The Jem-Euso Mission

TL;DR

JEM-EUSO is a space-based observatory designed to detect ultra-high-energy cosmic rays via UV fluorescence, aiming to identify their sources and advance cosmic ray astronomy.

Contribution

This paper introduces the JEM-EUSO mission, a novel space instrument for observing extreme energy cosmic rays from the International Space Station.

Findings

Expected to detect over 1,000 events above 7x10^19 eV in five years

Will determine energy spectrum and source locations with high accuracy

Plans for deployment on the ISS in the early-to-mid 2010s

Abstract

JEM-EUSO is a space science mission to explore extreme energies and physics of the Universe. Its instrument will watch the dark-side of the earth and will detect UV photons emitted from the extensive air shower caused by an Ultra-High Energy Cosmic Rays (UHECRs above 10^18 eV), or Extremely High Energy Cosmic Ray (EHECR) particle (e.g., above about 10^20 eV). Such a high-rigidity particles as the latter arrives almost in a straight-line from its origin through the magnetic fields of our Milky Way Galaxy and is expected to allow us to trace the source location by its arrival direction. This nature can open the door to the new astronomy with charged particles. In its five years operation including the tilted mode, JEM-EUSO will detect at least 1,000 events with E>7x10^19 eV with the GZK cutoff spectrum. It can determine the energy spectrum and source locations of GZK to super-GZK regions with a statistical accuracy of several percent. JEM-EUSO is planned to be deployed by H2 Transfer Vehicle (HTV) and will be attached to the Japanese Experiment Module/ Exposure Facility (JEM/EF) of International Space Station. JAXA has selected JEM-EUSO as one of the mission candidates of the second phase utilization of JEM/EF for the launch in early-to-mid 2010s.