Lidé

Ing. Veronika Stieglitz, Ph.D.

Všechny publikace

Experimental astronomical observation using a lobster eye optics

  • DOI: 10.1002/asna.20230106
  • Odkaz: https://doi.org/10.1002/asna.20230106
  • Pracoviště: Katedra radioelektroniky
  • Anotace:
    A lobster eye (LE) is a wide-field type of X-ray optics, which provides a large field of view at the expense of angular resolution. The optics presented in this paper are the LE optics in Schmidt arrangement made from glass sheets with golden reflective coatings. It was used as a scientific payload on the WRXR rocket experiment. Before the mission itself, the optics was tested on ground to obtain more information about its behavior. Part of these tests were several nights of observation at the Ondrejov observatory. We used the optics in combination with a CMOS camera to acquire images in visible light of various bright sources in the sky. In order to enable long-time exposures, the robotic mount of the BART telescope was used. The goal of this experiment was to confirm the focal length of the optics using a source at infinity, and to show how the optics, designed for X-ray observations, performs in visible light. This brief article describes the methods used for evaluation and presents and discusses the results obtained within the night observation experiment.

Testing of lobster-eye type telescopes with X-rays and visible light

  • DOI: 10.1117/12.2665429
  • Odkaz: https://doi.org/10.1117/12.2665429
  • Pracoviště: Katedra radioelektroniky
  • Anotace:
    Reflective coatings for astronomical X-ray optics were developed at the “Aschaffenburg Competence Center for Astronomical and Space Instrumentation” (ACCASI) since several years. As part of a Bavarian-Czech cooperation between the Technical University of Aschaffenburg and the Czech Technical University of Prague, now two mechanically identical telescopes were built. One telescope optic was equipped with conventional gold-coated mirrors, manufactured by the Czech project partners. The 34 X-ray mirrors of the second telescope use an innovative coating system made of chromium and iridium, which was applied at the Aschaffenburg coating laboratory. Both telescopes are designed according to the bionic principle of a reflecting lobster eye. The optics works with two consecutive reflections on mutually perpendicular mirror surfaces. This enables a large field of view with many square degrees in diameter, which, however, comes at the price of a reduced angular resolution. An extensive X-ray characterization of these telescopes was carried out at the PANTER test facility of MPE, which simulates parallel starlight incident on the telescopes. The telescopes have an angular resolution of about 4 arc minutes in X-rays and a focal length of about 2 meters. Furthermore, the used X-ray mirrors reflect and focus visible light as well and this functionality in the optical regime was checked in laboratory tests. Now another test campaign was done to examine the telescope resolution for real objects of the visible sky and the imaging properties for star constellations. Such functional tests by observing astronomical objects of the visible sky may simplify and accelerate the development of X-ray telescopes for satellite applications.

Characterisation of X-ray mirrors based on chromium-iridium tri-layer coatings

  • Autoři: Doehring, T., Stollenwerk, M., Stadtmueller, J., Zeising, S., Flachs, D., Ing. Veronika Stieglitz, Ph.D.,
  • Publikace: Proc. SPIE 11776, EUV and X-ray Optics, Sources, and Instrumentation. Bellingham WA: The International Society for Optical Engineering (SPIE), 2021. Proceedings of SPIE. vol. 11776. ISSN 0277-786X. ISBN 978-1-5106-4386-4.
  • Rok: 2021
  • DOI: 10.1117/12.2592551
  • Odkaz: https://doi.org/10.1117/12.2592551
  • Pracoviště: Katedra radioelektroniky
  • Anotace:
    Iridium-based layer systems are highly effective mirror coatings for space-born X-ray telescopes. During the recent years, Aschaffenburg University of Applied Sciences and its partners developed stress compensated chromium-iridium coatings for such astronomical applications, using chromium as an adhesive layer between iridium reflective layer and mirror substrate. However, there was room for improvement: To overcome the disturbing reflectivity reduction of the iridium absorption edge around 2 keV photon energy, thin overcoat layers of chromium are applied in addition now. This layer system has been analyzed by atomic force microscopy and transmission electron microscopy images. Furthermore, the reflectivity of such innovative X-ray mirrors based on chromium-iridium tri-layer coatings was recently measured at PTB's four-crystal monochromator beamline at the synchrotron radiation facility BESSY II. The experimental results, obtained for photon energies between 1.9 keV and 11 keV at two grazing incidence angles (0.6 degree and 0.9 degree) and their comparison with corresponding simulations are presented in this contribution. When compared to simulations of pure iridium coatings, a significantly higher reflectivity was achieved especially in the soft X-ray regime between 2 keV and 4 keV. Such chromium-iridium tri-layer coatings have high potential to increase the effective area for X-ray telescopes in Lobster Eye Design, for Wolter-I type X-ray optics, and for silicon pore optics as considered for the ATHENA telescope of the European Space Agency.

