The heliocentric potential enables the program to adjust for changes in galactic radiation levels that occur with changes in solar activity. The program employs the user-entered flight date to select the appropriate heliocentric potential from its database. The program will prompt the user in entering heliocentric potentials for dates not already in the database. There may be a lag of up to one month in availability of heliocentric potential data on our Web site.

To estimate flight doses during the current month, use the most recent heliocentric potential available. Do not use a heliocentric potential more than two months removed from the month of interest. Flight doses for specific flight profiles normally change very little in a couple of months. To compare CARI-6 or CARI-6M dose estimates with instrument measurements, we recommend using heliocentric potentials appropriate for the days or hours of the measurements. We will provide these heliocentric potentials on request.

Please email us if you would like additional information about Heliocentric Potentials.

Also, please see our Office of Aerospace Medicine technical report entitled Ionizing Radiation in Earth's Atmosphere and in Space Near Earth (PDF)

The values in the table shown below are available in this MS Excel file (MS Excel). Values formatted for use in CAR-6 and CARI-7 for the period 1958 to present are available in this zip file (Zip).

Heliocentric potentials for recent months (last 12 months) are preliminary. The data above is based on ground level neutron measurements provided by Dr. Eduard Vashenyuk of the Apatity Cosmic Ray Station of the Polar Geophysical Institute, Russia.