The Alpha Magnetic Spectrometer on the International Space Station

The Alpha Magnetic Spectrometer (AMS) is a particle physics detector designed to measure charged cosmic ray spectra up to TeV region, with high-energy photon detection capability up to few hundred GeV. AMS is a superconducting spectrometer with large acceptance, long duration (3 years) and state of the art particle identification techniques, AMS will investigate the composition of cosmic rays with high statistics and provide the most sensitive search for the existence of anti matter nuclei and for the origin of dark matter. The detector is being constructed with an eight layers silicon tracker inside a large superconducting magnet, providing a ∼0.8 Tm² bending power and an acceptance of ∼0.5 m² sr. A transition radiation detector and a 3D electromagnetic calorimeter allow for electron, positron and photon identification, while independent velocity measurements are performed by a time of flight scintillating system and a ring image Cerenkov detector. This complex apparatus will identify and measure nuclei up to iron. This contribution will describe the overall detector construction and performance, which is due to be completed by 2005. The detector will be installed on ISS (International Space Station) in 2008.