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

TIGER experiment before launch in December 2003 in Antarctica. Note that an engineering model of the Antarctic Impulse Transient Antenna (ANITA) experiment was flown as a piggy back payload on TIGER

Flying in December 2012 Super-TIGER (Trans-Iron Galactic Element Recorder) is a new, large-area instrument being developed for flight on a high-altitude balloon over Antarctica to measure the elemental abundances of cosmic rays with atomic number Z in the interval 30≤Z≤42 with individual-element resolution and good statistical precision. It will test and clarify the emerging model of cosmic-ray origin in OB associations, and models for atomic processes by which nuclei are selected for acceleration. Super-TIGER is being developed by a collaboration of scientists from Washington University (PI Institution), Goddard Space Flight Center, Caltech/JPL, and the University of Minnesota and is funded by NASA.
 

Ultra-High-Energy
Cosmic Rays and Neutrinos

Garry Simburger and Dana Braun standing in front of the Antarctica Impulsive Transient Antenna (ANITA) gondola 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 2013. 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

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.