The Spectrum of Ion Cyclotron Emission from Neutral Beam Injection Heated Plasma on the TUMAN-3M Tokamak

Abstract

Radiation at the ion cyclotron resonance frequencies in both the ohmic mode and the injection heating mode—ion cyclotron emission (ICE)—is observed on the TUMAN-3M tokamak (minor radius a = 0.25 m, major radius R₀ = 0.5 m, toroidal field B_T = 1 T, plasma current I_p ≤ 180 kA, and average plasma electron density n_e ≤ 5 × 10¹⁹ m^–3). Usually, the ICE is associated with the presence of high-energy ions in the plasma. Such ions may be products of a thermonuclear reaction or arise as a result of additional plasma heating, e.g., by means of electromagnetic waves or by injection of beams of high-energy atoms (neutral beam injection, NBI). The properties of the ICE in the TUMAN-3M tokamak in the NBI-heating mode and their possible connection with the features of fast ion trajectories and their energy spectrum are considered.