Lobster eye type X-ray telescope with chromium-iridium coated tri-layer mirrors

  • Autoři: Ing. Veronika Stieglitz, Ph.D., Döhring, T., Stollenwerk, M., Stadtmüller, J., Maršíková, V., prof. RNDr. René Hudec, CSc., Flachs, D., Burwitz, V., Hartner, G., Rukdee, S., Müller, T., Inneman, A., Schmidt, T., Klementova, M., Zeising, S., Langmeier, A.
  • Publikace: Proc. SPIE 11776, EUV and X-ray Optics, Sources, and Instrumentation. Bellingham WA: The International Society for Optical Engineering (SPIE), 2021. Proceedings of SPIE. vol. 11776. ISSN 0277-786X. ISBN 978-1-5106-4386-4.
  • Rok: 2021
  • DOI: 10.1117/12.2589266
  • Odkaz: https://doi.org/10.1117/12.2589266
  • Pracoviště: Katedra radioelektroniky
  • Anotace:
    For space-born astronomical X-ray telescopes, iridium-based reflective layer systems are known as highly effective mirrors coatings. During the recent years, Aschaffenburg University of Applied Sciences and the Czech Technical University in Prague jointly developed stress compensated chromium-iridium coatings for this application. To overcome the disturbing re ectivity reduction of the iridium absorption edge around 2 keV photon energy, thin overcoat layers of chromium were applied in addition. Now a prototype of a wide-field, imaging X-ray telescope of Lobster Eye type is assembled at the company RIGAKU. For this purpose a small series of 34 mirrors based on 100 x 50 mm semiconductor grade silicon substrates has been coated at Aschaffenburg University. The applied tri-layer system consists of a stack of 40 nm chromium, which act as adhesive layer and compensates layer stress, a 30 nm iridium thick reflective layer, and an additional overcoat layer of 6 nm chromium. This layer system have been analysed by AFM and TEM images. The mirrors are assembled into an aluminium frame to build a 2D Lobster Eye type telescope. The designed focal length of this wide field X-ray telescope is two meter. To study the performance of the tri-layer coating system, a twin LE telescope with convenient gold coatings was manufactured also. Performance measurements of both telescopes and under same conditions are planned at the PANTER test facility at the Max-Planck Institute for Extraterrestrial Physics. First experimental results, their comparison with theoretical simulations and the comparison between both models will be presented in this contribution.

In-Orbit Commissioning of Czech Nanosatellite VZLUSAT-1 for the QB50 Mission with a Demonstrator of a Miniaturised Lobster-Eye X-Ray Telescope and Radiation Shielding Composite Materials

  • DOI: 10.1007/s11214-019-0589-7
  • Odkaz: https://doi.org/10.1007/s11214-019-0589-7
  • Pracoviště: Katedra fyziky, Katedra radioelektroniky, Multirobotické systémy
  • Anotace:
    This paper presents the results of in-orbit commissioning of the first Czech technological CubeSat satellite of VZLUSAT-1. The 2U nanosatellite was designed and built during the 2013 to 2016 period. It was successfully launched into Low Earth Orbit of 505 km altitude on June 23, 2017, as part of international mission QB50 onboard a PSLV C38 launch vehicle. The satellite was developed in the Czech Republic by the Czech Aerospace Research Centre, in cooperation with Czech industrial partners and universities. The nanosatellite has three main payloads. The housing is made of a composite material which serves as a structural and radiation shielding material. A novel miniaturized X-Ray telescope with lobster-eye optics and an embedded Timepix detector represents the CubeSat’s scientific payload. The telescope has a wide field of view. VZLUSAT-1 also carries the FIPEX scientific instrument as part of the QB50 mission for measuring the molecular and atomic oxygen concentration in the upper atmosphere.

