Observations of xenon spectra on the EAST x-ray crystal spectrometer for high-temperature plasma diagnostics

Abstract

The Xe44+ 2.7203Å, line, which is proposed as one of the diagnostic lines for the X-ray imaging crystal spectrometer on ITER, is observed on EAST tokamak together with its several satellite lines. The observations are made under high electron temperature (Te ) conditions (core Te > 5keV). Most of the observed xenon lines are identified by comparing the experiment results with the atmoic simulation results. The first ion temperature measurements made by the Xe spectra on EAST are also reported in this article. These xenon spectra observations contribute to the justification of using xenon as the diagnostic impurity of X-ray crystal spectrometers in future reactor-scale high-temperature plasmas.

X-ray Line-Intensity Ratios in Neon-like Xenon: Significantly Reducing the Discrepancy between Measurements and Simulations

“…According to our CRM simulation, in the ideal Maxwellian plasma where the EIE rates are calculated by convoluting σv (rate coefficient) with Maxwellian energy distribution function, the line-intensity ratio of 3F/3D remains constant at 0.526 ± 0.002 within this wide temperature range. This result theoretically indicates that the 3F/3D line-intensity ratio is insensitive to electron temperature, but it is inconsistent with the X-ray spectra for Ne-like Xe in EAST [9] and C-Mod tokamak [8]. The experimental 3F/3D ratios are clearly higher than above-mentioned theoretical value, especially at low electron temperature [8].…”

“…The identification of four weak lines was based on results from CRM simulations combined with previous measurements [9,16]. As shown in Figure 1, the experimental and theoretical spectra at 5.5 keV match well.…”

“…In tokamak plasma, Ne-like Xe reaches high concentration with an electron-temperature 4-10 keV [7,9]. According to our CRM simulation, in the ideal Maxwellian plasma where the EIE rates are calculated by convoluting σv (rate coefficient) with Maxwellian energy distribution function, the line-intensity ratio of 3F/3D remains constant at 0.526 ± 0.002 within this wide temperature range.…”

“…Its strong 3D {2p 6 -(2p 5 3/2 3d 5/2 ) J=1 , 2.7203 Å [6]} line serves as a valuable diagnostic tool in the core plasma [7]. Consequently, this ion has attracted considerable research attention, leading to extensive measurements in various experiments, including tokamaks [6,[8][9][10], EBITs [11][12][13][14][15][16][17], laser plasmas [18][19][20], and low-inductance spark devices [21]. Beyond the limitations of current diagnostic capabilities, the Ne-like Xe 44+ holds promise for an even broader diagnostic potential [22][23][24], thereby asking for more precise atomic parameters and sophisticated plasma models to refine spectral emission mechanisms.…”