The future space X-ray astronomy imaging missions require very large collecting areas at still fine angular resolution and reasonable weight. The novel space Xray optics substrates such as Silicon wafers and thin thermally formed glass enable wide applications of precise and very light weight (volume densities 2.3 to 2.5 gcm<sup>-3</sup>) optics. The recent status of novel technologies as well as developed test samples with emphasis on precise optical surfaces based on novel materials and their space applications will be presented and discussed.
We report on the progress in innovative X-ray mirror development with focus on requirements of future X-ray astronomy space projects. Various future projects in X-ray astronomy and astrophysics will require large lightweight but highly accurate segments with multiple thin shells or foils. The large Wolter 1 grazing incidence multiple mirror arrays, the Kirkpatrick-Baez modules, as well as the large Lobster-Eye X-ray telescope modules in Schmidt arrangement may serve as examples. All these space projects will require high quality and light segmented shells (shaped, bent or flat foils) with high X-ray reflectivity and excellent mechanical stability.
The LOBSTER telescopes are based on the optical arrangement of the lobster eye. The main difference from classical X-ray space telescopes in wide use is the very large field of view while the use of optics results in higher efficiency if compared with detectors without optics. Recent innovative technologies have enabled to design, to develop and to test first prototypes. They will provide deep sensitive survey of the sky in X-rays for the first time which is essential for both long-term monitoring of celestial high-energy sources as well as in understanding transient phenomena. The technology is now ready for applications in space.
The future space X-ray astronomy imaging missions require very large collecting areas at still fine angular resolution and reasonable weight. The novel substrates for X-ray mirrors such as Silicon wafers and thin thermally formed glass enable wide applications of precise and very light weight (volume densities 2.3 to 2.5 gcm<sup>-3</sup>) optics. The recent status of novel technologies as well as developed test samples with emphasis on precise optical surfaces based on novel materials and their space applications is presented and discussed.
A number of soft x-ray / water window laboratory sources is being developed by many groups including the group at CTU. This paper presents simulations and critical parameter estimates for lensless imaging using the laboratory sources, especially the capillary discharge source being developed by our group.<sup>1</sup> Water window lensless imaging is demonstrated to be generally feasible with high repetition laboratory sources.
A novel design of X-ray optical system - concentrator for astrophysical rocket experiment is investigated. The proposed system is
based on four modules with Kirkpatrick-Baez (KB) configuration allowing usage of multi-foil mirrors arranged to parabolic profile.
The KB modules are supplemented by rotationally symmetrical parabolic segments. This X-ray optical system effectively uses
a circular aperture. The KB modules are placed in four quadrants while the segments are set into a Cartesian cross between
the KB modules. Studied optical system is under consideration for the student rocket experiment of University of Colorado that
should verify function of NIST’s energy-dispersive detector based on Transition Edge Sensors (TES microcalorimeters).
Space X-ray imaging telescopes have delivered unique observations that have been significantly contributing to many important discoveries of current astrophysics. For future telescopes with a larger collecting area and a better angular resolution, the limiting factor is their X-ray reflecting mirror array. Therefore, for a successful construction of future lightweight and highly reflecting X-ray mirrors, new cost-effective technologies and progressive materials are needed. Currently, the very promising materials are silicon foils which are commercially produced on a large scale. We focused on the plastic deformation of thin monocrystalline silicon foils, which was necessary for the precise thermal forming of the foils to 3D shapes. To achieve the plastic deformation, we applied forced slumping at temperatures from 1200 to 1400°C. The final shapes and the surface quality of the foils were measured using a Taylor Hobson contact profilometer and examined with an Atomic Forced Microscopy. We studied the effects of temperature, applied slumping force, heattreatment time, crystal orientation, and furnace atmosphere on the shape and surface quality of the formed foils.