Multifoil optics for rocket experiments

  • DOI: 10.1117/12.2525541
  • Odkaz: https://doi.org/10.1117/12.2525541
  • Pracoviště: Katedra radioelektroniky, Multirobotické systémy
  • Anotace:
    A novel design of x-ray optical system wide field telescope for astrophysical rocket experiments is investigated and tested in real space flight experiment. The proposed system is based on 1D and 2D modules with Schmidt Lobster Eye (LE) configuration allowing usage of multi-foil mirrors arranged to Schmidt profile.

REX le X-ray telescope experiment overview

  • DOI: 10.1117/12.2527288
  • Odkaz: https://doi.org/10.1117/12.2527288
  • Pracoviště: Katedra radioelektroniky, Multirobotické systémy
  • Anotace:
    The paper summarizes the Rocket EXperiment (REX) Lobster Eye (LE) X-ray Telescope payload results. The experiment was performed by the PennState University with X-ray spectroscope on board a Water Recovery X-Ray Rocket (WRXR) launched on 4th April, 2018. The secondary payload was the REX LE X-ray Telescope. The REX LE X-ray telescope consists of two X-ray telescopes with one-dimensional (1D) and two-dimensional (2D) optics, a visible-light camera and an IR grid-eye. The primary structure consists of a metal housing for the optics and a carbon fiber baffle with the Timepix sensors mounted at the end. The observation data from the experiment are briefly presented and discussed.

Multi-Foil X-ray optics tests at PANTER: Preliminary results

  • Pracoviště: Katedra radioelektroniky
  • Anotace:
    We present and discuss preliminary test results performed with selected modules of Multi-Foil X-ray Optics in the MPE PANTER X{ray test facility. Three X-ray optics Multi{Foil modules were tested, namely 1D Kirkpatrick-Baez module, 2D Kirkpatrick-Baez module, both developed within the EU Horizon 2020 AHEAD Project, as well as the Lobster{Eye module REX for the rocket flight experiment.

Outgassing monitor on VZLUSAT-1: Preliminary results

  • DOI: 10.1002/asna.201813507
  • Odkaz: https://doi.org/10.1002/asna.201813507
  • Pracoviště: Katedra fyziky, Katedra radioelektroniky
  • Anotace:
    The first current results of an outgassing monitor on board of the first Czech CubeSat launched into Earth's orbit are presented in this article. VZLUSAT-1 was launched in June 2017 as a technological satellite and is still operating in LEO orbit. A newly developed carbon fibre reinforced plastic, which can be used as a radiation shield, is one of the tested items on board. The amount of outgassing of is one of the critical properties for space applications. Water vapour is the largest part of matter outgassed from mounted composites and other components. Thus a novel monitoring device based on several types of humidity sensors was proposed to be used on board of the VZLUSAT--1 nanosatellite as one of the payloads. This paper presents the responses of these sensors and discussed their applicability in space environment.

Radiation resistance monitor on VZLUSAT‐1: Preliminary results

  • DOI: 10.1002/asna.201813510
  • Odkaz: https://doi.org/10.1002/asna.201813510
  • Pracoviště: Katedra fyziky, Katedra radioelektroniky
  • Anotace:
    The technological CubeSat VZLUSAT‐1 was launched in June 2017, and carries a number of scientific and commercial experiments aboard. Several of them are focused on in‐orbit investigation of a novel carbon‐fiber composite developed by the 5 M company; examination of residual liquid evaporation, change of eigenfrequencies of the material due to aging, and shielding abilities against cosmic radiation. The quality of shielding is evaluated from a comparative measurement between three channels with different shielding. Each channel contains a calibrated biased PIN (p‐type, intrinsic, n‐type semiconductor regions) diode as the radiation sensor, which is sensitive to radiation in the 6–80 keV energy range. Preliminary results from the in‐orbit measurements are presented in this paper.

