The first six years of AMS on the International Space Station

The AMS Experiment is a very powerful and sensitive physics detector deployed in space and is exploring a new and exciting frontier in physics research. As a magnetic spectrome-ter, AMS is unique in physics research as it studies charged particles and nuclei from origi-nal sources in the cosmos before they are annihilated in the Earth’s atmosphere. The im-provement in accuracy over previous measurements is made possible through its long du-ration time in space, large acceptance, built in redundant systems and its thorough calibra-tion in the CERN test beam. These features enable AMS to analyze the data to an accuracy of ~1% and thereby requiring new theories to be developed by the physics and astrophysics community. Since its installation on the International Space Station in May 2011, AMS has collected data from more than 90 billion cosmic rays. AMS contains seven instruments to inde-pendently identify different elementary particles as well as nuclei. Helium, lithium, carbon, oxygen and heavier nuclei up to iron have been studied by AMS. Over the past century, there have been many measurements of the electron, positron and proton spectra in cosmic rays which had large statististical and/or systematical uncertainties and created many di-verse theoretical models. Currently, AMS precision measurements have revealed new and distinct information that has changed our understanding of cosmic rays. There has been much interest over the last few decades in understanding the origin and nature of dark matter. When particles of dark matter collide, they produce energy that transforms into ordinary particles, such as positrons and antiprotons. AMS has found an excess of positrons and antiprotons in cosmic rays.