In this work photoionized plasmas were created by irradiation of He, Ne and Ar gases with a focused EUV beam from one of two laser-plasma sources employing Nd:YAG laser systems of different parameters. First of them was a 10-Hz laser-plasma EUV source, based on a double-stream gas-puff target, irradiated with the 3-ns/0.8J laser pulse. EUV radiation in this case was focused using a gold-plated grazing incidence ellipsoidal collector in the wavelength range λ = 9÷70 nm. The most intense emission was in the relatively narrow spectral region centred at λ = 11 ± 1 nm. The second source was based on a 10 ns/10 J/10 Hz laser system. In this case EUV radiation was focused using a gold-plated grazing incidence multifoil collector or a Mo-coated ellipsoidal collector. The most intense emission in this case was in the 5 ÷ 15 nm spectral region. Radiation fluence ranged from 60 mJ/cm<sup>2</sup> to 400 mJ/cm<sup>2</sup>. Different gases were injected into the interaction region, perpendicularly to an optical axis of the irradiation system, using an auxiliary gas puff valve. Irradiation of the gases resulted in ionization and excitation of atoms and ions. Spectra in EUV range were measured using a grazing incidence, flat-field spectrometer (McPherson Model 251), equipped with a 450 lines/mm toroidal grating. In all cases the most intense emission lines were assigned to singly charged ions. The other emission lines belong to atoms or doubly charged ions. The spectra were excited in low density gases of the order of 1 ÷ 10% atmospheric density.
We developed a non-contact method for in-situ monitoring of the thermal slumping of glass and silicone foils to optimize
this technology for the production of high quality mirrors for large aperture x-ray space telescopes. The telescope's
crucial part is a high throughput, heavily nested mirror array with the angular resolution better than 5 arcsec. Its
construction requires precise and light-weight segmented optics with surface micro-roughness on the order of 0.1 nm.
Promising materials are glass or silicon foils shaped by thermal forming. The desired parameters can be achieved only
through optimizing the slumping process. We monitored the slumping by taking the snapshots of the shapes every five
minutes at constant temperature and the final shapes we measured with the Taylor Hobson profilometer. The shapes were
parabolic and the deviations from a circle had the peak-to-valley values of 20-30 μm. The observed hot plastic
deformation of the foils was controlled by viscous flow. We calculated and plotted the relations between the middle part
deflection, viscosity, and heat-treatment time. These relations have been utilized for the development of a numerical
model enabling computer simulation. By the simulation, we verify the material's properties and generate new data for
the thorough optimization of the slumping process.
ELI-Beamlines will be a high-energy, repetition-rate laser pillar of the ELI (Extreme Light Infrastructure) project. It will
be an international facility for both academic and applied research, slated to provide user capability since the beginning
of 2016. The main objective of the ELI-Beamlines Project is delivery of ultra-short high-energy pulses for the
generation and applications of high-brightness X-ray sources and accelerated particles. The laser system will be
delivering pulses with length ranging between 10 and 150 fs and will provide high-energy petawatt and 10-PW peak
powers. For high-field physics experiments it will be able to provide focused intensities attaining 10<sup>24</sup> Wcm<sup>-2</sup>, while this
value can be upgraded in a later phase without the need to upgrade the building infrastructure. In this paper we describe
the overall conception and layout of the designed ELI-Beamlines facility, and review some essential elements of the
The replication technology originally developed for astronomical X-ray optics can be also effectively applied for
laboratory mirrors with small apertures, even below few mm. Grazing incidence micromirrors of ellipsoidal or parabolic
shape with apertures below 1 mm have numerous potential applications in many areas of applied physics, molecular
biology and material research, including synchrotron. One of the most important applications of such optics is in its
combination with microfocus X-ray generator. Extremely intense collimated or focused high-quality X-ray beams from
tabletop equipment can be obtained in this way. It is shown that though developed primarily for macromolecular
crystallography, this combination gave excellent results also in other fields of science and technology. Computer raytracing
and experimental data characterizing mirror and X-ray beam parameters in typical applications are also presented.
Two experimental modules of small X-ray telescopes based on the Lobster eye X-ray optics are presented. These
modules are regarded to use for x-ray astronomy applications in space. At this time, the optical tests of these
modules have been performed. Results of these tests are presented.
