Cosmic Ray Energetics and Mass (CREAM)
The Cosmic Ray Energetics and Mass (CREAM) experiment was designed and constructed to measure cosmic ray elemental spectra using a series of long duration balloon flights around the south pole in Antarctica. It is a cooperative effort of the University of Maryland, Pennsylvania State University, Northern Kentucky University and NASA Goddard Space Flight Center from USA, Ewha Woman's University from Korea, LPSC Grenoble and CESR Toulouse of France and finally UNAM from Mexico.
The goal of the experiment is to extend direct measurement of cosmic-ray composition to the energies capable of generating gigantic air showers which have been mainly observed on the ground, thereby providing calibration for indirect measurements. The instrument has redundant and complementary charge identification and energy measurement systems capable of precise measurements of elemental spectra for Z = 1 - 26 nuclei over the energy range ~1011 to 1015 eV. Precise measurements of the energy dependance of elemetal spectra at the highest of these energies, where the rigidity-dependant supernova acceleration limit could be reflected in a composition change, provide a key to understanding cosmic ray acceleration and propogation. The instrument includes a Timing Charge Detector (TCD), a Cherenkov Detector (CD), a Transition Radiation Detector (TRD), a Cherenkov Camera (CherCam), a Silicon Charge Detector (SCD), scintillating fiber hodoscopes, and a tungsten-scintillating fiber calorimeter.
The CREAM mission has had six successful flights with different detector configurations between 2004 and 2010. A total cumulative exposure of ~162 days has been achieved.