Multilayer Laue lens (MLL) is a new class of x-ray optics that offer great promise for achieving nanometre-level spatial resolution by focusing hard x-rays. Fabricating an MLL via thin-film deposition provides the means to achieve a linear Fresnel-zone plate structure with zone widths below 1?nm, while retaining a virtually limitless aspect ratio. Despite its similarity to the Fresnel-zone plate, MLL exhibits categorically distinctive focusing properties and their fabrication comes with a wide array of challenges. This article provides a comprehensive review of advances in MLLs, and includes extensive theoretical modelling on focusing performance, discussion on fabrication challenges, their current capabilities and notable results from x-ray focusing experiments.

https://iopscience.iop.org/article/10.1088/0022-3727/47/26/263001/pdf

Hard x-ray nanofocusing by multilayer Laue lenses

Hard x-ray microscopy with nanometer resolution will open frontiers in the study of materials and devices, environmental sciences, and life sciences by utilizing the unique characterization capabilities of x-rays. Here we report two-dimensional nanofocusing by multilayer Laue lenses (MLLs), a type of diffractive optics that is in principle capable of focusing x-rays to 1 nm. We demonstrate focusing to a 25 × 27 nm2 FWHM spot with an efficiency of 2% at a photon energy of 12 keV, and to a 25 × 40 nm2 FWHM spot with an efficiency of 17% at a photon energy of 19.5 keV.

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Two dimensional hard x-ray nanofocusing with crossed multilayer Laue lenses

X-rays are intrinsically capable of being used for the study of non-periodic objects with atomic resolution, with high penetration, in applied electromagnetic fields, and in fluids and gases. For direct imaging via nanofocused X-ray beams, reflective [1], refractive [2], and diffractive [3, 4] optics are used in various approaches for high-resolution imaging. Diffractive X-ray optics are endowed with the highest numerical aperture, in principle allowing focusing of X-rays to sub-nanometer dimensions. Lithographically produced Fresnel zone plates (FZP) find broad deployment around the globe, in both nanofocusing and full-field imaging approaches, and have, for many years, been workhorse optics in both synchrotron-based and laboratory-based X-ray imaging systems [4]. A FZP consists of a series of radially symmetric rings, which are known as Fresnel zones, which alternate between transparent and opaque. Radiation traversing into the FZP diffracts around the opaque zones, which are placed in an arrangement wh...

Multilayer Laue Lens: A Brief History and Current Status

A multifunctional hard x-ray nanoprobe instrument for characterization of nanoscale materials and devices includes a scanning probe mode with a full field transmission mode. The scanning probe mode provides fluorescence spectroscopy and diffraction contrast imaging. The full field transmission mode allows two-dimensional (2-D) imaging and tomography. The nanoprobe instrument includes zone plate optics for focusing and imaging. The nanoprobe instrument includes a stage group for positioning the zone plate optics. The nanoprobe instrument includes a specimen stage group for positioning the specimen. An enhanced laser Doppler displacement meter (LDDM) system provides two-dimensional differential displacement measurement in a range of nanometer resolution between the zone-plate optics and the sample holder. A digital signal processor (DSP) implements a real-time closed-loop feedback technique for providing differential vibration control between the zone-plate optics and the sample holder.

Optomechanical structure for a multifunctional hard x-ray nanoprobe instrument

The invention relates to a cryogenic storage device and to a method for operating a cryogenic storage device, particularly for cryogenic storage of biological samples, comprising a sample carrying device that is set up to accommodate samples, a cryogenic container that is set up to accommodate the sample carrying device, a container cooling device with which the cryogenic container can be cooled, an intermediate storage container that is set up for intermediate storage of the sample carrying device, a transport device with which the sample carrying device can be moved between the cryogenic container and the intermediate storage container and a sensor device with which at least one operating parameter of the cryogenic storage device can be registered. The transport device is set up to be activated in dependence on an output signal from the sensor device upon registering a predetermined operating condition of the cryogenic storage device, so that the sample carrying device is moved from the cryogenic container to the intermediate storage container. Additionally or alternatively, an intermediate storage cooling device that is set up for cooling the intermediate storage container can be activated in dependence on an output signal of the sensor device.

