page_title: Cosmic Ray Energetics and Mass Experiment
section_title: Expected outcomes
hierarchical_section_title: Cosmic Ray Energetics and Mass Experiment / Expected outcomes
caption_attribution_description: English: CREAM III takes flight in Antarctica
context_page_description: Cosmic Ray Energetics and Mass is an experiment to determine the composition of cosmic rays up to the 10¹⁵ eV in the cosmic ray spectrum.
  It has been hypothesized that the knee prospect of the cosmic ray spectrum can be explained by the theoretical maximum energy that a supernova can accelerate particles to according to Fermi acceleration. The measurements are accomplished using a timing-based charge detector and transition radiation detector sent to an altitude of at least 34 km with aid of a high-altitude balloon.
  After launching from McMurdo Station in Antarctica, the balloon will stay aloft for 60–100 days gathering data on charges and energies of the unimpeded cosmic rays that strike the detectors.
context_section_description: One of the advantages of this type of experiment is that it is possible to identify the original particle that would have caused the air shower detected by ground-based detectors. Maximum detectable energy level is determined by duration of the flight and size of the detector; a difficult barrier to get around for experiments of this type. An accurate measurement of the composition of cosmic rays is necessary in order to understand the origins of the cosmic rays found above the "knee" at 10¹⁵ eV. To date, the CREAM balloon experiments have accumulated a total of 161 days of exposure, longer than any other single balloon-borne experiment.
caption: CREAM III takes flight in Antarctica
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