Particle Flux Files

These files contain the differential fluxes of various species (in units of nuclei/m²-s-sr-MeV/nuc) vs. kinetic energy (in MeV/nuc). Such files are produced by two programs:

• FLUX : In this case, the file contains the particle fluxes at the surface of the spacecraft, before transport through shielding. The file specifies the surface particle flux from 1 MeV/nuc to 10⁵ MeV/nuc. A FLUX output file has a name of the form "something.flx", where you specify the rootname "something" and the extension ".flx " is added automatically.
• TRANS: In this case, the file contains the particle fluxes after transport through shielding. TRANS tracks the transported particle flux down to 0.1 MeV/nuc. A TRANS output file has a name of the form "something.tfx", where you specify the rootname "something" and the extension ".tfx " is added automatically.

Please note the special extensions used in the FLUX and TRANS output file names (.flx and .tfx, respectively). Without these specific extensions, these files cannot be located by some of the CREME pull-down menus and on-line directory features. In addition, these extensions signify a special format, which is expected by other CREME routines which use these files as inputs.

File Usage:

• .flx files are generally used as inputs for the TRANS routine.
• .tfx files are generally used as inputs for the LETSPEC routine [to calculate Linear Energy Transfer (LET) spectra] and to the PUP routine [to calculate proton-induced SEU rates]
• For input to the PUP routine, the file can contain other nuclei in addition to protons; these will be ignored by PUP.
• .flx files can also be used as inputs to LETSPEC and PUP, to make calculations without shielding. (In general, however, such calculations are not recommended. See shielding thickness.)

Other features:

• CREME .flx and .tfx files also contain header information which documents the inputs and parameters which produced them.
• The CREME .flx and .tfx files are written in a special format which 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). You can download these two-column tables to your own machine for plotting with your own software. At the top of this table will be header information (with a "%" in the second column of each header line). Note that you may have to delete some or all of these lines before passing the file to your plotting software.