Theoretical Modeling of High-Resolution X-ray Spectra Emitted by Tungsten and Molybdenum Ions from Tokamak Plasmas

Ł Syrocki,E Węder,K Słabkowska,M Polasik,J Rzadkiewicz

doi:10.1007/s10894-020-00231-y

Ł Syrocki, E Węder + Show 3 more

Open Access

https://doi.org/10.1007/s10894-020-00231-y

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Abstract

In order to allow the advanced interpretation of the X-ray spectra registered by the high-resolution crystal KX1 spectrometer on the JET with an ITER-like wall, especially to determine how the relative emission contributions of tungsten and molybdenum ions change during a JET discharge, the X-ray spectra have been carefully modeled over a narrow wavelength range. The simulations have been done in the framework of Collisional–Radiative model implemented in Flexible Atomic Code for an electron density (ne = 2.5 × 1019 m−3), and electron temperatures between Te = 3.0 keV and Te = 4.5 keV, typical for JET. Moreover, performed detailed analysis in the framework of the proposed procedure can be useful in determining temperature of a high temperature plasma generated in tokamaks.

Highlights

The hot, low density plasma in a tokamak such as JET emits a very complex radiation spectrum over a wide range of photon energies; qualitatively the same is expected from the future thermonuclear reactor ITER
In order to allow the advanced interpretation of the X-ray spectra registered by the high-resolution crystal KX1 spectrometer on the JET with an ITER-like wall, especially to determine how the relative emission contributions of tungsten and molybdenum ions change during a JET discharge, the X-ray spectra have been carefully modeled over a narrow wavelength range
Performed detailed analysis in the framework of the proposed procedure can be useful in determining temperature of a high temperature plasma generated in tokamaks

Summary

Introduction

The hot, low density plasma in a tokamak such as JET emits a very complex radiation spectrum over a wide range of photon energies; qualitatively the same is expected from the future thermonuclear reactor ITER. This paper shows how to determine the emission contributions from tungsten and molybdenum ions in X-ray spectra measured, in the specific wavelength region covered by the high-resolution crystal spectrometer KX1, which is local, JET specific assignment for the plasma parameters diagnostic [9,10,11,12,13,14]. 2p transitions that happen to fall right in between those of the M shell X-rays from Cu-like and Ni-like tungsten ions, a coincidence that offers a way to determine how much molybdenum is present in the JET plasma This is done by creating a data base of spectral shapes, selection of relevant plasma parameters, and interpreting high-resolution X-ray spectra in terms of these parameters. Determination of the Contributions from Tungsten and Molybdenum Ions by Interpretation of the High Resolution X-ray Spectra Registered on JET: Stage II.

Summary

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