NEFERTARI WP5: a diagnostic neutral beam injector and spectroscopic diagnostics for RFX-mod2 core measurements

The ongoing upgrade of RFX-mod to RFX-mod2, thanks to a better stabilization of edge instabilities, will allow Consorzio RFX to continue experimental research on plasmas with Reversed Field Pinch and other magnetic confinement methods. To measure the ion temperature, the ion speed, the impurity content and the magnetic field in the plasma core, the Charge Exchange Recombination Spectroscopy (CXRS) and Motional Stark Effect (MSE) diagnostics require the injection of a neutral beam. The project NEFERTARI, with its Work Package 5, aimed at upgrading the RFX-mod diagnostic Neutral Beam Injector (DNBI), which could not be operated due to technical faults, to the obsolescence of several components and to high voltage safety issues. The open-cycle cryogenic pumping system was substituted with a commercial one, to ensure economic sustainability against helium costs. The duct between the DNBI and the toroidal chamber was redesigned and manufactured, to reduce beam reionization losses. Contemporarily, the CXRS and MSE diagnostics were designed and the main instrumentation was procured. This contribution presents an overview of the activities and of the results, with a focus on the new electric systems and control systems for the DNBI.