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CARI-7 and CARI-7A

The CARI-7 computer program, developed at the FAA's Civil Aerospace Medical Institute, calculates the effective dose of galactic cosmic radiation received by an individual (based on an anthropomorphic phantom) on an aircraft. The program will accommodate both waypoint defined and shortest route (geodesics) flight paths. Particle specific doses, can also be calculated for route or at specific locations. The altitude limit is now 300,000 ft. Calculations dating to 1958 are possible without providing added data.

Thus, CARI-7 replaces CARI-6, -6M, -6P, -6PM, C6, and -6W. The program can run using internal menus or be used in scripts, depending on user selections in the initialization files. Like previous versions, the program uses a command prompt interface and can be run on most personal computers. The files use approximately 80 MB of disc space and up to 42 MB of RAM. The output files are typically small (kb), and will slowly get larger if writing the diagnostic output is off.

As did the previous version of CARI, the program takes into account changes in altitude and geographic location during the course of a flight, based on information provided by the user. For monthly average calculations, databases are used to account for effects of changes in the earth's magnetic field and solar activity on galactic radiation levels in the atmosphere. Flights may also be specified for specific hours of specific days, though this will increase calculation times to accommodate adjustments for geomagnetic storms and Forbush effects, if any, on GCR levels at during the flight.

CARI-7A differs from CARI-7 in that it is intended for academic/research-focused users and has more run time options, including three atmospheric transport switches (superposition approximation, non-vertical cutoffs, beam-like particle transport approximation), multiple GCR and solar particle event models including an option for a custom input particle spectrum, and also requires more file upkeep to keep the extra models current. CARI-7A is somewhat bigger then CARI-7, requiring approximately 100 MB of disc space, using up to 50 MB of RAM, and currently runs several hundred times slower (about 1 second per location), due to the extra calculation burden of the added options. We continually strive to enahnce the performance of the routines.

The general purpose Monte Carlo particle transport program MCNPX2.7.0 was used to generate the atmospheric response databases referenced by CARI-7/7A.

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