Cosmic Ray Group:
  1. Experimental measurements of the elemental and isotopic composition of heavy cosmic rays
  2. Experimental measurements of ultra-high energy cosmic rays and neutrinos.

Elemental Composition of
Galactic Cosmic Rays

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SuperTIGER instrument preparing for launch in December 2012 in Antarctica.
The SuperTIGER (Super Trans-Iron Galactic Element Recorder) measures the elemental composition of ultra-heavy galactic cosmic-ray (UHGCR) nuclei with charge (Z) 26 <= Z <= 40 with high statistical precision and excellent charge resolution and makes exploratory measurements into the 40 < Z <= 60 range. SuperTIGER had a record breaking 55-day balloon flight over Antarctica in December 2012 – January 2013. Data collected from this flight is testing and clarifying the emerging model of cosmic-ray origin in OB associations and models for atomic processes by which nuclei are selected for acceleration. SuperTIGER is a collaboration of scientists from Washington University (PI Institution), Goddard Space Flight Center, Caltech/JPL, and the University of Minnesota.
 

Ultra-High-Energy
Cosmic Rays and Neutrinos

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Garry Simburger and Dana Braun standing in front of the Antarctica Impulsive Transient Antenna (ANITA) which is used to investigate high-energy neutrinos and the origin of galactic cosmic-ray nuclei.
The Antarctic Impulsive Transient Antenna (ANITA) instrument is designed to measure the energy spectrum of ultra-high energy cosmic rays (UHECRs) and neutrinos with energies > 1018 eV. It has been flown twice on high-altitude balloons over Antarctica. From data obtained on these flights we have obtained an upper-limit on the high-energy neutrino abundance for E>1018 eV and discovered a new modality for the detection of UHECRs based on synchrotron emission . The instrument is being optimized for the detection of UHECRs on the planned flight of ANITA-3 over Antarctica in December 2014. The PI institution for this experiment is the University of Hawaii. The experiment is being performed by a collaboration of experimenters from a number of universities. For more details go to the ANITA website.

Isotopic Composition of
Galactic Cosmic Rays

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The Advanced Composition Explorer (ACE) spacecraft before launch in 1997. The Cosmic Ray Isotope Spectrometer instrument (CRIS) is mounted on the side of the spacecraft.

The Cosmic Ray Isotope Spectrometer (CRIS), which is aboard the NASA Advanced Composition Explorer (ACE) spacecraft, is designed to measure the elemental and isotopic abundances of galactic cosmic rays heavier than Lithium. These measurements enable us to obtain source abundances and energy spectra (~50 to 600 MeV/nucleon) for the primary nuclei. ACE was launched in 1997 into an orbit around the L1 libration point which is outside the Earth’s magnetosphere. The CRIS experiment continues to return excellent quality data. Ongoing work at Washington University is aimed at measuring the elemental and isotopic abundances of elements heavier than Copper and studying models of cosmic-ray propagation that will enable us to obtain source abundances. This research is being conducted by a collaboration of scientists from Caltech (PI Institution), the Jet Propulsion Laboratory, Goddard Space Flight Center, and Washington University. For more details go to the ACE website.