The Transition Radiation Array for Cosmic Energetic Radiation
(TRACER) is a new instrument for direct, balloon borne
measurements of single element heavy cosmic ray nuclei (boron to iron) in the
energy range from 1013 to several 1015 eV per nucleus.
TRACER recently completed its third flight, making a four and a half day journey from Kiruna, Sweden to Sommerset Island, Canada.
Improvements to TRACER for this flight
are the extension of the dynamic range of the Transition Radiation
Detector to include Boron and Carbon and the addition of a second Cerenkov Counter to increase Charge
Tracer launch, Kiruna Sweden
Days after the conclusion of its third flight, an intact TRACER was successfully recovered from Somerset Island, Canada.
In 2003 TRACER had a successful 14 day Antarctic flight,
traversing some 5,000 miles around the South Pole at an average
elevation of 125,000 ft. TRACER sampled over 50 Million
heavy Cosmic Rays during the 2003 flight (Carbon through Iron). Results from this flight are
available on our results page and have been presented at conferences including the 2005 APS, ICRC and TRD workshop and the 2006 COSPAR conference..
Preliminary results from TRACER's 2006 flight
The individual energy spectra of heavy cosmic rays are poorly
known above a TeV/nucleon. At these energies cosmic rays carry
an important imprint of the acceleration and propagation
mechanisms allowing one to probe possible sources of these
cosmic rays. By increasing our knowledge at higher energies we
are able to overlap with measurements from the ground to allow a
better understanding of airshower development.
The Transition Radiation Array for
Cosmic Energetic Radiation (TRACER) is a new instrument for
direct, balloon borne measurements of heavy cosmic ray nuclei
(boron to iron) in the energy range from 1013 to
several 1015 eV per nucleus.
The instrument has been developed and constructed at the
University of Chicago
under support from NASA.
Antarctic LDB Mission 2003
TRACER was designed to fly on a long duration balloon (LDB)
around the poles. The instrument is suspended below a 40
million cubic balloon filled with Helium. Once launched the
balloon will rise to an altitude of 125,000ft (above 99% of the
atmosphere) for a period of 14 - 30 days. By climbing above the
atmosphere one tries to sample the cosmic rays before they are
destroyed by interactions with the atmosphere. For more on the science of TRACER, see the results section.
TRACER Launch (12/12/03)