EXODUS: A new soft x-rays diagnostic system for tokamaks

The diagnosis of soft X-ray (SXR) emission from tokamaks represents a unique source of information, since it allows the study of several plasma parameters, such as the electron and ion temperature, the investigation of the ionization equilibrium, particle and runaway transport and the study of MHD fluctuations and disruptions. A new 2D-SXR diagnostic system called EXODUS (Enhanced X-ray Optimized Detector for Use in multiple Scenarios) has been developed with the aim to combine 2D energy resolved SXR emission profiles from the plasma with a high time (< 0.1 ms) and spatial resolution (< 3 mm2). The EXODUS system is based on the Gas Electron Multiplier (GEM) technology coupled with a padded anode readout and a new data acquisition system custom designed for GEM called GEMINI. In this contribution we will describe the laboratory characterization carried out on the first detector prototype using a quasi-monochromatic X-rays beam at very high rate (> 150 MHz) and the design of a enhanced version of the detector that is planned for installation on a tokamak in the near future. Preliminary measurements taken on plasma will be also shown.