AMS (Alpha Magnetic Spectrometer)
Particle physics goes in Space
ASI and Italy are at the forefront in the implementation of an ambitious orbiting laboratory for particle physics. It is the Alpha Magnetic Spectrometer (AMS), which aims to study cosmic rays in search of traces of antimatter and dark matter, and that sees Italy as the first contributor, with about 25% of the total. Italy, with the Italian Space Agency and the National Institute of Nuclear Physics, is responsible for the implementation of the main instruments on board of AMS. The national space industry, under the management of ASI, contributed in particular to the realization of the thermal system and silicon detectors. In 1998 a prototype experiment has made a successful first flight on the Shuttle. The AMS was brought into orbit May 16, 2011 with the penultimate shuttle mission, STS-134, to be subsequently docked to the International Space Station.
Able to identify and antiparticles antinuclei with an accuracy of one part per billion, AMS aims to become the Hubble Space Telescope of cosmic rays. It will measure the composition of cosmic radiation with energy between 100 MeV and 5 TeV. Designed on the model of the accelerators at CERN and laboratories of the National Institute of Nuclear Physics (INFN) in Frascati, consists of a permanent magnet, whose detectors are able to identify the type of particles through measures redundant charge, speed, energy and direction of motion.
Italian Space Agency and INFN collaborate and support this experiment since 1995, as part of an international collaboration that includes 16 countries and 64 institutions, according to the organizational model typical of the experiments at CERN.
The particle detectors have been designed and built with the help of researchers from the National Institute of Nuclear Physics (INFN) in Bologna, Milan, Perugia, Pisa and Rome La Sapienza.
The results are presented in two articles published on September 18, 2014 in Physical Review Letters describing the results to the international community to the extent of positrons up to energies of 500 GeV and electrons at energies up to 700 GeV, based on 10 million electrons and positrons identified between 41 billion cosmic rays collected in the first 30 months of the mission. These results extend and enhance the first observations published in the spring of 2013. The new measures will reach a limit of energy unexplored for these components of cosmic radiation and, thanks to their precision, open new horizons in the search for unknown phenomena taking place in the our universe.
The scientific objectives for AMS are those that expect answers to problems that are the basis of elementary particle physics. In particular the study of the nature of dark matter by searching for distortions in the spectra of particles and antiparticles rare (high-energy gamma rays, poitroni, antiprotons, antideuterio) and direct search of antinuclei with a sensitivity of one part per billion should be decisive in this regard.
AMS also make precision measurements of the composition of all components charged cosmic rays up to a stiffness of about 5 TeV.