THE JEM-EUSO MISSION

Abstract

The JEM-EUSO mission explores the origin of extreme energy cosmic rays (EECRs) above 50EeV and explores the limits of fundamental physics, through observations of their arrival directions and energies. It is designed to open a new particle astronomy channel. This super-wide-field (60 degrees) telescope with a diameter of about 2.5m looks down from space onto the night sky to detect near UV photons (330 ÷ 400nm, both fluorescent and Cherenkov photons) emitted from the giant air showers produced by EECRs. The arrival direction map with more than five hundred events will tell us the origin of the EECRs and will allow us to identify the nearest EECR sources with known astronomical objects. It will allow them to be examined in other astronomical channels. This is likely to lead to an understanding of the acceleration mechanisms, perhaps producing discoveries in astrophysics and/or fundamental physics. The comparison of the energy spectra among the spatially resolved individual sources will help to clarify the acceleration/emission mechanism, and also finally to confirm the Greisen-Zatsepin-Kuz'min process for the validation of Lorentz invariance up to 10 11 . Neutral components (neutrinos and gamma rays) can also be detected, if their fluxes are high enough. The JEM-EUSO mission is planned to be launched by a H2B rocket in about 2017 and transferred to ISS by the H2 Transfer Vehicle (HTV). It will be attached to the Exposed Facility external experiment platform of KIBO.