The electron calorimeter (ECAL) long duration balloon experiment

T. G. Guzik, Louisiana State University
J. H. Adams, NASA Marshall Space Flight Center
G. Bashindzhagyan, Lomonosov Moscow State University
W. R. Binns, Washington University in St. Louis
J. Chang, Purple Mountain Observatory Chinese Academy of Sciences
M. L. Cherry, Louisiana State University
M. Christl, NASA Marshall Space Flight Center
P. Dowkontt, Washington University in St. Louis
B. Ellison, Louisiana State University
J. B. Isbert, Louisiana State University
M. H. Israel, Washington University in St. Louis
N. Korotkova, Lomonosov Moscow State University
M. Panasyuk, Lomonosov Moscow State University
A. Panov, Lomonosov Moscow State University
N. Sokolskaya, Lomonosov Moscow State University
M. Stewart, Louisiana State University
J. Watts, NASA Marshall Space Flight Center
J. P. Wefel, Louisiana State University
J. Wu, Purple Mountain Observatory Chinese Academy of Sciences
V. Zatsepin, Lomonosov Moscow State University

Abstract

Accurate measurements of the cosmic ray electron energy spectrum in the energy region 50 GeV to greater than 1 TeV may reveal structure caused by the annihilation of exotic dark matter particles and/or individual cosmic ray sources. Here we describe a new long duration balloon (LDB) experiment, ECAL, optimized to directly measure cosmic ray electrons up to several TeV. ECAL includes a double layer silicon matrix, a scintillating optical fiber track imager, a neutron detector and a fully active calorimeter to identify more than 90% of the incident electrons with an energy resolution of about 1.7% while misidentifying only 1 in 200,000 protons and 0.8% of secondary gamma rays as electrons. Two ECAL flights in Antarctica are planned for a total exposure of 50 days with the first flight anticipated for December 2009.