This application discloses an x-ray interferometric imaging system in which the x-ray source comprises a target having a plurality of structured coherent sub-sources of x-rays embedded in a thermally conducting substrate. The system additionally comprises a beam-splitting grating G1 that establishes a Talbot interference pattern, which may be a phase-shifting grating, and an x-ray detector to convert two-dimensional x-ray intensities into electronic signals. The system may comprise a second analyzer grating G2 that may be placed in front of the detector to form additional interference fringes, and a means to translate the second grating G2 relative to the detector. In some embodiments, the structures are microstructures with lateral dimensions measured in microns, and with a thickness on the order of one half of the electron penetration depth within the substrate. In some embodiments, the structures are formed within a regular array.

X-ray interferometric imaging system

This disclosure presents systems for total reflection x-ray fluorescence measurements that have x-ray flux and x-ray flux density several orders of magnitude greater than existing x-ray technologies. These may therefore useful for applications such as trace element detection and/or for total-reflection fluorescence analysis. The higher brightness is achieved in part by using designs for x-ray targets that comprise a number of microstructures of one or more selected x-ray generating materials fabricated in close thermal contact with a substrate having high thermal conductivity. This allows for bombardment of the targets with higher electron density or higher energy electrons, which leads to greater x-ray brightness and therefore greater x-ray flux. The high brightness/high flux source may then be coupled to an x-ray reflecting optical system, which can focus the high flux x-rays to a spots that can be as small as one micron, leading to high flux density.

X-ray surface analysis and measurement apparatus

This application discloses a compact source for high brightness x-ray generation. Higher brightness is achieved through electron beam bombardment of multiple regions aligned with each other to achieve a linear accumulation of x-rays. This is achieved by aligning discrete x-ray emitters, or through use of novel x-ray targets comprising a number of microstructures of x-ray generating materials fabricated in close thermal contact with a substrate with high thermal conductivity. This allows heat to be more efficiently drawn out of the x-ray generating material, and allows bombardment of this material with higher electron density and/or higher energy electrons, leading to greater x-ray brightness. The orientation of the microstructures allows the use of an on-axis collection angle, allowing accumulation of x-rays from several microstructures to be aligned, appearing to have a single origin, also known as "zero-angle" x-ray emission.

X-ray sources using linear accumulation

This disclosure presents systems for x-ray illumination that have an x-ray brightness several orders of magnitude greater than existing x-ray technologies. These may therefore useful for applications such as trace element detection or for micro-focus fluorescence analysis. The higher brightness is achieved in part by using designs for x-ray targets that comprise a number of microstructures of one or more selected x-ray generating materials fabricated in close thermal contact with a substrate having high thermal conductivity. This allows for bombardment of the targets with higher electron density or higher energy electrons, which leads to greater x-ray flux. The high brightness/high flux x-ray source may then be coupled to an x-ray optical system, which can collect and focus the high flux x-rays to spots that can be as small as one micron, leading to high flux density.

X-ray illuminators with high flux and high flux density

This disclosure presents systems for x-ray absorption fine structure (XAFS) measurements that have x-ray flux and flux density several orders of magnitude greater than existing compact systems. These are useful for laboratory or field applications of x-ray absorption near-edge spectroscopy (XANES) or extended x-ray fine absorption structure (EXFAS) spectroscopy. The higher brightness is achieved by using designs for x-ray targets that comprise a number of aligned microstructures of x-ray generating materials fabricated in close thermal contact with a substrate having high thermal conductivity. This allows for bombardment with higher electron density and/or higher energy electrons, leading to greater x-ray brightness and high flux. The high brightness x-ray source is then coupled to an x-ray reflecting optical system to collimate the x-rays, and a monochromator, which selects the exposure energy. Absorption spectra of samples using the high flux monochromatic x-rays can be made using standard detection techniques.

High brightness X-ray absorption spectroscopy system

The intensity of x-ray sources has increased at a rapid rate since the late 1960s by ten orders of magnitude and more through the use of synchrotron radiation produced by bending magnets, wigglers and undulators. Three generations of radiation sources have been identified depending on amplitude and quality of the radiation provided. While user facilities of the third generation were being constructed, a new concept of radiation generating devices was being developed that offers an even larger increase in peak and average brightness than had been achieved till then. The new concept of the x-ray free electron laser based on the principle of self-amplified spontaneous emission will be the basis of fourth generation x-ray source user facilities of this century. The paper will start with a brief history of the development of x-ray sources, it will then discuss some of the differences between storage ring and free electron laser based approaches, and will close with an update of the present development of x-ray free electron laser user facilities.

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Heinz-Dieter Nuhn

Papers

From Storage Rings to Free Electron Lasers for Hard X-Rays