Active microstructured arrays for x-ray optics
Author(s):
Alan Michette;
Tim Button;
Camelia Dunare;
Charlotte Feldman;
Melvyn Folkard;
David Hart;
Chris McFaul;
Graeme R. Morrison;
William Parkes;
Sławka Pfauntsch;
A. Keith Powell;
Daniel Rodriguez-Sanmartin;
Shahin Sahraei;
Tom Stevenson;
Boris Vojnovic;
Richard Willingale;
Dou Zhang
Show Abstract
The UK Smart X-Ray Optics programme is developing the techniques required to both enhance the performance of
existing X-ray systems, such as X-ray telescopes, while also extending the utility of X-ray optics to a broader class of
scientific investigation. The approach requires the control of the inherent aberrations of X-ray systems using an
active/adaptive method. One of the technologies proposed to achieve this is micro-structured optical arrays, which use
grazing incidence reflection through consecutive aligned arrays of channels. Although such arrays are similar in concept
to polycapillary and microchannel plate optics, they are more flexible. Bending the arrays allows variable focal length,
while flexing parts of them provides adaptive or active systems. Custom configurations can be designed, using ray
tracing and finite element analysis, for applications from sub-keV to several-keV X-rays. The channels may be made
using deep silicon etching, which can provide appropriate aspect ratios, and flexed using piezo actuators. An exemplar
application will be in the micro-probing of biological cells and tissue samples using Ti Kα radiation (4.5 keV) in studies
related to radiation induced cancers.
The new ESRF multilayer deposition facility
Author(s):
Ch. Morawe;
Ch. Borel;
J.-Ch. Peffen
Show Abstract
Recently, the ESRF Optics Group installed a new multilayer deposition facility. This upgrade was motivated by
increasingly demanding requirements for multilayer based x-ray optics on modern 3rd generation synchrotron
beamlines. Improved accuracy, stability, and reproducibility are key issues.
The deposition process is based on non-reactive magnetron sputtering. The machine is equipped with four cathodes
and one ion source for surface treatment. Conducting, insulating, and ferromagnetic materials can be deposited. A
linear substrate motion will enable coatings up to 100 cm long and 15 cm wide.
The talk will describe the basic concept of the machine and will give an overview of the operating conditions. Initial
coating results will complement the presentation.
Multilayer growth in the APS rotary deposition system
Author(s):
Ray Conley;
Chian Liu;
Cameron M. Kewish;
Albert T. Macrander;
Christian Morawe
Show Abstract
We report our progress in the growth of periodic and depth-graded multilayers in the APS rotary deposition system, a
machine designed for fabrication of films tens of microns thick with thousands of layers. A computational method was
employed to design depth-graded multilayers for use as wide-angular bandpass reflective optics. We present
experimental results for a 154-layer WSi2/Si multilayer system with bilayer thickness ranging from 2.2 nm to 5.5 nm that
closely match theoretical flat-top reflectivity predictions of 9.8% from 15.6 mrad to 23.3 mrad at 8 keV.
Silicon planar lenses for high-energy x-ray nanofocusing
Author(s):
A. A. Snigirev;
I. Snigireva;
M. Grigoriev;
V. Yunkin;
M. Di Michiel;
S. Kuznetsov;
G. Vaughan
Show Abstract
Optimizing the lens design and improving the technological process, we manufactured X-ray planar compound refractive
lenses with vertical sidewalls up to 70 microns deep. The lens surface roughness in the order of 20 nm was attained. The
minimal thickness of the material between two individual lenses of 2 µm was realized. Driven by the requirements of
new 100 m-long beamlines at the ESRF, the first prototype chip of Si planar nanofocusing lenses was designed and
manufactured. The technological breakthrough allows to reach the nanometer focusing. The optical tests of the new
planar lenses were performed at the ESRF beamlines BM5 and ID15. The resolution below 200 nm was measured in the
energy region of 15-80 keV. The best resolution of 150 nm was demonstrated at 50 keV energy. As a next step dedicated
chip design for two-dimensional focusing with nanopositioning stages will be realized.