Cryogenic storage device

A method and robot-based automation system are provided for cryogenic crystal sample mounting, for example, for use for cryogenic crystal sample mounting in the x-ray crystallography station at an x-ray source The system includes a robot arm carrying a handset The handset includes a pair of elongated fingers for sample mounting, and each finger carrying a set of strain gauge arrays for providing force sensing A slim finger design allows a sample mounting process with no interference with the beam stop, cryostreem and x-ray detectors The handset can detect the contact force intensity and direction; provide a precise gripping action; and feel the results of the gripping The finger design incorporates a mechanism to maintain the sample temperature well below the cryogenic safety margin for the crystal viability A Dewar container is provided with an ice control system and liquid nitrogen flow control A triangular sample magazine maximizes the Dewar space usage A miniature kinematical mounting sample holder provides near micron positioning repeatability These capabilities make the robot-arm more powerful, flexible, and reliable

Robot-based automation system for cryogenic crystal sample mounting

A multidimensional alignment apparatus is provided for multidimensional aligning of two linear multilayer Laue lenses (MLLs) for two-dimensional hard X-ray focusing. The multidimensional alignment apparatus precisely aligns and ensures stability of two linear MLLs performing hard x-ray focusing. The multidimensional alignment apparatus includes a base, a lower stages group controlling a first upstream MLL, an upper stages group positioned over the lower stages group controlling a second downstream MLL and an upper stage support attached to the base. The lower stages group provides five degrees of freedom precision positioning adjustment for the first upstream MLL. The second downstream MLL is mounted on the upper stages group with three degrees of freedom adjustment capability.

Multidimensional alignment apparatus for hard x-ray focusing with two multilayer laue lenses

Enhanced mechanical designs are provided for weak-link rotary mechanisms for implementing angular rotations with a defined angular travel range and positioning resolution, for example, with ten-degree-level travel range and ten-nanoradian-level positioning resolution. A weak-link rotary structure has a predetermined pattern for implementing angular rotations with repeatable and reliable angular travel range and positioning resolution including a plurality of connecting links radially extending from a central portion with a predefined angular separation between the connecting links; each said connecting link having at least one pair of weak-link connections; alternate connecting links being coupled to a respective terminal, each said respective terminal being mounted to a connecting carriage; remaining other connecting links being coupled to a respective mounting portion of a mating part of the weak-link rotary structure.

Mechanical design of laminar weak-link rotary mechanisms with ten-degree-level travel range and ten-nanoradian-level positioning resolution

A stage or support platform assembly for use in a synchrotron accurately positions equipment to be used in the beam line of the synchrotron. The support platform assembly includes an outer housing in which is disposed a lifting mechanism having a lifting platform or stage at its upper extremity on which the equipment is mounted. A worm gear assembly is located in the housing and is adapted to raise and lower a lifting shaft that is fixed to the lifting platform by an anti-binding connection. The lifting platform is moved vertically as the lifting shaft is moved vertically. The anti-binding connection prevents the shaft from rotating with respect to the platform, but does permit slight canting of the shaft with respect to the lifting platform so as to eliminate binding and wear due to possible tolerance mismatches. In order to ensure that the lifting mechanism does not move in a horizontal direction as it is moved vertically, at least three linear roller bearing assemblies are arranged around the outer-periphery of the lifting mechanism. One of the linear roller bearing assemblies can be adjusted so that the roller bearings apply a loading force against the lifting mechanism. Alternatively, a cam mechanism can be used to provide such a loading force.

Deming Shu

Papers

Optomechanical structure for a multifunctional hard x-ray nanoprobe instrument

Robot-based automation system for cryogenic crystal sample mounting

Multidimensional alignment apparatus for hard x-ray focusing with two multilayer laue lenses

Mechanical design of laminar weak-link rotary mechanisms with ten-degree-level travel range and ten-nanoradian-level positioning resolution

Low profile, high load vertical rolling positioning stage