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We present the construction and the test of a generic neutrons detector for fusion experiments : OMEGA and NIF(USA), LMJ and APPOLON (FRANCE). The detector can be also used as a safety device on particle physics accelerator (ESS, Sweeden), Spiral2(France) etc.. . This detector is based on the technology CEA / IRFU MICROMEGAS detector. This diagnostic has been designed to achieve neutron spectroscopy in large γ background. Tests have been performed on the 60 beams, 30 kJ OMEGA laser system at the University of Rochester(LLE), and on LINAC4 accelerator at CERN during last november (Switzerland), and AMANDE(CEA). In Inertial Confinement Fusion experiment on facilities such as Laser MegaJoule (LMJ) in France and the National Ignition Facility (NIF) and OMEGA, LLE Rochester, USA we plan to achieve the ignition of capsules by compression deuterium-tritium (DT) or a deuteriumdeuterium (DD) filled target, and thus initiate a thermonuclear burn wave. In these experiments may be measured using neutrons output from the imploded capsule, like secondary and tertiary neutrons produced respectively in DD and DT targets. Measurement of these neutrons remains a challenge as the γ-rays and scattered neutrons induced by primary neutronsinteractions on the experimental hardware can blind detectors. The concept is based on the association of a Micromegas detector with a neutron-to-charged particle converter associated to a fast low noise electronics (

We have performed tests of Micromegas detector prototypes using the heavy-ion beams from the SIS synchrotron of GSI (Darmstadt, Germany). The beams varied from C 6 + 12 to Au 65 + 179 and from 250 to 1000 MeV per nucleon. We have tested two amplification technologies, conventional and resistive Micromegas, and two construction concepts, bulk-Micromegas and micro-meshes screwed on the PCB. The obtained position resolution below 200 μ m for 5 mm wide strips implies that the bulk resistive Micromegas technology might meet the requirements of the future R3B TPC project. We also developed a fast and very low noise front-end electronics connected directly to the Printed Circuit Board (PCB) of the detector itself. This concept has shown very good performances and robustness.