Numerical simulations of the plasma parameters in the SPIDER device

This paper presents the basic physical and numerical principles of a fluid model implemented into numerical code FSFS2D used for simulating the SPIDER negative ion source. It gives self-consistent 2D description of the source, including the neutral gas flow, plasma chemistry, RF coupling in the source driver and plasma transport through the magnetic filter. In order to capture the neutral depletion and its impact on the plasma dynamics the continuity equation for molecules is considered and the corresponding surface chemistry. A series of numerical simulations have been performed and results are compared to the experimental data from the SPIDER device. It appears, that in order to reproduce the experimental profiles of plasma parameters for the shot without magnetic filter on, it is anyway necessary to consider a low intensity (< 1 mT) of the magnetic field in the driver region.