2D–4D Simulations of Neutral Particles Penetration into Central Plasma Region in the L-2M Stellarator. Verification of Results Using ASTRA Code

The 2D code developed by the authors for calculating the penetration of neutral particles from the chamber wall to the center of the plasma created and confined in the L-2M stellarator has been verified. In the range of operating plasma densities (1 × 10¹⁹ m^–3 < n_e < 3 × 10¹⁹ m^–3), good agreement with the results of calculations performed using the ASTRA code has been obtained. The 3D and 4D simulations of the penetration of neutral particles from the chamber wall to the central plasma region have been performed. It has been shown that the 2D simulations overestimate the concentration of neutral particles in the plasma central region, as compared to the 3D and 4D models, which use ion velocity distributions closer to the real one.