By properly masking the sunward direction, SWAPI makes critical measurements of the solar wind conditions at 1 AU, including H+, He++, and heavier ions during cold solar wind conditions such as in many interplanetary coronal mass ejections (ICMEs). Away from the solar wind direction, there is no aperture reduction, increasing PUI sensitivity by 5× compared to SWAP. The SWAPI energy range is extended up to 20 keV/q to capture the 1D He+ and H+ PUI distributions and cutoffs, as well as both the solar wind H+ and He++.
All schematics and numbers are preliminary as of the beginning of Phase A. Additional information about each instrument can be found in the Open Access IMAP Paper.