has been successful in generating a large nuclear database for the study of high charge and energy (HZE) ion beams, radiation physics, and galactic cosmic ray shielding. The cross sections that are generated are compared with measured HZE fragmentation data from various experimental groups. A research program for improvement of the database generator is also discussed. Wilson, J. W. and Tripathi, R. K. and Cucinotta, F. A. and Shinn, J. L. and Badavi, F. F. and Chun, S. Y. and Norbury, J. W. and Zeitlin, C. J. and Heilbronn, L. and Miller, J. Langley Research Center RTOP 199-45-16-11...