Study of multiple layers coatings for X-ray mirrors

  • Pracoviště: Katedra fyziky, Katedra radioelektroniky
  • Anotace:
    This paper focuses on a theoretical background that motivated the experimental campaign of multiple layer coatings of X-ray mirrors, and the first results of the testing of the prepared samples. Simulations of the use of different overcoats were performed in order to improve the reflectivity of thin iridium coatings designed for X-ray optics effective in the energy up to 10 keV. Samples based on these simulations were prepared and are being tested for the properties that influence the X-ray optical performance, such as layer homogeneity, density and surface micro-roughness. Further the topic of the coating stress was addressed, as it is an issue in case of thin, lightweight X-ray mirrors and affects the time stability of layers. The discussion and preliminary results conclude our contribution.

VZLUSAT‐1: Health monitoring system, preliminary results

  • DOI: 10.1002/asna.201813513
  • Odkaz: https://doi.org/10.1002/asna.201813513
  • Pracoviště: Katedra fyziky, Katedra radioelektroniky
  • Anotace:
    The health monitoring (HM) system placed on VZLUSAT‐1 nondestructively measures the mechanical and thermal properties of the newly developed carbon fiber material for space usage. The carbon material is exposed to the vacuum, radiation, and temperature changes in space. It can be used as a substitute for the currently used aluminum alloys because it has lower mass density and better mechanical properties compared to aluminum. The HM payload evaluates the quality changes of a material according to the difference in Young's modulus. Young's modulus of elasticity is a characteristic property of every solid material, and on VZLUSAT‐1 it is measured in terms of the eigenfrequencies of a free‐hanging beam. In this paper we present the first data measured in orbit – the eigenfrequencies, attenuation, and six temperatures from a carbon fiber panel. Based on these data, the quality of the mechanical properties and time stability are determined over the VZLUSAT‐1's life span.

Zušlechťování mandrelů pro výroby RTG optik metodami vysokofrekvenčního odprašování a opracovávání iontovým svazkem

  • Pracoviště: Katedra fyziky, Katedra radioelektroniky
  • Anotace:
    Tento článek se zabývá možnostmi úpravy povrchu mandrelů pro výrobu rentgenové optiky metodou galvanické replikace. Při výrobě této optiky je zcela zásadním parametrem mikrodrsnost, určující kvalitu a efektivitu odrazu dopadajícího záření. Zabývali jsme se testováním a porovnáním dvou způsobů zušlechťování povrchu mandrelů. Byla použita technika čištění vysokofrekvenčním plasmatem a opracování iontovým svazkem. Kvalita výsledných povrchů byla vyhodnocována pomocí měření mikroskopie atomárních sil (AFM) a na RTG reflektometru.

Data processing from lobster eye type optics

  • DOI: 10.1117/12.2265724
  • Odkaz: https://doi.org/10.1117/12.2265724
  • Pracoviště: Katedra fyziky, Katedra radioelektroniky
  • Anotace:
    Wolter I optics are commonly used for imaging in X-Ray spectrum. This system uses two reflections, and at higher energies, this system is not so much efficient but has a very good optical resolution. Here is another type of optics Lobster Eye, which is using also two reflections for focusing rays in Schmidt's or Angel's arrangement. Here is also possible to use Lobster eye optics as two one dimensional independent optics. This paper describes advantages of one dimensional and two dimensional Lobster Eye optics in Schmidt's arrangement and its data processing - find out a number of sources in wide field of view. Two dimensional (2D) optics are suitable to detect the number of point X-ray sources and their magnitude, but it is necessary to expose for a long time because a 2D system has much lower transitivity, due to double reflection, compared to one dimensional (1D) optics. Not only for this reason, two 1D optics are better to use for lower magnitudes of sources. In this case, additional image processing is necessary to achieve a 2D image. This article describes of approach an image reconstruction and advantages of two 1D optics without significant losses of transitivity.