Lobster eye optics, as a wide field of view imaging system, is perfectly suited for x-ray astronomy but can be
useful also in the lab. This paper presents a brief overview of the technologies developed in our group, where
the glass and silicon mirrors are used to built up the Schmidt lobster eye design and mainly discuss the mirror
design consequences on the resulting imaging properties of the system. Corrections of various image distortions
and imperfections, either geometric, spectral or temporal in case of scanning observations have to be applied
in order to get a valuable instrument. Several image processing methods are discussed and its strengths and
weaknesses are shown for both astronomy and laboratory experiments.
Laser plasma source in WAT, Poland, is used as the source of EUV radiation for lithography and illumination
of biological samples. The source has to be equipped with a complementary condensor with the goal of having
a higher peak intensity than using current systems and moreover with the ability to illuminate larger areas
homogeneously. The work concentrates on the analysis and design process of the optics based on the known
source parameters, namely typical spectra, angular and intensity distributions and other constraints. Further,
the question of illuminating the samples via multi shot approach by shifting the sample is discussed and estimates
on the optimal sample shift in between two shots are explained.
Compound refractive lenses (CRL), consisting of a lot number in-line concave microlenses made of low-Z material were studied. Lenses with focal length 109 mm and 41 mm for 8-keV X-rays, microfocus X-ray tube and X-ray CCD camera were used in experiments. Obtained images show intensity distribution of magnified microfocus X-ray source
focal spot. Within the experiments, one lens was also used as an objective lens of the X-ray microscope, where the copper anode X-ray microfocus tube served as a source. Magnified images of gold mesh with 5 microns bars were obtained. Theoretical limits of CRL and experimental results are discussed.
We report on recent progress with development of astronomical X-ray optics based on thermally formed glass foils
and on bent Si wafers. Experiments with thermal glass forming have continued adding wider range of evaluated
and optimized parameters. Recent efforts with Si wafers have been focused on their quality improvements such
as flatness and thickness uniformity in order to better meet the requirements of future X-ray astronomy projects
applications, as well as on study of their surface quality, defects analysis, and methods for its reproducible measurement.
The role of substrates quality in performance of final mirror arrays, as required by large future space X-ray astronomy
experiments was also studied. The problem of increasing size of Si wafers, required for some X-ray optics applications,
is also addressed. First results of irradiation tests of selected substrates are also reported and discussed.
The precisely shaped glass sheets and Si wafers are generally considered as the most promising substrates for future
large space astronomical X-ray telescopes. Both approaches have demonstrated promising results obtained in the
course of last years. In this contribution, we report on continued systematic efforts and analysis in precise shaping of
thin glass sheets as well as Si wafers. New results will be briefly presented and discussed. For Si wafers, recent
efforts focus also on improving the intrinsic quality of the slices to better meet the high requirements of future space
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.
A single photon of EUV radiation carries enough energy to break any chemical bond or excite electrons from inner
atomic shells. It means that the radiation regardless of its intensity can modify chemical structure of molecules. It is the
reason that the radiation even with low intensity can cause fragmentation of long chains of organic materials and
desorption of small parts from their surface. In this work interaction of EUV radiation with inorganic materials was
investigated. Different inorganic samples were irradiated with a 10 Hz laser - plasma EUV source based on a gas puff
target. The radiation was focused on a sample surface using a lobster eye collector. Radiation fluence at the surface
reached 30 mJ/cm<sup>2</sup> within a wavelength range 7 - 20 nm. In most cases there was no surface damage even after several
minutes of irradiation. In some cases there could be noticed discolouration of an irradiated surface or evidences of
thermal effects. In most cases however luminescent and scattered radiation was observed. The luminescent radiation was
emitted in different wavelength ranges. It was recorded in a visible range of radiation and also in a wide wavelength
range including UV, VUV and EUV. The radiation was especially intense in a case of non-metallic chemical compounds.
