Overview Of Hzetrn And Brntrn Space Radiation Shielding Codes PDF Download
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Author | : National Aeronautics and Space Adm Nasa |
Publisher | : Independently Published |
Total Pages | : 26 |
Release | : 2018-12-28 |
Genre | : |
ISBN | : 9781792719264 |
Download Overview of Hzetrn and Brntrn Space Radiation Shielding Codes Book in PDF, ePub and Kindle
The NASA Radiation Health Program has supported basic research over the last decade in radiation physics to develop ionizing radiation transport codes and corresponding data bases for the protection of astronauts from galactic and solar cosmic rays on future deep space missions. The codes describe the interactions of the incident radiations with shield materials where their content is modified by the atomic and nuclear reactions through which high energy heavy ions are fragmented into less massive reaction products and reaction products are produced as radiations as direct knockout of shield constituents or produced as de-excitation products in the reactions. This defines the radiation fields to which specific devices are subjected onboard a spacecraft. Similar reactions occur in the device itself which is the initiating event for the device response. An overview of the computational procedures and data base with some applications to photonic and data processing devices will be given. Wilson, John W. and Cucinotta, F. A. and Shinn, J. L. and Simonsen, L. C. and Badavi, F. F. Langley Research Center ...
Author | : Martha S. Clowdsley |
Publisher | : |
Total Pages | : 44 |
Release | : 2000 |
Genre | : Neutron cross sections |
ISBN | : |
Download An Improved Elastic and Nonelastic Neutron Transport Algorithm for Space Radiation Book in PDF, ePub and Kindle
In addition, a high-energy bidirectional neutron source based on a formula by Ranft showed even further improvement of the fluence results over previous results near the front of the water target where diffusion out the front surface is important. Effects of improved interaction cross sections are modest compared with the addition of the high-energy bidirectional source terms.
Author | : National Aeronautics and Space Adm Nasa |
Publisher | : Independently Published |
Total Pages | : 38 |
Release | : 2019 |
Genre | : Science |
ISBN | : 9781792736865 |
Download Fully Energy-Dependent Hzetrn (a Galactic Cosmic-Ray Transport Code) Book in PDF, ePub and Kindle
For extended manned space missions, the radiation shielding design requires efficient and accurate cosmic-ray transport codes that can handle the physics processes in detail. The Langley Research Center galactic cosmic-ray transport code (HZETRN) is currently under development for such design use. The cross sections for the production of secondary nucleons in the existing HZETRN code are energy dependent only for nucleon collisions. The approximation of energy-independent, heavy-ion fragmentation cross section is now removed by implementing a mathematically simplified energy-dependent stepping formalism for heavy ions. The cross section at each computational grid is obtained by linear interpolation from a few tabulated data to minimize computing time. Test runs were made for galactic cosmic-ray transport through a liquid hydrogen shield and a water shield at solar minimum. The results show no appreciable change in total fluxes or computing time compared with energy-independent calculations. Differences in high LET (linear energy transfer) spectra are noted, however, because of the large variation in cross sections at the low-energy region. The high LET components are significantly higher in the new code and have important implications on biological risk estimates for heavy-ion exposure. Shinn, Judy L. and John, Sarah and Tripathi, Ram K. and Norbury, John W. and Wilson, John W. and Townsend, Lawrence W. Langley Research Center NASA-TP-3243, L-17103, NAS 1.61:3243 RTOP 593-42-21-01...