Development of refractive x-ray focusing optics at Diamond Light Source
Author(s):
L. Alianelli;
K. J. S. Sawhney;
I. M. Loader;
D. W. K. Jenkins;
R. Stevens;
A. Snigirev;
I. Snigireva
Show Abstract
The Diamond Optics & Metrology Group and the collaborators at the STFC Central Microstructure Facility have
initiated a program for the design and fabrication of in-line micro- and nano-focusing optics for synchrotron radiation
beamlines. The first type of optics fabricated is a kinoform lens in silicon on the same model proposed by K. Evans-
Lutterodt et al [Opt. Expr. 11 (2003) 919.]. The fabrication utilised ultra high resolution electron beam lithographic
patterning of an electron sensitive SU8 polymer and deep reactive ion etching of silicon. The first test of the focusing
properties was performed at the ESRF BM5 optics beamline. In this paper we present details on the design and
fabrication, and discuss the test results.
Nanopositioning of the silicon planar lenses used for 2D high energy x-ray nanofocusing
Author(s):
P. Van Vaerenbergh;
A. Snigirev;
M. A. Nicola;
I. Snigireva;
M. Grigoriev;
V. Yunkin;
G. Vaughan;
L. Claustre;
H-P. Van Der Kleij;
J-Y. Massonnat
Show Abstract
Nanopositioners have been integrated into a system to perform 2D focusing of the X-ray beam by using silicon planar
lenses in cross geometry. Those positioners have been tested in the ESRF metrology laboratory to measure their
resolutions. The whole system was found to have a good tunability; it is compact and led to an easy alignment of the two
lenses along the common beam axis. Experiments were made with this system at the BM05 ESRF beamline using the
Micro-optics test bench.
Projection-type x-ray microscope based on a spherical compound refractive x-ray lens
Author(s):
Yu. I. Dudchik;
C. K. Gary;
H. Park;
R. H. Pantell;
M. A. Piestrup
Show Abstract
New projection- type X-ray microscope with a compound refractive lens as the optical element is presented. The microscope consists of an X-ray source that is 1-2 mm in diameter, compound X-ray lens and X-ray camera that are placed in-line to satisfy the lens formula. The lens forms an image of the X-ray source at camera sensitive plate. An object is placed between the X-ray source and the lens as close as possible to the source, and the camera shows a shadow image of the object. Spatial resolution of the microscope depends on the lens focal length, lens aperture and the distance from the source to the object. One to two micron resolution may be achieved by placing the object at a distance of 1-5mm from the source. The X-ray source may be designed with the target deposited on a 200-μm thick Be window, which permits the object to be placed very close to the emitting surface. The tube focal spot is equal to 1-2 mm. Results of imaging experiments with an ordinary copper anode X-ray tube and a 10-cm focal length spherical compound refractive X-ray lens are discussed.
Deposition and analysis of small d-spacing depth graded multilayer structures
Author(s):
David M. Broadway;
Yuriy Y. Platonov;
Roberto Mancini;
Riccardo Tommasini
Show Abstract
A method for the determination of the deposited layer thickness distribution through the stack has been presented in a
previous article [1]. We illustrate the validity of this model by considering the deposition of a Mo/B4C design. This
method is further improved to allow for the additional determination of roughness/diffusion through the multilayer stack.
We show results of the analysis for a deposited small d-spacing W/B4C design (davg=1.5nm) which give compelling
evidence for the existence and determination of a minimum value of thickness that can be allowed in the design of the
structure. From this analysis the multilayer was redesigned with a constraint on the minimum thickness allowed in the
stack. We show successful results of the deposited redesigned structure. Finally, we show the influence of random
layer thickness error on the resultant reflectivity.
