Author/Authors :
Ajima، نويسنده , , Y. and Anraku، نويسنده , , K. and Haga، نويسنده , , T. and Higashi، نويسنده , , Y. and Honda، نويسنده , , H. and Imori، نويسنده , , M. and Inaba، نويسنده , , S. and Kimura، نويسنده , , N. and Kobayashi، نويسنده , , M. and Makida، نويسنده , , Y. and Matsui، نويسنده , , N. and Matsumoto، نويسنده , , H. and Matsunaga، نويسنده , , Deborah H. and Motoki، نويسنده , , M. and Nozaki، نويسنده , , M. and Nishihara، نويسنده , , Y. and Nishimura، نويسنده , , J. and Orito، نويسنده , , S. and Otoba، نويسنده , , M. J. Saeki، نويسنده , , T. and Sanuki، نويسنده , , T. and Sasaki، نويسنده , , M. and Shimamura، نويسنده , , K. and Suzuki، نويسنده , , J. and Suzuki، نويسنده , , K. and Takimi، نويسنده , , N. and Tanaka، نويسنده , , K. and Tsunoda، نويسنده , , T. and UEDA، نويسنده , , I. and Yajima، نويسنده , , T. and Yamagami، نويسنده , , T. and Yamamoto، نويسنده , , A. and Yamaoka، نويسنده , , H. and Yoshida، نويسنده , , T. and Yoshimura، نويسنده , , K.، نويسنده ,
Abstract :
The BESS detector is a new type of balloon-borne spectrometer which utilizes various technologies recently developed for collider experiments. The principal scientific objectives include a measurement of cosmic-ray antiproton spectrum, search for anti-nuclei in cosmic radiation, and precise meaurements of cosmic-ray primaries. A thin superconducting solenoidal coil produces a uniform magnetic field of 1 T. Cylindrical drift chambers are located inside and outside the coil and perform continuous tracking. The momentum resolution is 0.5% at 1 GeV/c. i.e., the maximum detectable rigidity is 200 GV. Scintillation counter hodoscopes, placed above and below the solenoid, provide timing and dE/dx measurements and trigger generation. The timing resolution is 80 ps/counter. This cylindrical configuration achieves a large geometrical acceptance of 0.35 m2 sr which is essential to detect rare cosmic-ray particles. In order to cope with high trigger rate and large data size, intelligent trigger circuits and a fast and parallel data acquision system are also developed. In 1993, the first scientific flight of the BESS apparatus was carried out and the first mass-measured antiprotons were detected at energies below 500 MeV
