Crystal-based x-ray optics are widely used in the synchrotron radiation field. Such optics include monochromators,
channel-cut crystals, spectral analyzers, and phase plates that are generally made with standard fabrication tools such as
grinders, ultrasonic mills, blade saws, and wire saws. However, modern synchrotron radiation instruments require more
complicated and high-precision crystal structures that cannot be fabricated by these conventional tools. Examples include
narrow channels and crystal cavities that require smooth and strain-free sidewalls or inner surfaces. Since it is extremely
difficult to polish such surfaces by conventional means, specialized cutting tools are required to make the as-cut surfaces
as smooth as possible. A possible way to obtain such smooth surfaces is to use a dicing saw as a fabrication tool - a tool
typically used in the microelectronics industry to cut or dice semiconductor and other materials. Here we present our
studies on the use of dicing saws for cutting innovative, monolithic, x-ray optic devices comprised of tall, narrow-standing,
thin crystal-plate arrays. We report cutting parameters that include the rotational speed of the cutting blade
(a.k.a. spindle speed), cutting speed (a.k.a. feed rate), number of passes for each cut depth (if required), and diamond grit
size for producing the flattest and most smooth side walls. Blade type and construction (sintered, Ni, and resin) also play
critical roles in achieving optimum results. The best experimental data obtained produced an average surface roughness
of 49 nm and a peak-to-valley flatness of 3625 nm. By achieving these results, we have been able to assist experimenters
in the synchrotron radiation field in their efforts to create functional and novel optical devices.
The use of high quality X-ray mirrors at synchrotron beamlines as low-energy bandpass, harmonic rejection and high
heat load optical elements has become routine. Nearly perfect optical surfaces generated on substrates and held in strain-free
fixtures are of paramount importance to their success. Production of these mirrors requires extensive care, yet the
effect of residual fabrication stress has not been closely studied. This paper examines the effect of surface and near-surface
residual stress on the performance of hard X-ray mirrors using topography and X-ray reflectivity techniques. The
present approach complements the information provided by standard optical metrology, giving a more comprehensive
understanding of polishing induced surface deformation on X-ray reflectivity. This information is invaluable for the
characterization of future, coherence preserving optics where scattering and evanescent sub-surface X-ray penetration
may impact beam quality.
Kirkpatrick-Baez (KB) mirrors consist of two individual mirrors: one vertical focusing mirror and one horizontal
mirror at separate positions. Nested (Montel) KB mirrors consist of two mirrors arranged perpendicularly to each
other and side-by-side. We report our results from the fabrication and tests of the first set of nested KB mirrors for a
synchrotron hard x-ray micro/nano-focusing system. The elliptically shaped nested Platinum KB mirrors include
two 40 mm long mirrors fabricated by depositing Platinum on Silicon substrates using the magnetron sputtering
technique. Hard x-ray synchrotron tests have been performed at 15 keV and 2D focal spots of approximately 150 nm
x 150 nm (FWHM) were achieved from both monochromatic and polychromatic beams at the 34 ID beamline of the
Advanced Photon Source (APS) at Argonne National Laboratory. The side-by-side arrangement of nested KB
mirrors requires them to have good surfaces and low figure errors at the intersection of the two mirrors' surfaces. It
is very challenging to fabricate substrates that fit the nested KB mirror's arrangement and to deposit thin films to
ideal elliptical shapes at the edge of the mirrors. Further research and development will be performed in the areas of
fabrication and testing with respect to nested KB mirrors used in micro/nano-focusing systems. In particular,
substrate processing and deposition techniques should be examined to improve the performance of the mirrors.
A prototype of a novel ultrahigh-resolution inelastic x-ray scattering spectrometer has been designed and tested at
undulator-based beamline 30-ID, at the Advanced Photon Source (APS), Argonne National Laboratory. This state-of-the-art instrument is designed to meet challenging mechanical and optical specifications for producing ultrahigh-resolution inelastic x-ray scattering spectroscopy data for various scientific applications.
The optomechanical design of the ultrahigh-resolution monochromator and analyzer for inelastic x-ray scattering spectrometer as well as the preliminary test results of its precision positioning performance are presented in this paper.
Beryllium windows are used on many X-ray synchrotron beamlines to separate and protect the ultra-high vacuum of the
storage ring from the experimental environment. Currently, such a window is typically made of a thin, high-purity,
beryllium foil, which may or may not have been polished. It is well known that these windows affect the transmitted
beam quality. The impact ranges from non-perceptible to profound, depending on the experiment.
The degradation of the X-ray beam is of increasing importance and concern, however, and in fact a number of beamlines
now are run windowless or with a very small and thin silicon nitride window. There remain many instances where a
large and robust window is desirable or necessary, and it is for this reason that developing windows that have little or no
impact on the transmitted X-ray beam quality is important.
This presentation reports on the progress in developing single-crystal beryllium X-ray windows. Due to its high purity
and homogeneity, relative structural perfection, and high polishiblity single-crystal beryllium is an attractive window
material candidate, particularly for beamlines conducting imaging or coherence-based experiments. Development of
thin and uniform windows with less than 1 nm rms surface roughness and their preliminary characterization results are
presented.
Channel-cut monochromators can be easily incorporated in high-resolution image techniques. However, polishing on the inner diffracting surfaces is difficult because of blockage by the opposite face. To address this difficulty, an open-faced monolithic monochromator has been designed, produced and tested using x-rays at the Advanced Photon Source (APS). The open-faced channel cut has a “Z”-shape geometry with a hole in the mid section to allow passage of the diffracted beam. The open geometry allowed chemical mechanical polishing so that an optically smooth finish on both surfaces was achieved. The high-resolution x-ray imaging and topography measurements revealed that the new design introduces significantly less distortions in the phase-contrast images compared with conventional channel-cut monochromators produced using etching alone.
This paper describes the design and analysis of a contact-cooled channel-cut germanium monochromator for use on a high-heat-load x-ray beamline. This channel-cut monochromator is designed in the shape of a "Z" so that polishing the diffraction surfaces is easier. The incident x-ray beam, which is reflected from a mirror at a 0.15° angle, diffracts from one surface of the Z-monochromator, passes through an opening, and diffracts from the second surface. The monochromator is located 60 meters from the undulator x-ray source. The normal heat flux of the incident beam can be up to 7 W/mm2. Thermal and structural analyses are presented, and the deformation caused by gravity is considered.
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