Author | : |
Publisher | : |
Total Pages | : 180 |
Release | : 1997 |
Genre | : Aeronautics |
ISBN | : |
Download NASA Technical Memorandum Book in PDF, ePub and Kindle
Author | : National Aeronautics and Space Administration (NASA) |
Publisher | : Createspace Independent Publishing Platform |
Total Pages | : 152 |
Release | : 2018-07-18 |
Genre | : |
ISBN | : 9781723149870 |
Download Hzetrn Book in PDF, ePub and Kindle
The high-charge-and energy (HZE) transport computer program HZETRN is developed to address the problems of free-space radiation transport and shielding. The HZETRN program is intended specifically for the design engineer who is interested in obtaining fast and accurate dosimetric information for the design and construction of space modules and devices. The program is based on a one-dimensional space-marching formulation of the Boltzmann transport equation with a straight-ahead approximation. The effect of the long-range Coulomb force and electron interaction is treated as a continuous slowing-down process. Atomic (electronic) stopping power coefficients with energies above a few A MeV are calculated by using Bethe's theory including Bragg's rule, Ziegler's shell corrections, and effective charge. Nuclear absorption cross sections are obtained from fits to quantum calculations and total cross sections are obtained with a Ramsauer formalism. Nuclear fragmentation cross sections are calculated with a semiempirical abrasion-ablation fragmentation model. The relation of the final computer code to the Boltzmann equation is discussed in the context of simplifying assumptions. A detailed description of the flow of the computer code, input requirements, sample output, and compatibility requirements for non-VAX platforms are provided. Wilson, John W. and Badavi, Francis F. and Cucinotta, Francis A. and Shinn, Judy L. and Badhwar, Gautam D. and Silberberg, R. and Tsao, C. H. and Townsend, Lawrence W. and Tripathi, Ram K. Johnson Space Center; Langley Research Center ALGORITHMS; APPLICATIONS PROGRAMS (COMPUTERS); BOLTZMANN TRANSPORT EQUATION; ELECTRON SCATTERING; NUCLEONS; RADIATION SHIELDING; RADIATION TRANSPORT; ABSORPTION CROSS SECTIONS; DOSIMETERS; ENERGY TRANSFER; FRAGMENTATION; RAMSAUER EFFECT; STOPPING POWER...
Author | : John H. Heinbockel |
Publisher | : |
Total Pages | : 38 |
Release | : 2000 |
Genre | : Extraterrestrial radiation |
ISBN | : |
Download An Improved Neutron Transport Algorithm for Space Radiation Book in PDF, ePub and Kindle
Author | : National Aeronautics and Space Administration (NASA) |
Publisher | : Createspace Independent Publishing Platform |
Total Pages | : 36 |
Release | : 2018-08-16 |
Genre | : |
ISBN | : 9781725094031 |
Download An Efficient Hzetrn (a Galactic Cosmic Ray Transport Code) Book in PDF, ePub and Kindle
An accurate and efficient engineering code for analyzing the shielding requirements against the high-energy galactic heavy ions is needed. The HZETRN is a deterministic code developed at Langley Research Center that is constantly under improvement both in physics and numerical computation and is targeted for such use. One problem area connected with the space-marching technique used in this code is the propagation of the local truncation error. By improving the numerical algorithms for interpolation, integration, and grid distribution formula, the efficiency of the code is increased by a factor of eight as the number of energy grid points is reduced. The numerical accuracy of better than 2 percent for a shield thickness of 150 g/cm(exp 2) is found when a 45 point energy grid is used. The propagating step size, which is related to the perturbation theory, is also reevaluated. Shinn, Judy L. and Wilson, John W. Langley Research Center NASA-TP-3147, L-16954, NAS 1.60:3147 RTOP 593-42-21...
Author | : Sarah Baatout |
Publisher | : Springer Nature |
Total Pages | : 687 |
Release | : 2023-09-23 |
Genre | : Science |
ISBN | : 3031188101 |
Download Radiobiology Textbook Book in PDF, ePub and Kindle
This open access textbook focuses on the various aspects of radiobiology. The goal of radiobiological research is to better understand the effects of radiation exposure at the cellular and molecular levels in order to determine the impact on health. This book offers a unique perspective, by covering not only radiation biology but also radiation physics, radiation oncology, radiotherapy, radiochemistry, radiopharmacy, nuclear medicine, space radiation biology & physics, environmental and human radiation protection, nuclear emergency planning, molecular biology and bioinformatics, as well as the ethical, legal and social considerations related to radiobiology. This range of disciplines contributes to making radiobiology a broad and rather complex topic. This textbook is intended to provide a solid foundation to those interested in the basics and practice of radiobiological science. It is a learning resource, meeting the needs of students, scientists and medical staff with an interest in this rapidly evolving discipline, as well as a teaching tool, with accompanying teaching material to help educators.
Author | : |
Publisher | : |
Total Pages | : 338 |
Release | : 1996 |
Genre | : Photonics |
ISBN | : |
Download Photonics for Space Environments Book in PDF, ePub and Kindle
Author | : |
Publisher | : |
Total Pages | : 2092 |
Release | : 1997 |
Genre | : Electrical engineering |
ISBN | : |
Download Electrical & Electronics Abstracts Book in PDF, ePub and Kindle