Enhancing the ATIC charge resolution

T. G. Guzik, Louisiana State University
J. H. Adams, NASA Marshall Space Flight Center
H. S. Ahn, University of Maryland, College Park
G. L. Bashindzhagyan, Lomonosov Moscow State University
K. E. Batkov, Lomonosov Moscow State University
J. Chang, Purple Mountain Observatory Chinese Academy of Sciences
M. Christl, NASA Marshall Space Flight Center
A. R. Fazely, Southern University and A&M College
O. Ganel, University of Maryland, College Park
R. M. Gunashingha, Southern University and A&M College
J. Isbert, Louisiana State University
K. C. Kim, University of Maryland, College Park
E. N. Kouznetsov, Lomonosov Moscow State University
M. I. Panasyuk, Lomonosov Moscow State University
A. D. Panov, Lomonosov Moscow State University
W. K.H. Schmidt, Max Planck Institute for Solar System Research
E. S. Seo, University of Maryland, College Park
N. V. Sokolskaya, Lomonosov Moscow State University
J. W. Watts, NASA Marshall Space Flight Center
J. P. Wefel, Louisiana State University
J. Wu, University of Maryland, College Park
V. I. Zatsepin, Lomonosov Moscow State University

Abstract

The Advanced Thin Ionization Calorimeter (ATIC) experiment is designed to investigate the charge composition and energy spectra of primary cosmic rays over the energy range from about 10 11 to 10 14 eV during Long Duration Balloon (LDB) flights from McMurdo, Antarctica. Currently, analysis from the ATIC-1 test flight and ATIC-2 science flight is underway and preparation for a second science flight is in progress. Charge identification of the incident cosmic ray is accomplished, primarily, by a pixilated Silicon Matrix detector located at the very top of the instrument. While it has been shown that the Silicon Matrix detector provides good charge identification even in the presence of electromagnetic shower backscatter from the calorimeter, the detector only measures the charge once. In this paper, we examine use of the top scintillator hodoscope detector to provide a second measure of the cosmic ray charge and, thus, improve the ATIC charge identification. © 2007 COSPAR.