XUV optics for attosecond applications
Author(s):
J. Gautier;
A. S. Morlens;
P. Zeitoun;
G. Rey;
C. Valentin;
E. Papalarazou;
J. P. Goddet;
S. Sebban;
F. Delmotte;
M. F. Ravet;
F. Bridou
Show Abstract
Among X-ray and extreme ultraviolet light sources able to produce shorter and shorter, coherent and intense pulses, High
order harmonics generated in rare gases are currently the unique way to generate attosecond pulses. However, the
manipulation and transport of attosecond pulses require the development of dedicated optics for reaching specific
characteristics in terms of amplitude but also in terms of spectral phase control. We present here a multilayer design for
chirp compensation of attosecond pulses. We also present an application of these multilayers mirrors for attosecond train
pulse holography experiment with high harmonics. This experience took benefit of both temporal and spatial phase
properties of high harmonics. A resolution of 750 nm has been achieved by using a 350 as train pulse for the reference
wave constituted of four consecutive harmonics (λ=28 nm to λ=41 nm). This new method will allow making ultra fast
movies with attosecond resolution of transient phenomena with quasi-3D resolution.
Metrology of micromirrors with replicated multilayers
Author(s):
L. Sveda;
A. Inneman;
V. Semencova;
L. Pina;
R. Hudec;
R. Havlikova
Show Abstract
Replicated multilayers inside the rotationally symmetric x-ray mirrors with diameter 0.5-4 mm are being investigated.
While the replicated Micromirror technology as well as replicated multilayers on the planar surface were
already studied, we present here the combination of both technologies. Initial simulations and development of
metrology of multilayers inside small cavities are described, as well as very first results of experiments.
Development of an ultrahigh-resolution diffraction grating for soft x-rays
Author(s):
Dmitriy L. Voronov;
Rossana Cambie;
Ruslan M. Feshchenko;
Eric M. Gullikson;
Howard A. Padmore;
Alexander V. Vinogradov;
Valeriy V. Yashchuk
Show Abstract
Resonant Inelastic X-ray Scattering (RIXS) is the one of the most powerful methods for investigation of the electronic
structure of materials, specifically of excitations in correlated electron systems. However the potential of the RIXS
technique has not been fully exploited because conventional grating spectrometers have not been capable of achieving
the extreme resolving powers that RIXS can utilize. State of the art spectrometers in the soft x-ray energy range achieve
~0.25 eV resolution, compared to the energy scales of soft excitations and superconducting gap openings down to a
few meV. Development of diffraction gratings with super high resolving power is necessary to solve this problem. In
this paper we study the possibilities of fabrication of gratings of resolving power of up to 106 for the 0.5 - 1.5 KeV
energy range. This energy range corresponds to all or most of the useful dipole transitions for elements of interest in
most correlated electronic systems, i.e. oxygen K-edge of relevance to all oxides, the transition metal L2,3 edges, and the
M4,5 edges of the rare earths. Various approaches based on different kinds of diffraction gratings such as deep-etched
multilayer gratings, and multilayer coated echelettes are discussed. We also present simulations of diffraction efficiency
for such gratings, and investigate the necessary fabrication tolerances.
Zone plate efficiency measurements with a laser-plasma source
Author(s):
Michael C. Bertilson;
Per A. C. Takman;
Anders Holmberg;
Ulrich Vogt;
Hans M. Hertz
Show Abstract
We demonstrate a compact instrument for rapid and accurate measurements of the absolute and local efficiency of soft x-ray
zone plates in the water window [M. Bertilson, et al, Rev. Sci. Instrum 78, 026103 (2007)]. The arrangement is based
on a new single-line λ = 2.88 nm liquid-nitrogen-jet laser-plasma source. The versatility of the instrument enables micro
and condenser zone plates with focal lengths in the range from ~200 μm to ~100 mm to be measured. We demonstrate an
accurate local efficiency map of a in-house fabricated micro zone plate. Furthermore, we show how this compact
instrument allows rapid feedback to the fabrication process which is important for future improvements.