Detection of X-ray spectra and images by Timepix

  • Pracoviště: Katedra fyziky, Katedra radioelektroniky
  • Anotace:
    X-ray monitoring for astrophysical applications mainly consists of two parts - optics and detector. The article describes an approach based on a combination of Lobster Eye (LE) optics with Timepix detector. Timepix is a semiconductor detector with 256×256 pixels on one electrode and a second electrode is common. Usage of the back-side-pulse from an common electrode of pixelated detector brings the possibility of an additional spectroscopic or trigger signal. In this article are described effects of the thermal stabilisation, and the cooling effect of the detector working as single pixel.

Development of iridium coated silicon X-ray mirrors for Lobster Eye astronomical telescopes

  • Pracoviště: Katedra fyziky, Katedra radioelektroniky
  • Anotace:
    Development of iridium coated silicon X-ray mirrors for Lobster Eye astronomical telescopes Content X-ray optics. Current state and mission Used technologies Grazing incidence mirrors Hybrid optics Coating process and layers properties Conclusion Aknowledgements. X-ray optics Current orbital missions Chandra, XMM Newton Wolter I system VZLUSAT-1 Lobster eye imaging system. Hybrid optics Schmidt's and Kirkpatrick-Baez arrangement

Development of iridium coated x-ray mirrors for astronomical applications

  • Autoři: Döhring, T., Probst, A.-C., Emmerich, F., Stollenwerk, M., Ing. Veronika Stieglitz, Ph.D., Friedrich, P., Damm, Ch.
  • Publikace: Optics for EUV, X-Ray, and Gamma-Ray Astronomy VIII 2017. Bellingham WA: The International Society for Optical Engineering (SPIE), 2017. Proceedings of SPIE. vol. 10399. ISSN 0277-786X. ISBN 978-1-5106-1255-6.
  • Rok: 2017
  • DOI: 10.1117/12.2273988
  • Odkaz: https://doi.org/10.1117/12.2273988
  • Pracoviště: Katedra radioelektroniky
  • Anotace:
    Future space-based X-ray observatories need to be very lightweight for launcher mass constraints. Therefore they will use a reduced mirror thickness, which results in the additional requirement of low coating stress to avoid deformation of the initial precisely shaped mirror substrates. Due to their excellent reflection properties iridium coatings are sometimes applied for grazing incidence mirrors in astronomical X-ray telescopes. At Aschaffenburg University of Applied Sciences the coating of thin iridium films by an RF-magnetron sputtering technique is under development. The work is embedded in collaborations with the Max-Planck-Institute for Extraterrestrial Physics in Germany, the Czech Technical University in Prague, the Osservatorio Astronomico di Brera in Italy, the German Leibniz Institute for Solid State and Materials Research in Dresden, and the French Institute Fresnel. Sputtering with different parameters leads to iridium films with different properties. The current work is focused on the microstructure of the iridium coatings to study the influence of the substrate and of the argon gas pressure on the thin film growing process. Correlations between coating density, surface micro-roughness, the crystalline structure of the iridium layers, and the expected reflectivity of the X-ray mirror as well as coating stress effects are presented and discussed. The final goal of the project is to integrate the produced prototype mirrors into an X-ray telescope module. On a longer timescale measurements of the mirror modules optical performance are planned at the X-ray test facility PANTER

Hard X-ray Vela supernova observation on rocket experiment WRX-R

  • Pracoviště: Katedra fyziky, Katedra radioelektroniky
  • Anotace:
    This paper presents a hard X-ray telescope for the Vela nebula observation during a sounding rocket flight. The Water Recovery X-ray Rocket (WRX-R) experiment is organised by the Pennsylvania State University (PSU), USA with a primary payload of a soft X-ray spectroscope. The Czech team developed a hard X-ray Lobster-eye telescope as a secondary payload. The Czech experiment's astrophysical object of study is the Vela pulsar in the centre of the Vela nebula.

