Status of the JEM EUSO telescope on International Space Station

Abstract JEM-EUSO is a large telescope looking at the earth from the ISS. It uses a huge volume of the earth's night sky atmosphere in which an extremely energetic cosmic ray particle ( E > 10 19 eV ) generates a straight-line N2 fluorescence signal on the path of the cascade shower moving at the speed of light for a length of 10–100 km depending on the incident angle. The space–time resolved calorimetry of showers is achieved with a large-aperture Fresnel lens optics and a large-area focal surface of detectors. Such a system in space is capable of detecting thousands of events with energy above 10 20  eV ( > 1000 super-LHC) in a few years of operation on orbit, allowing a particle channel of astronomy and for research of fundamental physics in the universe. Neutrino interaction cross-sections at such high energies are expected to increase in the Standard Model, and EUSO expects a reasonable chance of observing the cosmogenic neutrino events among those detectable showers, because the atmospheric target mass of the EUSO TPC exceeds 1 trillion tons. This experiment JEM-EUSO is currently considered by the Japan Aerospace Exploration Agency (JAXA) for a possible payload on the Japan Experiment Module (JEM) of the International Space Station (ISS).