Line identification of extreme ultraviolet spectra from aluminum ions in EAST Tokamak plasmas

TL;DR

This study identifies and analyzes EUV spectral lines from aluminum ions in EAST Tokamak plasmas using advanced spectrometry and multiple atomic structure calculation codes, improving line identification accuracy.

Contribution

It introduces a multi-code approach for accurate spectral line identification of aluminum ions in tokamak plasmas, enhancing atomic data validation.

Findings

Successful observation of multiple aluminum ion spectral lines

Use of three independent codes to resolve line ambiguities

Validation of theoretical predictions with experimental data

Abstract

Extreme ultraviolet (EUV) spectra emitted from aluminum in the 5-340 A wavelength range were observed in Experimental Advanced Superconducting Tokamak (EAST) discharges. Several spectral lines from aluminum ions with different degrees of ionization were successfully observed with sufficient spectral intensities and resolutions using three fast-time-response EUV spectrometers. The line identification uses three independent state-of-art computational codes for the atomic structure calculations, which provide the wavelengths and radiative transition probabilities rate coefficients. These programs are HULLAC (Hebrew University - Lawrence Livermore Atomic Code), AUTOSTRUCTURE, and FAC (Flexible Atomic Code). Using three different codes allows us to resolve some ambiguities in identifying certain spectral lines and assess the validity of the theoretical predictions.