Estimation of reliable range of electron temperature measurements with sets of given optical bandpass filters for KSTAR Thomson scattering system based on synthetic Thomson data

TL;DR

This paper assesses the reliability of electron temperature measurements in the KSTAR Thomson scattering system by using synthetic data to analyze the effects of optical filter transmittance on measurement accuracy.

Contribution

It introduces a forward model to evaluate measurement bias and errors, defining the reliable temperature measurement range for specific optical filters.

Findings

Reliable measurement range depends on filter transmittance and electron temperature.

Synthetic data can effectively quantify bias and random errors in measurements.

The method improves understanding of measurement limitations in Thomson scattering systems.

Abstract

One factor determining the reliability of measurements of electron temperature using a Thomson scattering (TS) system is transmittance of the optical bandpass filters in polychromators. We investigate the system performance as a function of electron temperature to determine reliable range of measurements for a given set of the optical bandpass filters. We show that such a reliability, i.e., both bias and random errors, can be obtained by building a forward model of the KSTAR TS system to generate synthetic TS data with the prescribed electron temperature and density profiles. The prescribed profiles are compared with the estimated ones to quantify both bias and random errors.