HCN Laser Interferometer on the EAST Superconducting Tokamak

Abstract

A single-channel far-infrared (FIR) laser interferometer was developed to measure the line averaged electron density on the EAST tokamak. The structure of the single-channel FIR laser interferometer is described in detail. The evolution of density sawtooth oscillation was measured by means the FIR laser interferometer, and was identified by electron cyclotron emission (ECE) signals and soft X-ray intensity. The discharges with and without sawtooth were compared with each other in the Hugill diagram.