Editing Explorer 7 (section)

=== Heavy Primary Cosmic Rays ===
This experiment was designed to measure the omnidirectional flux of heavy primary cosmic rays in the rigidity range 1 to 15.5 [[Volt|GV]]. Particles with atomic numbers Z >5, Z >8, and Z >15 were counted separately by an ionization chamber in which each incident particle yielded a pulse. Pulse amplitude was substantially independent of the energy of the incident particle but was proportional to the square of its Z value. Each of the three counting rates was determined every 15 seconds. The experiment performed as planned from launch until 25 October 1959. About 80% of the data acquired for the 25 October 1959, to 31 May 1960, period are useful, with most problems occurring in the lowest Z mode. Very little useful data were acquired after 31 May 1960.<ref name="Instrument3">{{cite web |url=https://nssdc.gsfc.nasa.gov/nmc/experiment/display.action?id=1959-009A-03|title=Experiment: Heavy Primary Cosmic Rays|publisher=NASA|date=28 October 2021|access-date=2 November 2021}} {{PD-notice}}</ref>