Primary Cosmic Ray Proton Flux Measured by AMS-02

Understand

The Alpha Magnetic Spectrometer (AMS-02) is a high energy particle detector designed to study origin and nature of cosmic rays up to a few TV from space.

• It was installed on the International Space Station (ISS) on May 19, 2011.
• During the first two years of operation AMS-02 performed precise measurements of the proton flux.
• In the low rigidity range, from 1 GV to 20 GV, the proton flux was daily measured with a statistical error less than 1%.