Elemental Spectra from the CREAM-I Flight

• Main Authors: Ahn, H.S., Allison, P.S., Bagliesi, M.G., Beatty, J.J., Bigongiari, G., Boyle, P., Childers, J.T., Conklin, N.B., Coutu, S., DuVernois, M.A., Ganel, O., Han, J.H., Jeon, J.A., Kim, K.C., Lee, J.K., Lee, M.H., Lutz, L., Maestro, P., Malinin, A., Marrocchesi, P.S., Minnick, S.A., Mognet, S.I., Nam, S.W., Nutter, S.L., Park, I.H., Park, N.H., Seo, E.S., Sina, R., Swordy, S., Wakely, S., Swordy, S.P., Wakely, S.P., Wu, J., Yang, J., Yoon, Y.S., Zei, R., Zinn, S.Y.
• Language: English
• Published: 2010
• Subjects: Astrophysics and Astronomy; Antarc*; Antarctica
• Online Access: http://cds.cern.ch/record/1255645

The Cosmic Ray Energetics And Mass (CREAM) is a balloon-borne experiment designed to measure the composition and energy spectra of cosmic rays of charge Z = 1 to 26 up to an energy of ~ 10^15 eV. CREAM had two successful flights on long-duration balloons (LDB) launched from Mc- Murdo Station, Antarctica, in December 2004 and December 2005. CREAM-I achieves a substantial measurement redundancy by employing multiple detector systems, namely a Timing Charge Detector and a Silicon Charge Detector (SCD) for particle identification, and a Transition Radiation Detector and a sampling tungsten/scintillating-fiber ionization calorimeter (CAL) for energy measurement. In this paper, preliminary energy spectra of various elements measured with CAL/SCD during the first 42-day flight are presented. The Cosmic Ray Energetics And Mass (CREAM) is a balloon-borne experiment designed to measure the composition and energy spectra of cosmic rays of charge Z = 1 to 26 up to an energy of ~ 10^15 eV. CREAM had two successful flights on long-duration balloons (LDB) launched from Mc- Murdo Station, Antarctica, in December 2004 and December 2005. CREAM-I achieves a substantial measurement redundancy by employing multiple detector systems, namely a Timing Charge Detector and a Silicon Charge Detector (SCD) for particle identification, and a Transition Radiation Detector and a sampling tungsten/scintillating-fiber ionization calorimeter (CAL) for energy measurement. In this paper, preliminary energy spectra of various elements measured with CAL/SCD during the first 42-day flight are presented. The use of detectors based on plastic scintillator with photomultiplier tubes (PMTs) is common in cosmic-ray experiments to differentiate particle charges. However, in the presence of a calorimeter, the standard method of pulse charge integration over a time longer than a PMT pulse is hampered by abundant albedo particles. The Cosmic Ray Energetics and Mass (CREAM) instrument surmounts this problem by measuring the peak voltage of the PMT pulse ...