Focusing optics for hard x-/soft gamma-rays (above 100 keV) are in a development phase. One promising method is represented by the Laue lens technology that has already been validated through on-ground prototypes and balloon tests. Laue lens optics will be an outstanding tool for observing weak sources in a notably short integration time thanks to the excellent sensitivity they can provide. Such performances has been further increased with the employ of cylindrical bent crystals that are capable to dramatically narrow the Laue lens Point Spread Function (PSF). One aspect that is under investigation is the image aberrations for off-axis sources. This fact limits the Field of View (FoV) of a Laue lens to few arcmin. The employ of bent crystals in double diffraction configuration would reduce the mentioned aberration, increasing the FoV of the resulting Laue lens. Double diffraction crystals would represent an extension to hundreds of keV of the Lobster Eye (LE) principles that is well tested for focusing < 10 keV photons. We investigate pros and cons of the double diffraction configuration with respect to the single diffraction through Monte Carlo simulations and we compare their performances in terms of efficiency, PSF, pass-band and effective area. We also present preliminary tests performed at the LARIX facility to evaluate the technical feasibility of crystals with the aforementioned characteristics.
The progress of X-ray Optics joint research activity of the European Union Horizon 2020 AHEAD project is presented here covering the X-ray optic technologies that are currently being worked on in Europe. These are the Kirkpatrick Baez, lobster eye micropore (SVOM, SMILE), slumped glass, and silicon pore (ATHENA, ARCUS) optics technologies. In this activity detailed comparisons of the measurements, of the different optics produced by the participating optics groups, obtained mainly at the MPEs PANTER X-ray test facility, are compared with simulations. In preparation for the ATHENA mission a study has been made to design the BEaTRiX X-ray test facility for testing individual silicon pore optics mirror modules, and the realization of the facility is now on going. A zone plate collimating optics developed for PANTER is being studied, optimized, and tested at PANTER. This zone plate will be used for characterising a high quality optics module in a parallel beam to verify the BEaTriX performance. Several of the measurements and selected results are presented here.
The X-ray optics is a key element of space X-ray telescopes, as well as other X-ray imaging instruments. The grazing incidence X-ray lenses represent the important class of X-ray optics. Most of grazing incidence (reflective) X-ray imaging systems used in astronomy but also in other (laboratory) applications are based on the Wolter 1 (or modified) arrangement. But there are also other designs and configurations proposed, used and considered for future applications both in space and in laboratory. The Kirkpatrick-Baez (K-B) lenses as well as various types of Lobster-Eye optics and MCP/Micropore optics serve as an example. Analogously to Wolter lenses, the X-rays are mostly reflected twice in these systems to create focal images. Various future projects in X-ray astronomy and astrophysics will require large segments with multiple thin shells or foils. The large Kirkpatrick-Baez modules, as well as the large Lobster-Eye X-ray telescope modules in Schmidt arrangement may serve as examples. All related space projects will require high quality and light segmented shells (bent or flat foils) with high X-ray reflectivity and excellent mechanical stability. The Multi Foil Optics (MFO) approach represent a promising alternative for both LE and K-B X-ray optical modules. Several types of reflecting substrates may be considered for these applications, with emphasis on thin float glass sheets and, more recently, high quality silicon wafers. This confirms the importance of non-Wolter X-ray optics designs for the future. The alternative designs require novel reflective substrates which are also discussed in the paper.
Applications of wide field Lobster Eye X ray telescopes are presented and discussed. The wide field X ray optics was originally proposed for use in X-ray astronomy, but there are numerous other application areas as well.
Schmidt lobster eye multi-foil optics allows high field of view and it can have small mass and dimensions. It makes the optic usable on small low-cost satellite mission that would permanently monitor selected sky area(s). In the paper, possible optical designs are presented. Presented designs are derived of existing optics specimen, therefore they should be technically feasible.
Analytical equations describing lobster eye optical parameters on dependence on its geometric parameters are presented. The paper partially gives review of main previously known results. At next, the paper gives new results discussing parameters, that were not included to previously published models but may be significant. The results are applicable for a Schmidt as well as for an Angel lobster eye and for some related multi-foil systems.