Hard x-ray focusing by stacked Fresnel zone plates
Author(s):
Irina Snigireva;
Anatoly Snigirev;
Viktor Kohn;
Vyacheslav Yunkin;
Maxim Grigoriev;
Serguei Kuznetsov;
Gavin Vaughan;
Marco Di Michiel
Show Abstract
Stacking technique was developed in order to increase focusing efficiency of Fresnel zone plates at high energies. Two
identical Si chips each of which containing Fresnel zone plates were used for stacking. Alignment of the chips was
achieved by on-line observation of the moiré pattern from the two zone plates. The formation of moiré patterns was
studied theoretically and experimentally at different experimental conditions. To provide the desired stability Si-chips
with zone plates were bonded together with slow solidification speed epoxy glue. Technique of angular alignment in
order to compensate a linear displacement in the process of gluing was proposed. Two sets of stacked FZPs were
produced and experimentally tested to focus 15 and 50 keV X-rays. Gain in the efficiency by factor 2.5 was
demonstrated at 15 keV. Focal spot of 1.8 μm vertically and 14 μm horizontally with 35% efficiency was measured at
50 keV. Forecast for the stacking of nanofocusing Fresnel zone plates was discussed.
Characterization of beryllium and CVD diamond for synchrotron radiation beamline windows and x-ray beam monitor
Author(s):
S. Goto;
S. Takahashi;
T. Kudo;
M. Yabashi;
K. Tamasaku;
Y. Nishino;
T. Ishikawa
Show Abstract
We characterized beryllium foils and CVD diamond films/plates for synchrotron radiation beamline windows and x-ray
beam monitor especially in coherent x-ray applications. Sub-micron-resolution imaging with a zooming tube was
performed using spatially coherent x-rays at 1-km beamline 29XU of SPring-8. We found that the speckles observed in
the conventional powder and ingot beryllium foils were due to voids with diameter of several to ten-several microns. The
physical vapor deposition (PVD) eliminated the voids and the PVD beryllium showed the best performance with no
speckles. We characterized a commercially available polycrystalline CVD diamond window and CVD films as well as
beryllium foils. Polished thin diamond film showed rather uniform transmission image. We found dark spots at in-line
image due to Bragg diffraction from grains for thicker CVD diamond window.
Simulation of partially coherent image formation in x-ray microscopy
Author(s):
O. von Hofsten;
M. C. Bertilson;
U. Vogt
Show Abstract
We present the theory and implementation of a numerical model capable of simulating two-dimensional images for an x-ray
microscope using partially coherent illumination considerations. Partially coherent illumination is found in all x-ray
microscopes and particularly in the latest generation of our in-house compact soft x-ray microscope. This is due to an
introduced mismatch in numerical aperture of the condenser and objective zone plate, and will yield diffraction-like
artifacts in phase-shifting objects. The numerical model approximates the condenser zone plate as a secondary incoherent
source represented by individually coherent but mutually incoherent source emitters, each giving rise to a separate
image. A final image is obtained by adding up the image intensities of the individual contributions. The simulation has
been a useful tool for investigating the influence of coherence on images in both the mirror and zone plate condenser
arrangement of the in-house compact soft x-ray microscope. The latest development included in the program is the effect
of astigmatism and partial coherence, where the calculated results show good qualitative agreement with respect to the
microscope images.
Analysis and modification of x-ray mutual coherence with perfect-crystal diffraction
Author(s):
Hiroshi Yamazaki;
Tetsuya Ishikawa
Show Abstract
X-ray diffraction by perfect crystal is discussed from the viewpoint of mutual coherence of an x-ray beam. From
the time-dependent Takagi-Taupin equations that x-ray wavefields obey in crystal, the reflected wavefield is
formulated as an integral transform of a general incident wavefield with temporal and spatial inhomogeneity.
A reformulation of rocking-curve profile from the field solution of the time-dependent Takagi-Taupin equations
allows experimental evaluation of the mutual coherence function of an x-ray beam. The rigorous relationship of
the coherence functions before and after reflection clarifies how the coherence is transferred by a crystal.
