Temperature effects in the ATIC BGO calorimeter
J. Isbert, Louisiana State University
J. H. Adams, The University of Alabama in Huntsville
H. S. Ahn, University of Maryland, College Park
G. L. Bashindzhagyan, Lomonosov Moscow State University
K. E. Batkov, Lomonosov Moscow State University
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
T. G. Guzik, Louisiana State University
J. Chang, Max Planck Institute for Solar System Research
K. C. Kim, University of Maryland, College Park
E. N. Kouznetsov, Lomonosov Moscow State University
Z. W. Lin, Southern University and A&M College
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
John 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) Balloon Experiment had a successful test flight and a science flight in 2000-01 and 2002-03 and an unsuccessful launch in 2005-06 from McMurdo, Antarctica, returning 16 and 19 days of flight data. ATIC is designed to measure the spectra of cosmic rays (protons to iron). The instrument is composed of a Silicon matrix detector followed by a carbon target interleaved with scintillator tracking layers and a segmented BGO calorimeter composed of 320 individual crystals totaling 18 radiation lengths to determine the particle energy. BGO (Bismuth Germanate) is an inorganic scintillation crystal and its light output depends not only on the energy deposited by particles but also on the temperature of the crystal. The temperature of balloon instruments during flight is not constant due to sun angle variations as well as differences in albedo from the ground. The change in output for a given energy deposit in the crystals in response to temperature variations was determined. © 2007 COSPAR.
