Compact Soft X-Ray Microscopy

University dissertation from Stockholm : Fysik

Abstract: This thesis describes the development of soft x-rayreflective optics, instrumentation and applications for compactsoft x-ray microscopy. The microscope is based on a table-topliquid-jet-target laser-plasma source in combination with aspherical normal-incidence multilayer condenser mirror andnanofabricated diffractive optics for imaging. High-resolutionimaging is performed at the wavelength 3.374 nm in thewater-window (2.3 - 4.4 nm), where natural contrast betweencarbon and oxygen allows imaging of unstained biologicalmaterial in their natural aqueous environment.The design and implementation of a compact soft x-rayreflectometer based on a laser-plasma source is described. Thereflectometer allows rapid and accurate characterization ofnormal-incidence multilayer coatings used at water-windowwavelengths. This instrument, which measures absolutereflectivity and multilayer period, is now used in thefabrication process, aiming to improve the soft x-raynormal-incidence multilayer condenser system of the compactsoft x-ray microscope. Latest results from the developmentprocess are presented.A new design of the compact soft x-ray microscope, withimprovements in mechanical and thermal stability, providesuser-friendly and daily operation. This includes also a newnozzle design for the liquid-jet-target laser-plasma source,which enables higher source stability and operation withcryogenic liquids. In addition, a new experimental arrangementunder construction is briefly described. It will utilize acondenser zone plate and operate at the wavelength 2.478nm.Finally, performance test of the compact soft x-raymicroscope is presented and discussed. In addition, a projectto explore the use of soft x-ray microscopy for imaging sensorycells is described. The high-resolution imaging of these cellswas performed at the synchrotron-based soft x-ray microscope atLawrence Berkeley National Laboratory (LBNL).