Coupled neutron transport for HZETRN

Slaba, Tony C.; Blattnig, Steve R.; Aghara, Sukesh K.; Townsend, Lawrence W.; Handler, T.; Gabriel, T.A.; Pinsky, L.; Reddell, Brandon

doi:10.1016/j.radmeas.2010.01.005

Cited by 61 publications

(54 citation statements)

References 20 publications

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“…HZETRN (Wilson et al 1991;Slaba et al 2010aSlaba et al , 2010bSlaba et al , 2013Norman et al 2013) is a deterministic transport code providing numerical solutions to the time-independent, linear Boltzmann equation (Wilson et al 1991). The transport formalism allows for a converging sequence of physical approximations to be considered, allowing highly efficient computational procedures to be implemented.…”

Section: Hzetrn/oltarismentioning

confidence: 99%

“…Typical run times for full GCR calculations range from seconds to minutes on a single CPU. The version of the code used herein utilizes a bidirectional transport approach for neutrons and light ions (Slaba et al 2010a), allowing backscattered albedo neutron contributions to be described in the present comparisons. Heavier ions are treated within the Calculations were performed taking into account all primary nuclei from hydrogen to iron.…”

Section: Hzetrn/oltarismentioning

confidence: 99%

“…Several numerical models exist that can calculate the transport of primary nuclei from the GCR through the Martian atmosphere and the backscattering from the soil. The following models are investigated in this work: HZETRN/OLTARIS (Wilson et al 1991;Slaba et al 2010aSlaba et al , 2010bSlaba et al , 2013Singleterry et al 2011;Norman et al 2013), GEANT4/PLANETOCOSMICS (Agostinelli et al 2003;Allison et al 2006), and PHITS (Niita et al 2006;Sato et al 2013). These transport models, which are discussed in more detail below, have to be combined with models of the primary GCR spectra taking into account the solar modulation.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The Martian surface radiation environment – a comparison of models and MSL/RAD measurements

Matthiä

Ehresmann

Lohf

et al. 2016

J. Space Weather Space Clim.

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Context: The Radiation Assessment Detector (RAD) on the Mars Science Laboratory (MSL) has been measuring the radiation environment on the surface of Mars since August 6th 2012. MSL-RAD is the first instrument to provide detailed information about charged and neutral particle spectra and dose rates on the Martian surface, and one of the primary objectives of the RAD investigation is to help improve and validate current radiation transport models. Aims: Applying different numerical transport models with boundary conditions derived from the MSL-RAD environment the goal of this work was to both provide predictions for the particle spectra and the radiation exposure on the Martian surface complementing the RAD sensitive range and, at the same time, validate the results with the experimental data, where applicable. Such validated models can be used to predict dose rates for future manned missions as well as for performing shield optimization studies. Methods: Several particle transport models (GEANT4, PHITS, HZETRN/OLTARIS) were used to predict the particle flux and the corresponding radiation environment caused by galactic cosmic radiation on Mars. From the calculated particle spectra the dose rates on the surface are estimated. Results: Calculations of particle spectra and dose rates induced by galactic cosmic radiation on the Martian surface are presented. Although good agreement is found in many cases for the different transport codes, GEANT4, PHITS, and HZETRN/OLTARIS, some models still show large, sometimes order of magnitude discrepancies in certain particle spectra. We have found that RAD data is helping to make better choices of input parameters and physical models. Elements of these validated models can be applied to more detailed studies on how the radiation environment is influenced by solar modulation, Martian atmosphere and soil, and changes due to the Martian seasonal pressure cycle. By extending the range of the calculated particle spectra with respect to the experimental data additional information about the radiation environment is gained, and the contribution of different particle species to the dose is estimated.

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Section: Hzetrn/oltarismentioning

confidence: 99%

Section: Hzetrn/oltarismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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The Martian surface radiation environment – a comparison of models and MSL/RAD measurements

Matthiä

Ehresmann

Lohf

et al. 2016

J. Space Weather Space Clim.

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“…Important updates to the numerical solution of light-particle transport in HZETRN have been made recently by Slaba et al (2010a;. These updates have significantly improved accuracy and computation efficiency.…”

Section: Atmospheric Cosmic Ray Transportmentioning

confidence: 99%

Atmospheric Ionizing Radiation from Galactic and Solar Cosmic Rays

Mertens¹,

Kress²,

Wiltberger³

et al. 2012

Current Topics in Ionizing Radiation Research

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“…A recent update to HZETRN includes a directionally-coupled forward-backward lowenergy neutron transport algorithm, with coupling to light-ion transport [Slaba et al, 2008]. The new deterministic transport algorithm was compared to Monte Carlo codes HETC-HEDS, FLUKA, and MCNPX for the February, 1956 SEP event using the socalled Webber spectrum.…”

Section: Low-energy Neutron Transportmentioning

confidence: 99%

Development of Nowcast of Atmospheric Ionizing Radiation for Aviation Safety (NAIRAS) Model

Mertens

Tobiska

Bouwer

et al. 2009

1st AIAA Atmospheric and Space Environments Conference

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In this paper an overview is given of the development of a new nowcast prediction of aircrew radiation exposure from both background galactic cosmic rays (GCR) and solar energetic particle events (SEP) that may accompany solar storms. The new air-crew radiation exposure model is called the Nowcast of Atmospheric Ionizing Radiation for Aviation Safety (NAIRAS) model. NAIRAS will provide global, data-driven, real-time radiation exposure predictions of biologically harmful radiation at commercial airline altitudes. Observations are utilized from the ground (neutron monitors), from the atmosphere (the NCEP Reanalysis and NCEP Global Forecasting System), and from space (NASA/ACE and NOAA/GOES). Atmospheric observations provide the overhead shielding information and the ground-and space-based observations provide boundary conditions on the incident GCR and SEP particle flux distributions for transport and dosimetry simulations. Exposure rates are calculated using the physics-based HZETRN (High Charge and Energy Transport) code. Recent progress in the model implementation is reported and examples of the model results are shown for a representative high-energy SEP event during the Halloween 2003 superstorm, with emphasis on the high-latitude and polar region. The suppression of the geomagnetic cutoff rigidity during these storm periods and their subsequent influence on atmospheric radiation exposure is characterized. System ArchitectureIn its first year of performance, using rapid-prototyping methods, Space Environment Technologies (SET) has used team member (stake-holder) participation to identify the critical input data streams. As a result, the NAIRAS high-level design architecture 1st AIAA Atmospheric and Space Environments Conference 22

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Coupled neutron transport for HZETRN

Cited by 61 publications

References 20 publications

The Martian surface radiation environment – a comparison of models and MSL/RAD measurements

The Martian surface radiation environment – a comparison of models and MSL/RAD measurements

Atmospheric Ionizing Radiation from Galactic and Solar Cosmic Rays

Development of Nowcast of Atmospheric Ionizing Radiation for Aviation Safety (NAIRAS) Model

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