The NUCLEON space experiment for direct high energy cosmic rays investigation in TeV-PeV energy range

The NUCLEON satellite experiment is designed to investigate directly, above the atmosphere, the energy spectra of cosmic-ray nuclei and the chemical composition from 100 GeV to 1000 TeV as well as the cosmic-ray electron spectrum from 20 GeV to 3 TeV. NUCLEON is planned to be launched in 2014. This mission is aimed at clarifying the essential details of cosmic-ray origin in this energy interval: number and types of sources, identification of actual nearby sources, and the investigation of the mechanisms responsible for the knee. Specific features of the NUCLEON instrument are relatively small thickness and small weight. A special method of energy determination by the silicon tracker was developed for this case. In this paper we describe a design of the instrument and the results of accelerator beam tests in terms of charge and energy resolution. The overall evidences of the capability of the apparatus to achieve the declared aims are also presented.