Diaboloidal mirrors: algebraic solution and surface shape approximations.

A new type of optical element that can focus a cylindrical wave to a point focus (or vice versa) is analytically described. Such waves are, for example, produced in a beamline where light is collimated in one direction and then doubly focused by a single optic. A classical example in X-ray optics is the collimated two-crystal monochromator, with toroidal mirror refocusing.

Ex situ metrology and data analysis for optimization of beamline performance of aspherical pre-shaped x-ray mirrors at the advanced light source.

Super high quality aspherical x-ray mirrors with a residual slope error of ∼100 nrad (root-mean-square) and a height error of ∼1-2 nm (peak-to-valley), and even lower, are now available from a number of the most advanced vendors utilizing deterministic polishing techniques. The mirror specification for the fabrication is based on the simulations of the desired performance of the mirror in the beamline optical system and is normally given with the acceptable level of deviation of the mirror figure and finish from the desired ideal shape. For example, in the case of aspherical x-ray mirrors designed for the Advanced Light Source (ALS) QERLIN beamline, the ideal shape is defined with the beamline application (conjugate) parameters and their tolerances.

High precision tilt stage as a key element to a universal test mirror for characterization and calibration of slope measuring instruments.

The ultimate performance of surface slope metrology instrumentation, such as long trace profilers and auto-collimator based deflectometers, is limited by systematic errors that are increased when the entire angular range is used for metrology of significantly curved optics. At the ALS X-Ray Optics Laboratory, in collaboration with the HZB/BESSY-II and PTB (Germany) metrology teams, we are working on a calibration method for deflectometers, based on a concept of a universal test mirror (UTM) [V. V.

Development and calibration of mirrors and gratings for the soft x-ray materials science beamline at the Linac Coherent Light Source free-electron laser.

This work discusses the development and calibration of the x-ray reflective and diffractive elements for the Soft X-ray Materials Science (SXR) beamline of the Linac Coherent Light Source (LCLS) free-electron laser (FEL), designed for operation in the 500 to 2000 eV region. The surface topography of three Si mirror substrates and two Si diffraction grating substrates was examined by atomic force microscopy (AFM) and optical profilometry. The figure of the mirror substrates was also verified via surface slope measurements with a long trace profiler.

Mid-infrared reflectivity of experimental atheromas.

We report that the pathologic components present within the atheromatous plaques of ApoE knock-out mice can reflect significant amounts of mid-infrared (mid-IR) light. Furthermore, the reflected light spectra contained the unique signatures of a variety of biologic features including those found in unstable or "vulnerable" plaque. This discovery may represent a unique opportunity to develop a new intravascular diagnostic modality that can detect and characterize sites of atherosclerosis.

Surface roughness of stainless-steel mirrors for focusing soft x rays.

We have used polished stainless steel as a mirror substrate to provide focusing of soft x rays in grazing-incidence reflection. The critical issue of the quality of the steel surface, polished and coated with gold, is discussed in detail. A comparison is made to a polished, gold-coated, electroless nickel surface, which provides a smoother finish.

Suite of three protein crystallography beamlines with single superconducting bend magnet as the source.

At the Advanced Light Source, three protein crystallography beamlines have been built that use as a source one of the three 6 T single-pole superconducting bending magnets (superbends) that were recently installed in the ring. The use of such single-pole superconducting bend magnets enables the development of a hard X-ray program on a relatively low-energy 1.9 GeV ring without taking up insertion-device straight sections.

Very high power THz radiation at Jefferson Lab.

We report the production of high power (20 W average, approximately 1 MW peak) broadband THz light based on coherent emission from relativistic electrons. We describe the source, presenting theoretical calculations and their experimental verification. For clarity we compare this source with that based on ultrafast laser techniques, and in fact the radiation has qualities closely analogous to those produced by such sources, namely that it is spatially coherent, and comprises short duration pulses with transform-limited spectral content.

High-power terahertz radiation from relativistic electrons.

Terahertz (THz) radiation, which lies in the far-infrared region, is at the interface of electronics and photonics. Narrow-band THz radiation can be produced by free-electron lasers and fast diodes. Broadband THz radiation can be produced by thermal sources and, more recently, by table-top laser-driven sources and by short electron bunches in accelerators, but so far only with low power.

Synchrotron infrared spectromicroscopy as a novel bioanalytical microprobe for individual living cells: cytotoxicity considerations.

Synchrotron radiation-based Fourier transform infrared spectromicroscopy is a newly emerging analytical tool capable of monitoring the biochemistry within an individual living mammalian cell in real time. This unique technique provides infrared (IR) spectra, hence chemical information, with high signal to noise at spatial resolutions as fine as 3-10 microm. Mid-IR photons are too low in energy (0.

Catalysis of PAH biodegradation by humic acid shown in synchrotron infrared studies.

The role of humic acid (HA) in the biodegradation of toxic polycyclic aromatic hydrocarbons (PAHs) has been the subject of controversy, particularly in unsaturated environments. By utilizing an infrared spectromicroscope and a very bright, nondestructive synchrotron photon source, we monitored in situ and, over time, the influence of HA on the progression of degradation of pyrene (a model PAH) by a bacterial colony on a magnetite surface. Our results indicate that HA dramatically shortens the onset time for PAH biodegradation from 168 to 2 h.