The JEM-EUSO Global Light System
Abstract
The Global Light System (GLS) is a network of ground-based Xenon flashlamps and steered UV lasers to validate the key functions of the JEM-EUSO cosmic ray fluorescence detector that is planned for the international space station. These functions include triggering efficiency, the accuracy of intrinsic luminosity measurements, and the reconstructed pointing direction accuracy. GLS units will generate benchmark optical signatures in the atmosphere with similar characteristics to the optical signals of cosmic ray EASs. The lasers will generate tracks and the flashers will generate point flashes. But unlike air showers, the number of laser and flasher pulses, their energy, precise time, direction (lasers) can be specified. JEM-EUSO will reconstruct the pointing directions of the lasers and the energy of the lasers and flashlamps to monitor the detector triggers, and accuracy of energy and direction reconstruction. 12 GLS units will be deployed at selected sites around the globe. The JEMEUSO footprint will pass over a GLS unit on average once per (near) moonless night under clear conditions for appropriately selected sites. The 12 units will be supplemented by campaign style measurements with an airborne unit that will be flown over the open ocean at selected altitudes under JEM-EUSO. A GLS prototype in an airplane will support a high-altitude balloon flight in 2014 of a prototype JEM-EUSO telescope. We describe the concept and system design and report on the status of prototyping and the selection process for candidates sites.
- Publication:
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International Cosmic Ray Conference
- Pub Date:
- 2013
- Bibcode:
- 2013ICRC...33.2117W
- Keywords:
-
- JEM-EUSO;
- air showers;
- atmosphere;
- flashlamps;
- lasers;
- calibration;
- International Space Station.