A compact electron beam ion trap in support of high-temperature plasma diagnostics based on conduction-cooled superconducting coils

Spectroscopic diagnostics of future fusion reactor plasmas require information on impurity line emissions, especially for relevant high-Z metal elements (e.g., tungsten). These materials will be widely used as plasma facing components for their high heat tolerance and low sputtering yield. Based on an electron beam ion trap, a compact impurity spectra platform is developed to mimic the high-temperature environment of a fusion reactor. The proposed platform can deliver a focused e-beam at energies over 30 keV using a confining magnetic field of similar to 1.0 T generated by two superconducting coils (NbTi). Cooled by a closed-loop cryocooler, the coils can avoid the usage of a complicated cryogenic system involving the handling of liquid helium. For spectroscopic studies of highly charged ions, a spherically curved crystal spectrometer is proposed to measure a wavelength range around 2-4 angstrom covering the typical wavelength range expected to be emitted by metal ions in a fusion plasma. This paper reports the design and development progress of the platform. Published under an exclusive license by AIP Publishing.

Automated summary

The spectroscopic diagnostics of future fusion reactor plasmas require information on impurity line emissions, especially for high-Z metal elements like tungsten. A compact impurity spectra platform has been developed to mimic the high-temperature environment using an electron beam ion trap, confining magnetic field, and spherically curved crystal spectrometer. This platform can deliver a focused e-beam at energies over 30 keV and measure a wavelength range around 2-4 angstrom for spectroscopic studies of highly charged ions.