Laboratory-Scale Soft X-ray Source for Microscopy and Absorption Spectroscopy

Abstract

Soft X-ray microscopy and absorption spectroscopy are extremely useful tools for high-resolution imaging and chemical analysis of samples in various scientific fields. However, due to the required high photon flux of soft X-ray radiation, up to now, both methods are almost exclusively performed at synchrotron sources. Thus, great efforts have been made to develop table-top sources emitting in the soft X-ray spectral range ($$\lambda =$$ λ = 1–5 nm). Here, the development of a laser-produced plasma source from a pulsed gas jet is presented, enabling the construction of an almost debris-free, compact and long-term stable X-ray source. Based on this source a compact soft X-ray microscope (spatial resolution 50 nm) operating at a wavelength of $$\lambda = 2.88$$ λ = 2.88 nm was built and applied for imaging of various test and biological objects. In addition, a laboratory-scale NEXAFS spectrometer has been established, allowing for reliable analysis of different absorption edges at photon energies between 250 and 1250 eV.

Table-Top Water-Window Microscope Using a Capillary Discharge Plasma Source with Spatial Resolution 75 nm

“…In recent years, considerable progress has been achieved, and several transmission SXR microscopes operating in the water-window region based on table-top sources were reported. Compact transmission SXR microscopic systems based on laser-produced plasma sources-using liquid-jet target [8][9][10], gaseous target [11,12], double-stream gas target [13][14][15], or ultra-thin metal target [16]-were developed. The second branch of laboratory-scale transmission SXR microscopes are based on discharge-produced plasma sources using pseudo sparks such as electrode geometry [17], an electrode-less design (Energetiq, Inc., WI, MA, USA) [18,19], or Z-pinching capillary discharge [20].…”