We present the recent progress in high intensity micro focused EUV beam generation. Ellipsoidal thin glass foils were used in Multi-foil optical systems for focusing radiation in 50 eV to 150 eV energy band from gas-puff laser plasma source. Multifoil optic (MFO) condenser was designed and tested for applications with Xe laser plasma gas-puff source. High intensity EUV beam focal spot was recorded, analyzed and compared with theoretical results from computer ray-tracing. Direct EUV lithography using radiation induced decomposition and ablation of TEFLON was studied.
The thermally formed thin glass foils and optically shaped Si wafers are considered to belong to the most promising
technologies for future large space X-ray telescopes. We present and discuss the recent progress in these technologies, as
well as properties of test mirrors produced and tested. For both technologies, both flat and curved samples have been
produced and tested. The achieved profile accuracy is of order of 1 micrometer or better, while the bending technologies
maintain the intrinsic fine surface microroughness of substrates (better than 0.5 nm for glass and around 0.1 nm for Si
The future large space X-ray telescopes in study (such as the ESAs XEUS) require novel approaches and innovative lightweight technologies. Although there are several alternative possibilities, in general the shaped thin glass foils and shaped Si wafers are considered to belong to the most promising ones. We present and discuss the recent progress in these technologies, as well as properties of test mirrors produced and tested. For both technologies, both flat and curved samples have been produced and tested. The achieved profile accuracy is of order of 1 micrometer or better, while the bending technologies maintain the intrinsic fine surface microroughness of substrates (better than 0.5 nm).
We present a review of a hybrid Lobster optic built up of a mixture of standard Lobster Eye geometry and parabolically bent mirrors. This design has better angular resolution in one direction while still having a wide field of view in the other. We have performed some computer simulations and comparisons with standard LE optic, hence we can discuss the advantages and/or disadvantages of such design as well as possible operating modes, especially in the case of X-ray all-sky monitor. Additionally, we are going to show first laboratory samples of parabolically bent mirrors for hybrid lobster array which were produced using several different technologies.
We propose an X-ray all-sky monitor sensitive in soft X-ray band with the potential to work up to ~ 10 keV. The limiting flux of the proposed system is ~ 10<sup>-12</sup> erg/s/cm<sup>2</sup> and the angular resolution ~ 4 arc min. The system consists of a number of wide-field modules based on the Multi-Foil Optics.
We report on innovative X-ray mirror technologies with focus on requirements of future X-ray astronomy space projects. Various future projects in X-ray astronomy and astrophysics will require large light-weight but highly accurate segments with multiple thin shells or foils. The large Wolter 1 grazing incidence multiple mirror arrays, the Kirkpatrick-Baez modules, as well as the large Lobster-Eye X-ray telescope modules in Schmidt arrangement may serve as examples. All these space projects will require high quality and light segmented shells (shaped, bent or flat foils) with high X-ray reflectivity and excellent mechanical stability.
We describe and discuss astronomical LOBSTER EYE X-ray telescopes based on Multi Foil Optics including recent results of the development and tests of advanced laboratory samples. An alternative proposal for a space experiment based on this optics - Lobster All Sky Monitor - is also briefly presented and discussed.
The wide field Lobster Eye telescopes are expected to play an important role in future X-ray astrophysics missions and analyses. The advanced prototypes of Lobster Eye optics modules of various sizes and various arrangements confirm the justification of space applications of theses innovative devices. Recently, both very small LE Schmidt prototypes (3x3 mm based on 0.03 mm foils spaced at 0.07 mm) as well as large (300 x 300 mm based on 0.75 mm foils spaced at 10.8 mm) have been designed, developed and tested. Advanced technologies for additional surface layers have been also investigated. The extended computer simulations confirm the high performance and scientific justification of the space born Lobster Eye telescope experiment. Emphasis was given on the alternative approach for the future ESA projects. We describe and discuss here the recent progress in the design, simulations, development and tests of advanced multifoil X-ray telescope prototypes.
We describe and discuss the LOBSTER EYE X-ray telescope project including recent results of the development and tests of advanced telescope prototypes. They include both very small (3 × 3 mm) as well as large (300 × 300 mm) Schmidt lenses. Considerations for a space experiment on a small scientific satellite of a Nadezhda type are also discussed.