This work addresses the issue of X-ray monitoring for astrophysical applications. The proposed wide-field optical system
has not been used in space yet. The proposed novel approach is based on the use of 1D "Lobster eye" optics in
combination with Timepix X-ray detector in the energy range 3 - 40 keV. The proposed project includes theoretical
study and a functional sample of the Timepix X-ray detector with multifoil wide-field X-ray "Lobster eye" optics. Using
optics to focus X-rays on a detector is the only solution in cases the intensity of impinging X-ray radiation is below the
sensitivity of the detector, e.g. while monitoring astrophysical objects in space, or phenomena in the Earth's atmosphere.
The optical system could be used in a student rocket experiment at University of Colorado. Ideal opportunity is to extend
the CubeSat of Pennsylvania State University with the hard X-ray telescope demonstrator consisting of an optical
module and Timepix detector.
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).
We present the idea of a low-cost satellite providing permanent monitoring of X-ray binaries. These systems contain a compact object (a neutron star or a black hole) accreting matter from a donor companion. They concentrate in the vicinity of the Galactic plane and toward the center of the Galaxy. It therefore appears very advantageous to point the telescope toward the Galactic center. The strong activity of X-ray binaries with non-predictable episodes of brightening suggests that we can obtain meaningful and physically important information even by a study using a small, inexpensive satellite. The proposed spacecraft can be of the nano-satellite class. We propose Schmidt lobster optics for this satellite. The results of experimental tests of the specimen of such optics show that the mission is feasible.
A method simplifying the common ray-tracing procedure is presented. In some specific cases, to perform numerical simulations of reflective optical system, not traces of all rays are necessary to simulate but only of few ones. Therefore, the presented method is extremely effective. Moreover, to simplify the equations, the specific mathematical formalism is used. Because only few simple equations are used only, the program code can be simple as well.
The future of X-ray astronomy requires heavily nested large area X-ray mirrors with arcsecond angular resolution in future X-ray astrophysics experiments. Despite of promising results of several exploited technologies during the past decade, it is not demonstrated yet that these technologies will provide the angular resolutions better than few arcsec. The alternative approach is the method of active X-ray optics. In addition, active approaches based on computer control may be applied directly during manufacturing of advanced X-ray optics elements, such as substrate slumping. In this report, we present and discuss preliminary results of X-ray tests of various modules in active X-ray optics arrangements.
In this work, we investigate a novel design of optical system for astrophysics. In addition, a new testing method in the X-ray laboratory was verified. The proposed optical system is composed of modules with Kirkpatrick-Baez configuration allowing usage of multi-foil mirrors arranged to parabolic profile. This system effectively uses a circular aperture, which is divided into petals. Individual petals consist of diagonally oriented KB cells with common focus. The hybrid optical system includes a set of rotationally symmetrical parabolic mirrors to achieve higher reflection efficiency of harder X-rays. New results are presented.
In this work, we investigate a novel design of optical system for astrophysics. In addition, a new
testing method in the X-ray laboratory was verified. The proposed optical system is composed of modules with
Kirkpatrick-Baez configuration allowing usage of multi-foil mirrors arranged along a parabolic profile. This
system effectively uses a circular aperture, which is divided into petals. Individual petals consist of diagonally
oriented KB cells with a common focus. This optical system can be improved by a set of nested rotationally
symmetric X-ray mirrors in order to achieve higher reflection efficiency in harder part of considered spectrum.
Star cameras represent a well-known class of attitude determination sensors. At this time, they achieve excellent
accuracy within arc-seconds. However their size, mass, power, and cost make current commercial versions
unacceptable for use on nano-satellites. Here, the concept of developing a small star camera with very modest
accuracy requirements for future nano-satellite missions is studied. A small commercial cmos sensor with
minimal commercial optics is presented. The cmos imager has an active array area of 5.7 × 4.3mm, with a
focal length of 6mm and an aperture ratio of 1.4. This camera's field-of-view is approximately 50 × 40 degrees
and can capture stars of magnitudes smaller than 3 with acquisition times of 100ms. The accuracy of attitude
determination methods using data collected by this camera was tested by taking photos of the night sky under
terrestrial conditions. The camera attitude was determined using offline image processing and star field attitude
determination algorithms. Preliminary attitude accuracy results were determined and they are presented.
The Lobster eye design for a grazing incidence X-ray optics provides wide field of view of the order of many
degrees, for this reason it would be a convenient approach for the construction of space X-ray monitors. In
this paper, we compare previously reported measurements of prototype lobster eye X-ray optics called P-25
with computer simulations and discuss differences between the theoretical end experimentally obtained results.
Usability of this prototype lobster eye and manufacturing technology for the nano-satellite mission is assessed.
The specific scientific goals are proposed.
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.