‘The Alpha Magnetic Spectrometer on the International Space Station’

There are two types of cosmic rays that reach Earth from outer space. The first type are electrically neutral (photons and neutrinos), whose study using spaceborne, ground-based and underground telescopes and detectors has contributed greatly to our understanding of the Universe. The second type of cosmic rays carry charge and mass and are absorbed in the Earth’s atmosphere. Their study calls for a precision magnetic spectrometer located in space, beyond the atmosphere, to identify their mass, electrical charge, energy and directionality. The Alpha Magnetic Spectrometer (AMS) is a precision particle physics detector deployed on the International Space Station in May 2011, which in its first four years measured 76 billion cosmic rays. The precision of the detector and its ability to measure and distinguish cosmic atomic nuclei have changed our understanding of the properties of charged cosmic rays.