Electronic temperatures, densities, and plasma x-ray emission of a 14.5 GHz electron-cyclotron resonance ion source

Abstract

We have performed a systematic study of the Bremsstrahlung emission from the electrons in the plasma of a commercial 14.5 GHz Electron-Cyclotron Resonance Ion Source. The electronic spectral temperature and the product of ionic and electronic densities of the plasma are measured by analyzing the Bremsstrahlung spectra recorded for several rare gases (Ar, Kr, Xe) as a function of the injected power. Within our uncertainty, we find an average temperature of ≈ 48 keV above 100W, with a weak dependency on the injected power and gas composition. Charge state distributions of extracted ion beams have been determined as well, providing a way to disentangle the ionic density from the electronic density. Moreover X-ray emission from highly charged argon ions in the plasma has been observed with a high-resolution mosaic crystal spectrometer, demonstrating the feasibility for high-precision measurements of transition energies of highly charged ions, in particular of the magnetic dipole (M1) transition of He-like of argon ions.

Experimental Characterization of an Overdense Plasma in a Compact Ion Source

“…Analyses of the Bremsstrahlung spectrum generated by electrons when colliding with the other plasma particles provide a tool for diagnosing high temperature electrons [14,15]. In general, if the X-ray spectrum is known, it is possible to find the electron density and the temperature of the plasma that generated it [14].…”

X-ray-spectroscopy analysis of electron-cyclotron-resonance ion-source plasmas

“…The electron distribution function f (E) is strongly non-Maxwellian and can be represented by two populations [13]: a cold one (energies up to 10 keV) and a hot one (energies of several tens of keV); the latter is well confined inside a closed egg-shaped surface centered around the source main axis. Barué et al [13] and Gumberidze et al [5] studied experimentally the energy distribution of the hot electrons observing bremsstrahlung and electron cyclotron emission.…”

“…Their plasmas are also more and more used as powerful sources of radiation, whether to provide vacuum-ultraviolet radiation sources [1] or intense sources of highly charged ion x rays [2,3]. The radiation emitted by the ions in the plasma can be used for plasma diagnostic [4,5], for spectrometer characterization [6], and to provide accurate transition energies of highly charged ions.…”

The Lattice Spacing Variability of Intrinsic Float-Zone Silicon

“…The DCS was designed and built to operate in vacuum and to be attached to an Electron Cyclotron Resonance Ion Source (ECRIS) to directly observe the highly charged ion plasma [42]. The DCS described in [9], in addition to providing reference-free line energy measurements with a relative , can also be a tool to determine transition probabilities and ion temperatures inside a highly charged ion plasma [43].…”