Improved gas-jet based extreme ultraviolet, soft X-ray laser plasma source

Abstract

We present a new nozzle design for an improved brilliance of laser-produced gas plasmas emitting in the soft X-ray and extreme ultraviolet spectral regime. A rotationally asymmetric gas jet is formed by employing two closely adjacent nozzles facing each other under the angle of 45°. The generated three-dimensional gas density distribution is tomographically analyzed using a Hartmann-Shack wavefront sensor. A comparison with numerical simulations accomplishes an optimization of the nozzle arrangement. The colliding gas jets create an optimized gas distribution with increased density, leading to a significant brilliance enhancement of the extreme ultraviolet, soft X-ray plasma.

High-Resolution Table-Top NEXAFS Spectroscopy

“…Several attempts in this direction have been undertaken, and in the hard X-ray range, lab-scale spectroscopy employing high-power X-ray tubes has already undergone tremendous development, accomplishing now routine investigations in commercial systems . Unfortunately, X-ray tubes are much less efficient in the soft X-ray range; however, in recent years considerable progress has also been made in this spectral region, benefitting from the development of laboratory-scale soft X-ray sources, using either laser- or discharge-produced plasmas − or high-order harmonics (HHG). − With the help of such sources, laboratory-scale NEXAFS spectroscopy has been successfully demonstrated, probing the K- and L- absorption edges of solid samples in the soft X-ray range up to ∼1.3 keV. − In contrast to NEXAFS spectroscopy at synchrotrons, where a highly monochromatic beam is spectrally scanned over the absorption edge of interest, lab-scale soft X-ray sources generally provide broad-band radiation, which is spectrally analyzed after transmission through a thin sample. Thus, these tools can acquire the entire absorption spectrum simultaneously.…”