Plasma radiation losses and particle transport on the Globus-M tokamak*

In this work the results of investigation of plasma radiation losses by means of a tomography diagnostic system are presented. The system is based on a 16×16 tangential matrix array and a 24×1 linear array of silicon photodiodes. Presented are the dependence of plasma radiation losses on plasma current, toroidal magnetic field and heating regime for a range of electron densities. Transport properties of the main plasma impurity, carbon, were analyzed using ASTRA and STRAHL codes by matching modelled and experimental plasma emissivity profiles and loop voltages. The 16×16 matrix array was used to explore the penetration of hydrogen and helium jets in the tokamak plasmas. Injection of the hydrogen jet led to the two-fold increase in the core electron density. In the experiments, it was observed that the velocities of the jets decreased exponentially with the characteristic times corresponding to the deceleration mechanism due to the Alfvén conductivity.