Simulation Study of Ultrashort-Pulse Reflectometry by Signal Record Analysis

Abstract

Reflectometry is expected to be come one of the key diagnostic tools for measuring density profiles in large fusion devices. It provides good spatial and temporal resolutions, while requires only a single viewing chord and minimal vacuum access, in contrast to interferometry and Thomson scattering. We applied an ultrashort-pulse reflectometer (USPR) to Large Helical Device (LHD) at the National Institute for Fusion Science (NIFS), and a signal record analysis (SRA) method was used as a reconstruction method. Here, we report a simulation study of USPR conducted using a finite-difference time domain (FDTD) method to confirm the effectiveness of the SRA reconstruction method.