CALET: Flight Operations and Data Analysis

Multiple-Institution Proposal: NNH14ZDA001N-APRA, ROSES-2014 NRA CALET: Flight Operations and Data Analysis University of Denver Co-I Background CALET is an experiment to study cosmic ray electrons, gamma-rays and nucleons in the energy range up to 10 TeV. This proposal is the University of Denver portion of a multi-institution proposal for US involvement in the flight operations and data analysis. The experiment has been built by Prof. Shoji Torri, Waseda University in Tokyo, and other collaborators in Japan. The experiment uses an imaging Calorimetric Electron Telescope (CALET) and will be launched later this year to be mounted on the Japanese Experiment Module (JEM) on the International Space Station (ISS). The Principal Investigator of the effort in the United States is Dr. John Wefel, Professor of Physics at Louisiana State University. This is a proposal to LSU for the University of Denver to participate in this effort. Other astroparticle physicists proposing are from the Goddard Space Flight Center and Washington University in St. Louis. Scientific motivation Matter accelerated to velocities very close to the speed of light and originating external to our solar system has been studied at Earth for more than 100 years. Known as cosmic rays, the sites of the origin of these particles and the mechanism of their acceleration are not yet completely understood. In particular, recent data from gamma-rays at TeV energies and x-ray studies of particle acceleration associated with shocks in supernova remnants (SNR) appears to establish diffusive shock acceleration as the best explanation for how galactic cosmic rays (GCR) below 3 x 10^15 eV (the ‘knee’ in the all particle spectrum) achieve their high energies. Alternate explanations involve mechanisms in which repeated supernova that carve superbubbles in the interstellar medium may be required. However the spectral signatures predicted by this model have not yet been observed, and no direct detection of accelerated particles from a specific source has yet been achieved. Cosmic ray transport through the galaxy is understood to also be a diffusion process, where the hadronic components of the GCR may traverse the distance equivalent of hundreds of galactic diameters during their lifetime, thereby randomizing their trajectory and losing connection with their original source. High-energy electrons, however, have radiative energy loses that limit their lifetime and, consequently, the distance they can diffuse away from their source. As a result, the highest energy GCR electrons that we see at Earth very likely originate from sources younger that 105 years and less than 1 kpc from the Solar System (Kobayashi et al., 2004). A handful of candidate SNRs that meet these requirements have been identified by the Fermi gamma-ray telescope. The GCR electron energy spectrum at energies above 1 TeV should show structure and evidence anisotropy (Ptuskin and Ormes, 1995) allowing these energetic particles to be associated with a specific source. Dr. Ormes specific efforts will include: Year 1: Dr. Ormes will serve as a senior scientific advisor to the analysis teams, reviewing and commenting on operational and data analysis plans. Year 2: Dr. Ormes will serve as a senior scientific advisor to the analysis teams, reviewing and commenting on ongoing operations and data analysis methods. Year 3: Dr. Ormes will serve as a senior scientific advisor to the analysis teams, reviewing and commenting on ongoing operations and data analysis results and review of publications. Year 4: Dr. Ormes will serve as a senior scientific advisor to the analysis teams, reviewing and commenting on ongoing operations and data analysis results and review of publications. More »