Diamonds for x-ray optical applications at 3rd and 4th generation x-ray sources
Author(s):
R. C. Burns;
A. Chumakov;
G. Carbone;
S. H. Connell;
D. Dube;
H. P. Godfried;
J. O. Hansen;
J. Härtwig;
F. Masiello;
M. Rebak;
A. Rommeveaux;
R. Setshedi;
P. Van Vaerenbergh;
A. Gibaud
Show Abstract
There is currently interest in low strain HPHT diamond due to its expected application as various types of X-ray optical
elements at Synchrotrons, where the X-ray intensity is becoming progressively too severe for the existing materials. The
diamond crystals need to be synthesised with unprecedented lattice quality. In recent measurements at the ID19
beamline of European Synchrotron Radiation Facility (ESRF), the strain sensitivity of the (quantitative) X-ray plane
wave monochromatic topography was increased to the level of 10-8 using the double crystal technique with successively
higher order reflections and correspondingly higher energy X-rays. At this level the strain fields of certain defects have
a clearly visible macroscopic extent. In particular, both compressive and tensile strain fields of sparse single
dislocations are well observed, as are long range strain fields due to isolated surface scratches. The surface processing
of diamond for low roughness and good near surface crystal quality is a priority. A study of the progress towards this
goal using the X-ray techniques of reflectivity, Grazing Incidence small angle X-ray Scattering (GISAXS) and Grazing
Incidence X-ray Diffraction (GID) has been undertaken. The ability of diamond X-ray optical elements to process X-ray
beams while preserving the coherence properties of the beam is essential to establish, and measurements of this via the
Talbot effect have been carried out. This contribution will detail some of the latest results and comment on future
prospects.
Reflective optics for sub-10nm hard x-ray focusing
Author(s):
H. Mimura;
S. Matsuyama;
H. Yumoto;
S. Handa;
T. Kimura;
Y. Sano;
K. Tamasaku;
Y. Nishino;
M. Yabashi;
T. Ishikawa;
K. Yamauchi
Show Abstract
Nanofocused X-rays are indispensable because they can provide high spatial resolution and high sensitivity for X-ray
nanoscopy/spectroscopy. A focusing system with reflective optics is one of the most promising methods for producing
nanofocused X-rays due to its high efficiency and beams size. So, far we realize efficient hard X-ray focusing with a
beam size of 25nm. Our next project is realization of sub-10nm hard X-ray focusing. Here, we describe the design of
the graded multilayer mirror and evaluation method for hard X-ray focused beam.
Large thin adaptive x-ray mirrors
Author(s):
Peter Doel;
Carolyn Atkins;
Samantha J. Thompson;
David Brooks;
Jun Yao;
Charlotte Feldman;
Richard Willingale;
Tim Button;
Dou Zhang;
Ady James
Show Abstract
This paper describes the progress made in a proof of concept study and recent results of a research program into large
active x-ray mirrors that is part of the UK Smart X-ray Optics project. The ultimate aim is to apply the techniques of
active/adaptive optics to the next generation of nested shell astronomical X-ray space telescopes.
A variety of deformable mirror technologies are currently available, the most promising of which for active X-ray
mirrors are probably unimorph and bimorph piezoelectric mirrors. In this type of mirror one or more sheets of
piezoelectric material are bonded to or coated with a passive reflective layer. On the back or between the piezoceramic
layer/layers are series of electrodes. Application of an electric field causes the piezoelectric material to undergo local
deformation thus changing the mirror shape. Starting in 2005 a proof of concept active mirror research program has
been undertaken. This work included modelling and development of actively controlled thin shell mirrors. Finite
element models of piezo-electric actuated mirrors have been developed and verified against experimental test systems.
This has included the modelling and test of piezo-electric hexagonal unimorph segments. Various actuator types and low
shrinkage conductive bonding methods have been investigated and laboratory tests of the use of piezo-electric actuators
to adjust the form of an XMM-Newton space telescope engineering model mirror shell have been conducted and show
that movement of the optics at the required level is achievable. Promising technological approaches have been identified
including moulded piezo-ceramics and piezo-electrics fibre bundles.
Effect of x-ray beamline optics on x-ray photon correlation spectroscopy experiments
Author(s):
A. R. Sandy;
K. Evans-Lutterodt;
K. Fezzaa;
S. Kim;
S. Narayanan;
M. Sprung;
A. G. Stein
Show Abstract
We have evaluated the applicability of vertically-focusing kinoform lenses for tailoring the vertical coherence
length of storage-ring undulator x-ray beams so that the entirety of the coherent flux can be used for small
angle multi-speckle x-ray photon correlation spectroscopy (XPCS) experiments. We find that the focused beam
produced by a kinoform lens preserves the coherence of the incident unfocused beam and that at an appropriate
distance downstream of the focus, the diverging beam produces speckles nearly identical to those produced by
an equivalently-sized unfocused beam. We have also investigated the effect of imperfect beamline optics on the
observed coherence properties of the beam. Via phase contrast imaging and beam-divergence measurements,
we find that a horizontally-deflecting mirror in our beamline precludes us from seeing the true radiation source
point but instead acts as an apparent source of fixed size at the center of our insertion device straight section.
