SPIDER, the Negative Ion Source Prototype for ITER: Overview of Operations and Cesium Injection

An overview of the recent operations and main results cesium injection in Source for Production Ions Deuterium Extracted from Rf plasma (SPIDER) negative ion source are described this contribution. In experiments without injection, all SPIDER plants were tested to verify basic expectations on operational parameters (e.g., electron cooling effectiveness magnetic filter field) determine its region. For beam properties, it was shown that current density varies across vertical direction. preliminary experiments, expected increase simultaneous decrease co-extracted electrons found, along with influence control (polarization electrodes, uniformity horizontal directions. It non-Gaussian tails can be identified angular distribution plane perpendicular propagation Stray particles, nonhomogeneous large divergence might result unexpected heat particle loads over ITER neutral injector (NBI) accelerator grids; is goal assess possibly identify suitable methods controlling these features. A major shutdown, planned late 2021, solve issues during operation carry out scheduled modifications, outlined. Such improvements allow pursue requirements terms current, electron-to-ion ratio, duration.