Welcome to OLTARIS,
Tool for the
OLTARIS is an integrated tool set utilizing HZETRN (High Charge and Energy Transport).
These tools are intended to help scientists and engineers study the effects of space
radiation on shielding materials, electronics, and biological systems.
This site is intended for users knowledgeable about space radiation and shielding concepts.
A users guide and some reference documentation can be found under the Documentation
and Links page linked above.
Added NASA Cancer Risk Model, which computes Risk of Exposure Induced Death (REID)
and Risk of Exposure Induced Cancer (REIC).
Added the capability to use the AP9 trapped radiation model for uploaded trajectories.
Added the Badhwar-O'Neil 2020 GCR model.
There are no charges associated with the use of OLTARIS, but users
must register and get approval from the site administrators
before accessing the site contents. New users should click
the Sign up link above and complete the
OLTARIS Sign Up page. After registration is complete,
one of the site administrators will activate your account when approved,
and confirmation will be sent to the supplied email address.
OLTARIS requires a standard browser with
This is an evolving tool set; new capabilities can and will be added.
Please contact the site administrator
with comments and suggestions.
User Selected Environment(s)
- Free Space Galactic Cosmic Ray (GCR)
- Badhwar-O'Neill 2010, 2014, and 2020; Matthia 2013; SINP 2016
- Select historical solar minimum or maximum and input duration
- Input start and end dates
- Input fitting parameter
- Free Space Solar Particle Event (SPE)
- Select historical spectra
- Input parameters for a specific fitting function
- Earth Orbit
- Circular orbit by start/end data, altitude, inclination
- AP8 and AP9 trapped models
- Upload user-defined trajectory
- Mars Surface Environment
- Mars-GRAM or Mars Climate Database (MCD) atmosphere models
- Albedo neutrons included
- Lunar surface with neutron albedo
- Europa Mission Design Environments
User Defined Geometry
- Upload thickness distribution(s)
- Interpolation-based analysis limited to three user-defined materials/layers
- Ray-by-ray analysis is currently limited to 5000 user-defined materials/layers
Slabs and spheres can be defined with any number of materials/layers in any order
User Defined Materials
Materials can be defined by:
Elemental Mass Percentage
Molecular Mass Percentage
User Selected Response Function(s)
Differential Flux / Fluence
Dose in tissue or silicon
Dose Equivalent (ICRP60 or NASA Q)
Whole-Body Effective Dose Equivalent CAM, CAF, MAX, and FAX (NCRP-132 or NASA tissue weights)
Risk of Exposure Induced Death (REID), Risk of Exposure Induced Cancer (REIC)
TLD-100 (Thermo-Luminescent Dosimeter)
LET (Linear Energy Transfer) in tissue or silicon
The OLTARIS development team is always in
the process of making improvements and additions to the site.
If you encounter an issue you feel is a bug in the product, please let us know about it.
You can use the links which are posted at the top of each page or those here:
Report a Bug /
Send a Comment
for reporting bugs and submitting comments.
The OLTARIS development team appreciates your feedback!
Here is a list of known issues:
If different units are selected for electron transport results (Europa environments) in multiple tabs
in one browser, the plots and downloads will be in the units that were selected last. If you stay in
the same units for all tabs, everything will be correct.
Help documents and user guides may not be up to date. If it doesn't agree with what's on the page,
it probably just needs to be updated. Please let us know.