Finally, we discuss how expected near-future optimization of these optics will greatly benefit XPCS measurements
performed at beamline 8-ID-I at the Advanced Photon Source.
Soft x-ray mirrors for the Linac Coherent Light Source
Author(s):
M. J. Pivovaroff;
R. M. Bionta;
T. J. Mccarville;
R. Soufli;
P. M. Stefan
Show Abstract
The Linac Coherent Light Source (LCLS) is a 0.15-1.5 nm wavelength free-electron laser (FEL) being constructed
at the Stanford Linear Accelerator Center (SLAC) by a multi-institution consortium, including Lawrence Livermore
National Laboratory (LLNL). One of LLNL's responsibilities involves the design and construction of two
grazing-incidence mirror systems whose primary intent is to reduce radiation levels in the experimental halls by
separating the FEL beam from unwanted high-energy photons.
This paper discusses one of these systems, the Soft X-ray Offset Mirror System (SOMS) that will operate
in the wavelength range 0.62-1.5 nm (0.827-2.00 keV). The unusual properties of the FEL beam translate
to stringent specifications in terms of stability, material choice and mirror properties. It also precludes using
approaches previously developed for synchrotron light sources. This situation has led us to a unique mirror
design, consisting of a reflective boron carbide layer deposited on a silicon substrate. In the first part of this
paper, we discuss the basic system requirements for the SOMS and motivate the need for these novel reflective
elements. In the second part of this paper, we discuss the development work we have performed, including
simulation and experimental verification of the boron carbide coating properties, and the expected performance
of the final system.
Beam-splitting mirrors for an APS beamline
Author(s):
Ali M. Khounsary;
Ian McNulty
Show Abstract
We describe a set of two cooled mirrors used in tandem on a high-heat-load undulator beamline at the Advanced Photon
Source (APS) to spatially split an incoming X-ray beam into two parts, allowing simultaneous operation on two
beamlines. Such arrangements have the potential to increase beamline throughput by as much as a factor of two at a
modest cost. Conceptual design, engineering analyses, and fabrication steps are outlined.
Directly water-cooled crystal development for SPring-8 bending magnet beamlines
Author(s):
Kunikazu Takeshita;
Shunji Goto;
Tetsuya Ishikawa
Show Abstract
The directly water-cooled first crystal of the SPring-8 standard monochromator for bending magnet beamlines has been
developed. Thanks to the bonding technique, the performance of the new crystal has been improved without decreasing
the cooling efficiency. The finite element analyses show the deformation of the crystal by the hydraulic pressure and by
the crystal clamping is negligible small, which were dominated for the previous crystal. Both Si(111) and Si(311) crystal
were evaluated in SPring-8 beamlines, the deformation induced while the bonding process is comparable to the thermal
deformation. and long-term endurance test shows the lifetime of the O-ring becomes long because they are not on the
direct path of the SR beam. Although the overall performance is insufficient, much improvement was shown.
Measurement of thermal contact conductance of SPring-8 beamline components
Author(s):
Tetsuro Mochizuki;
Haruhiko Ohashi;
Mutsumi Sano;
Sunao Takahashi;
Shunji Goto
Show Abstract
Direct cooling is adopted for most high heat load components in SPring-8 beamlines. On the other hand, contact cooling
is employed for some components such as a graphite filter, aluminum filter, mirror, and cryogenic monochromator
silicon crystal. For the thermal design of the contact cooling components, it is important to obtain reliable thermal
contact conductance value. The conductance depends on many parameters such as the surface materials, surface
roughness, flatness of the surface, interstitial materials, temperature of the contact surface, and contact pressure. An
experimental setup is fablicated to measure the conductance at liquid nitrogen temperature and room temperature. The
thermal contact conductance of a Si-Cu interface and that of a Si-In-Cu interface are measured at cryogenic temperature
at contact pressures ranging from 0.1-1.1 MPa. The conductance of an Al-Cu interface and that of a graphite-Cu interface
are measured using gold and silver foils as interstitial materials. The measurements are performed at room temperature
and at pressures ranging from 0.5-4 MPa. The experimental setup and the results obtained are presented.
