Speaker
Prof.
John Wefel
(Louisiana State University)
Description
The Advanced Thin Ionization Calorimeter (ATIC) balloon experiment
traveled to McMurdo, Antarctica four times, resulting in three successful
circumpolar flights: ATIC-1, a test flight; ATIC-2, a science flight; ATIC-3, a
balloon failure; ATIC-4, the final science flight. In particular, ATIC-4 provided
the data to understand the discrepancy between the H, He spectra reported
from ATIC-1 and 2 (the ATIC-1 results are withdrawn) and allowed an increase
in calorimeter depth by 25%, thereby yielding improved measurements of the
cosmic ray electron spectrum. ATIC results revealed the hardening in the very
high energy H and He spectra, provided new measurements of the spectra of
the major heavy nuclei and demonstrated the existence of an excess of cosmic
ray electrons in the sub-TeV energy range. The ATIC flights and the ATIC
science results are discussed in the context of other recent measurements and
astrophysical models.
Primary author
Prof.
John Wefel
(Louisiana State University)
