The power supply system of the particle tracker detector for the AMS experiment

The AMS (Alpha Magnetic Spectrometer) experiment is designed to search for the antimatter components of cosmic rays, the products of the annihilation of dark matter particles and to perform additional cosmic-ray measurements like spectrum of light nuclei, antiprotons and positrons as well as isotopic composition for light elements. The complete AMS instrument will be installed on the International Space Station (ISS) in year 2003. A preliminary version of the apparatus has flown in June 1998 on the Space Shuttle mission STS-91. The power supply system of the tracker, described in this paper, has been constructed optimizing noise performances, following space qualification criteria for a ten day mission on the shuttle and considering the operation in the fringe magnetic field of the spectrometer. This paper also includes a short description of tracker electronics. Optimisation and qualification tests on the complete power supply system are reported. Even if most of the paper refers to the Shuttle flight version of the paper supply, guidelines for the design of the ISS flight version are given in the conclusions.