Two-Dimensional Distribution of Plasma Electric Potential in the T-10 Tokamak

Heavy ion beam probe (HIBP) is a unique plasma diagnostics that makes it possible to measure the electric potential φ of high-temperature plasma and its fluctuations φ̃ , as well as the density ñ_e and poloidal magnetic field B̃_pol fluctuations. Position of the point of performing measurements in the plasma vertical cross-section depends on the beam energy and angle of its entrance into the plasma. The variation of these two parameters makes it possible to construct a two-dimensional (2D) detector grid, which covers the domain of possible measurements. The measurement results obtained in the detector grid points provide for constructing 2D distributions of plasma parameters. For the OH and ECRH stages of the T-10 tokamak shots, 2D distributions of the plasma electric potential are presented for the regime with the on-axis magnetic field of B t = 2.2 T, plasma current of I pl = 230 kA, line-average density of n̅_e ≈ 1.1 × 10 19 m –3 and off-axis ECRH power of P ECRH = 1.7 MW.