AMS2

Home page of the Experiment: http://ams.pg.infn.it/ams-italy/ams.htm

http://ams.cern.ch/AMS/ams_homepage.html AMS-02 CERN http://cyclo.mit.edu/~bmonreal/frames.what.html AMS for the general public

The high statistics measurement of the CR in space, enabled for the first time the study of the behaviour of primary CR near Earth in the rigidity interval from 0,1 Gev to 200 GeV, at all longitudes and latitudes up to 51.7o. Search of antimatter requires the capability to identify with the highest degree of confidence, the type of particle traversing the experiment together with the absolute value and the sign of its electric charge.
This can be achieved through repeated measurements of the particle momentum (solid state spectrometer based on a 6 layer Silicon Tracker located in a permanent magnet), velocity (Time of Flight, Transition Radiation detectors, Cerenkov detectors) and energy deposition (Ionization detectors). AMS consist of a large acceptance magnetic spectrometer (about 0.6 m2sr) surrounding a six layer high precision Silicon Tracker and surrounded by a Time of Flight scintillator system (ToF). A scintillator anticounter system, located on the magnet inner wall, one Transition Radiation Tracker (TRT) located below and above the magnet, and a solid state Ring Imaging Cherenkov detector, complete the experiment. While on the Space Station the complete AMS experiment will operate for three years, a reduced configuration (baseline) has been deployed on the precursor flight. The baseline configuration included a permanent magnet, the Anticounter and the Time of Flight systems, the Silicon Tracker and an Areogel Threshold Cherenkov counter. By combining the various measurement it is possible to determine the type of particle traversing the magnet and/or to distinguish interesting particles from background with an accuracy of one part in ten billions. The search for dark matter will be based on the capability of detecting anomalies in the spectrum of antiprotons, electrons and gamma rays particles. Gamma rays are detected by their conversions in e+e- pairs on the top part of the experiment.