Other

Bruker Axs Gmbh

Christoph Ollinger

Roger David Durst

Juergen Graf

Bob Baoping He

Carsten Michaelsen

Joerg Kaercher

Norbert Kuhnmuench

Christian Maurer

Andreas Kleine

Olaf Meding

Sergey Lazarev

Norbert Kuhnmünch

Jürgen Graf

Roger D Durst

Roger Durst

Bob Boaping He

A method for correcting distortion in a coherent electron diffraction imaging (CEDI) image induced by a projection lens makes use of a known secondary material that is imaged together with a sample of interest. Reflections generated from the secondary material are located in the image, and these observed reflections are used to approximate a beam center location. Using a known lattice structure of the secondary material, Friedel pairs are located in the image and unit cell vectors are identified. Predicted positions for each of the secondary material reflections are then determined, and the position differences between the observed reflections and the predicted reflections are used to construct a relocation function applicable to the overall image. The relocation function is then used to adjust the position of image components so as to correct for the distortion.

Method for the detection and correction of lens distortions in an electron diffraction system

An X-ray laser has a target anode of a crystalline material that emits X-ray radiation in response to excitation and that is located on a thermally conductive substrate. An X-ray source provides an input X-ray beam that illuminates a predetermined volume of the target anode at a predefined angle relative to a surface of the anode so as to induce a Borrmann mode standing wave in the predetermined volume. An electron source outputs an electron beam that is incident on the Borrmann mode region so as to cause electron impact ionization of the crystalline material and thereby induce stimulated emission of a coherent output X-ray beam.

Stimulated X-ray emission source with crystalline resonance cavity

An electron diffraction imaging system for imaging the three-dimensional structure of a single target molecule of a sample uses an electron source that emits a beam of electrons toward the sample, and a two-dimensional detector that detects electrons diffracted by the sample and generates an output indicative of their spatial distribution. A sample support is transparent to electrons in a region in which the sample is located, and is rotatable and translatable in at least two perpendicular directions. The electron beam has an operating energy between 5 keV and 30 keV, and beam optics block highly divergent electrons to limit the beam diameter to no more than three times the size of the sample molecule and provide a lateral coherence length of at least 15 nm. An adjustment system adjusts the sample support position in response to the detector output to center the target molecule in the beam.

Electron diffraction imaging system for determining molecular structure and conformation

An X-ray source uses excitation of a liquid metal beam of ions or ionized droplets to produce an X-ray output with higher brightness than conventional sources. The beam may be accelerated from a liquid metal source using an extraction electrode. The source may have an emitter tip, and the acceleration of the liquid metal may include field emission from a Taylor cone. An electrostatic or electromagnetic focusing electrode may be used to reduce a cross-sectional diameter of the beam. The liquid metal beam has a relatively high velocity as it does not suffer from flow turbulence, thus allowing for a more energetic excitation and a correspondingly higher brightness. A beam dump may also be used to collect the liquid metal beam after excitation, and may be concave with no direct sight lines to either an electron beam cathode or to X-ray windows of an enclosure for the source.

X-ray source using electron impact excitation of high velocity liquid metal beam

An x-ray apparatus (), has an electron beam source (), a target (), onto which the electron beam () is directed to form a focal spot () on the target (), x-ray optics () for collecting x-rays emitted from the focal spot () to form an x-ray beam () and a sample position () at which the x-ray beam () is directed. The x-ray apparatus () further includes an electrostatic or electromagnetic electron beam deflection device () suitable for moving the focal spot () on the target (). The extension of the focal spot () in any direction (x, y, z) is at least a factor of 1.5 smaller than the extension of the target (). An x-ray apparatus is thereby provided with simplified alignment of the x-ray optics with respect to a microfocus x-ray source.

X-ray apparatus with deflectable electron beam

An X-ray diffraction system uses a two-dimensional detector to detect diffracted X-ray energy at a plurality of radial positions surrounding a sample location, the results at each position being combined to form a final diffraction image. To minimize smearing in the final image, the detector pixel intensities at each position are reapportioned among the pixel locations prior to being combined with the intensities collected at other positions. A two-dimensional pixel array space of the detector is projected onto a cylinder to form a projected pixel array space, and a virtual cylindrical detection surface representative of an ideal cylindrical detector is determined. An overlap between the pixels of the projected pixel array space and the pixels of the virtual cylindrical detection surface is determined, and pixel intensities are reapportioned accordingly. The reapportionment may include dividing each pixel space into subpixels and redistributing the subpixels among adjacent pixels.

Method for collecting accurate X-ray diffraction data with a scanning two-dimensional detector

An X-ray optical configuration (), comprising a position for an X-ray source (), a position for a sample (), a first focusing element () for directing X-ray radiation from the position of the X-ray source () via an intermediate focus () onto the position of the sample (), and an X-ray detector () that can be moved on a circular arc () of radius R around the position of the sample (), is characterized in that the configuration also comprises a second focusing element () for directing part of the X-ray radiation emanating from the intermediate focus () onto the position of the sample (), and an aperture system () for selecting between illumination of the position of the sample () exclusively and directly from the intermediate focus () (=first optical path (')), or exclusively via the second focusing element () (=second optical path (&#x2033;)). The configuration facilitates changing between reflection geometry and transmission geometry, in particular, wherein modification and adjustment devices are minimized or unnecessary.

X-ray optical configuration with two focusing elements

An X-ray optical element () with a Soller slit comprising several lamellas for collimating an X-ray beam with respect to the direction of the axis () of the Soller slit, and a further collimator for delimiting an X-ray (), wherein the further collimator is rigidly connected to the Soller slit () during operation, is characterized in that the X-ray beam () delimited by the further collimator intersects the axis () of the Soller slit within the Soller slit, and the direction of the X-ray beam () subtends an angle &#x3b1;&#x2267;10&#xb0; with respect to the axis () of the Soller slit. An X-ray optical element () with a Soller slit () and a further collimator is thereby realized, which permits automatic change between the Soller slit () and the further collimator.

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Karlsruhe, Germany

Christoph Ollinger