Design and optimization of a soft X-ray tomography system on Keda Torus eXperiment

Abstract We report about the soft X-ray (SXR) tomography system which is being developed on Keda Torus eXperiment (KTX). The tomographic system aims at studying three dimensional effects in reversed field pinch with high plasma current, particularly in quasi-single-helicity state (QSH). The view distribution of the probes has been carefully designed to reflect the experimental constraints. Bayesian experimental design (BED) is used to optimize the signal camera location and camera opening angle, aiming at maximizing the gain information in future QSH states. The BED approach allows us to quantitatively evaluate the performance of the design, and to estimate the design robustness. The physical image of the plasma is tomographically reconstructed using Cormack approach and the reconstructed emissivity image may be compared to the emissivity model using the residual error χ. The camera location, camera opening angle, and sightline density are finally decided by quantitatively comparing diverse designs in order to achieve the best reconstruction.