FLUX: Space Ionizing Radiation Environment Model

Overview

The CREME FLUX module provides a numerical model of the space ionizing-radiation environment at the surface of the spacecraft, before transport through shielding. After running FLUX for the environment and orbit in which you are interested, you must run the TRANS program to transport the particle fluxes through shielding.

• If you are interested in geosynchronous or near-Earth interplanetary orbits, FLUX is your starting point for CREME calculations.
• If you are interested in orbits inside Earth's magnetosphere, you must run one or both of the following programs before running FLUX:
  • GTRN: This program accounts for the shielding provided by Earth's magnetic field.
  • TRP: This module evaluates fluxes of particles trapped in Earth's magnetic fields. (You can either run TRP and process trapped proton spectra through shielding, SEE-rate routines, etc. separately OR you can add the trapped protons spectra to the other non-trapped components described by FLUX. See TRP Option for further details.)

Inputs

In running FLUX, you must:

• Specify the range of atomic numbers to be included.
• Select an environment model.
• Specify the type of orbit.

Output

FLUX writes the particle fluxes to an output file ("something.flx"), whose rootname "something" you specify; the extension ".flx" is added automatically by FLUX.

This file is produced by the FLUX routine and contains the differential fluxes of various species (in nuclei/m²-s-sr-MeV/nuc) vs. kinetic energy (in MeV/nuc) at the external surface of the spacecraft, before transport through shielding.

FLUX output files must have a name of the form "something.flx ". (That is, a rootname which you specify; the extension "flx" is added automatically.) This extension also identifies the file as having a special format, which is required for input to other CREME routines. The .flx file also contains header information which documents the inputs and parameters which produced it.

.flx files contain particle fluxes at energies from 1 to 10⁵ MeV/nuc. The special format of the CREME96 .flx files suppresses the energy values. This format may be decoded into two-column tables (with energy in MeV/nuc in the first column and flux in nuclei/m²-s-sr-MeV/nuc in the second column)

Once you have calculated this output file for the environment and orbit in which you are interested, it can serve as the starting point for many additional calculations for different depths of shielding and devices.

See also: Plotting CREME96 Spectra