Table-top soft x-ray microscope using laser-induced plasma from a pulsed gas jet

Abstract

An extremely compact soft x-ray microscope operating in the "water window" region at the wavelength λ = 2.88 nm is presented, making use of a long-term stable and nearly debris-free laser-induced plasma from a pulsed nitrogen gas jet target. The well characterized soft x-ray radiation is focused by an ellipsoidal grazing incidence condenser mirror. Imaging of a sample onto a CCD camera is achieved with a Fresnel zone plate using magnifications up to 500x. The spatial resolution of the recorded microscopic images is about 100 nm as demonstrated for a Siemens star test pattern.

Radiation characteristics of extreme UV and soft X-ray sources

“…In particular, it facilitates the construction of a compact x-ray microscope with reasonable means [160]. Where so far, only sophisticated liquid targets resulted in acceptable exposure times, now a simple and clean target concept permits microscopic x-ray imaging at magnifications up to 500x within minutes.…”

Applications of a Compact "Water Window" Source for Investigations of Nanostructures Using SXR Microscope

“…A titanium filter (Lebow) allows to cut off H-like line almost completely, so the main part of the energy is in a single line (λ = 2.88 nm), in the "water window" spectral range [3][4][5][6].…”

Development and optimization of a “water window” microscope based on a gas-puff target laser-produced plasma source

“…Since the '90s, significant efforts were made to bring technical capabilities of synchrotron-based microscopes to the development of compact sources [1]- [8], because that the small size and versatility of compact microscopy system offers the possibility to perform imaging experiments, previously restricted to large-scale facilities, in university laboratories. It was already demonstrated that spatial resolution can be increased in nanoscale imaging systems employing short wavelength radiation such as soft X-ray (SXR) [9].…”