Performance of newly developed Mg/SiC multilayer mirrors
Author(s):
Takenori Toyota;
Go Murakami;
Kazuo Yoshioka;
Ichiro Yoshikawa
Show Abstract
A multilayer coating mirror of Mo/Si is usually used for space science in the spectral range of extreme ultraviolet (EUV),
especially for He-II (30.4 nm) radiation, because it is highly stable under vacuum and atmosphere. It has the fairly high
reflectivity of 15-20%. However, the space science community needs the coating of higher reflectivity at 30.4 nm
radiation for the future satellite missions, especially for the small satellite (to reduce the size of optics). In this work, for
developing a new multilayer mirror for He-II radiation, we report the performance of a multilayer consisting of Mg/SiC
and the aging in reflectivity under atmosphere and vacuum.
High-performance multilayer coatings for 106 nm
Author(s):
Elena Yu Taracheva;
Sergiy Yulin;
Torsten Feigl;
Norbert Kaiser
Show Abstract
High-reflective multilayer coatings were designed at the wavelength of 106 nm and deposited by different deposition
technologies (magnetron sputtering, thermal and e-beam evaporations). Various capping layers were suggested to protect
Al/LiF coatings against the surface degradation. The microstructure and the surface morphology of all coatings were
studied by Small Angle X-ray Reflectometry (SAXR) and Atomic Force Microscopy (AFM) methods. The optical
properties were characterized in the Vacuum Ultraviolet (VUV) spectral range by VUV-reflectometry. Finally, the aging
stability of coatings was studied.
Micro-optics test bench at the ESRF
Author(s):
A. A. Snigirev;
R. Hustache;
P. Duboc;
J.-Y. Massonnat;
L. Claustre;
P. Van Vaerenbergh;
I. Snigireva;
M. Grigoriev;
V. Yunkin
Show Abstract
A versatile instrument capable of high resolution X-ray optics characterization has been implemented at the ESRF. The
Micro-Optics Test Bench (MOTB) is installed in EH2 of BM5 and is located 55 meters from the tangent point of a
dipole magnet. Substantial gain has been demonstrated in the characterization of microfocusing and imaging optical
elements, including diffractive, refractive and reflective optics.
High-energy-resolution monochromator for nuclear resonant scattering of synchrotron radiation by Te-125 at 35.49 keV
Author(s):
Yasuhiko Imai;
Yoshitaka Yoda;
Shinji Kitao;
Ryo Masuda;
Satoshi Higashitaniguchi;
Chika Inaba;
Makoto Seto
Show Abstract
We have developed a high-resolution monochromator (HRM) for the measurement of nuclear resonant scattering (NRS)
of synchrotron radiation by Te-125 at 35.49 keV using the backscattering of sapphire (9 1 -10 68). HRMs for nuclei with
excitation energies less than 30 keV have been successfully developed using high angle diffractions by silicon crystals.
Nearly perfect silicon crystal, however, is not suitable for high efficient HRMs at higher energy regions because the
symmetry of the crystal structure is high and the Debye-temperature is low. Therefore, we used high quality synthetic
sapphire crystal, which has low symmetry of crystal structure and high Debye-temperature. The temperature of the
crystal was precisely controlled around 218 K to diffract synchrotron radiation with a Bragg angle of π/2 - 0.52 mrad.
Energy was tuned by changing the crystal temperature under the condition of constant diffraction angle. Energy
resolution was measured by detecting nuclear forward scattering by Te-125 in enriched TeO2. The relative energy
resolution of 2.1×10-7 is achieved, that is 7.5 meV in energy bandwidth. This HRM opens studies on element-specific
dynamics and electronic state of substances containing Te-125.