Observation of transiron solar-flare nuclei in an Apollo 16 command-module window

The first measurements of the fluence of solar particles with nuclear charges not less than 32 and 44 are presented, along with the enhancement factors found. Using a track-etching technique, these transiron nuclei were detected in a window from the Apollo 16 command module which was exposed outside the magnetosphere during the solar-particle event of Apr. 18, 1972.