Indirect glass slumping of grazing incidence mirror segments for lightweight X-ray telescopes

  • Autoři: Ing. Veronika Stieglitz, Ph.D., Proserpio, L., Friedrich, P., Madarasz, E., Breunig, E., Burwitz, V., Dohring, T., Probst, A.C.
  • Publikace: Optics for EUV, X-Ray, and Gamma-Ray Astronomy VIII 2017. Bellingham WA: The International Society for Optical Engineering (SPIE), 2017. Proceedings of SPIE. vol. 10399. ISSN 0277-786X. ISBN 978-1-5106-1255-6.
  • Rok: 2017
  • DOI: 10.1117/12.2272671
  • Odkaz: https://doi.org/10.1117/12.2272671
  • Pracoviště: Katedra radioelektroniky
  • Anotace:
    The paper provides a description of recent progress in the development of lightweight, precision and high throughput grazing-incidence mirrors for X-ray astronomy made of glass. In particular, the indirect slumping technology under investigation at the Max Planck Institute for Extraterrestrial Physics (MPE) is reviewed and recent activities are presented together with the research approach. The glass slumping technique foresees several steps: a thermal forming process using a suitable mould; a reflective layer application; the alignment and integration of mirror segments into a supporting structure; and the final verification of prototype modules using X-rays. Each step is considered at MPE, with the involvement of partner institutes and universities. The last year of activities was mainly dedicated to the procurement of new moulds and to the application of Iridium coating. The main results will be presented.

JEUMICO – Bayerisch-tschechische Kooperation zur Entwicklung von Röntgenteleskopen

  • Pracoviště: Katedra radioelektroniky
  • Anotace:
    JEUMICO – Bayerisch-tschechische Kooperation zur Entwicklung von Röntgenteleskopen will be presented and discused

Lobster eye X-ray optics: Data processing from two 1D modules

  • Pracoviště: Katedra fyziky, Katedra radioelektroniky
  • Anotace:
    The X-ray imaging is usually done by Wolter I telescopes. They are suitable for imaging of a small part of the sky, not for all-sky monitoring. This monitoring could be done by a Lobster eye optics which can theoretically have a field of view up to 360deg. All sky monitoring system enables a quick identification of source and its direction. This paper describes the possibility of using two independent one-dimensional Lobster Eye modules for this purpose instead of Wolter I and their post-processing into an 2D image. This arrangement allows scanning with less energy loss compared to Wolter I or two-dimensional Lobster Eye optics. It is most suitable especially for very weak sources.

Optimization of microroughness of replicated X-ray optics

  • DOI: 10.1117/12.2265810
  • Odkaz: https://doi.org/10.1117/12.2265810
  • Pracoviště: Katedra fyziky, Katedra radioelektroniky
  • Anotace:
    We report on our work of minimizing the microroughness of replicated grazing incidence X-ray optics. Ion beam and RF sputter cleaning was used as surface treatment and we compare its effects in the article. Vacuum deposition of smoothing layers was also used for minimizing the microroughness. The surfaces were measured by atomic force microscopy and X-ray reflectometry. Microroughness less than 0,5 nm RMS and Ra was achieved.

Prototyping iridium coated mirrors for x-ray astronomy

  • Autoři: Döhring, T., Probst, A.-C., Stollenwerk, M., Emmerich, F., Ing. Veronika Stieglitz, Ph.D., Inneman, A.
  • Publikace: Proc. SPIE 10235, EUV and X-ray Optics: Synergy between Laboratory and Space V. Bellingham WA: The International Society for Optical Engineering (SPIE), 2017. Proceedings of SPIE. vol. 10235. ISSN 1996-756X. ISBN 978-1-5106-0971-6.
  • Rok: 2017
  • DOI: 10.1117/12.2265931
  • Odkaz: https://doi.org/10.1117/12.2265931
  • Pracoviště: Katedra radioelektroniky
  • Anotace:
    X-ray astronomy uses space-based telescopes to overcome the disturbing absorption of the Earth´s atmosphere. The telescope mirrors are operating at grazing incidence angles and are coated with thin metal films of high-Z materials to get sufficient reflectivity for the high-energy radiation to be observed. In addition the optical payload needs to be light-weighted for launcher mass constrains. Within the project JEUMICO, an acronym for “Joint European Mirror Competence”, the Aschaffenburg University of Applied Sciences and the Czech Technical University in Prague started a collaboration to develop mirrors for X-ray telescopes. The X-ray telescopes currently developed within this Bavarian- Czech project are of Lobster eye type optical design. Corresponding mirror segments use substrates of flat silicon wafers which are coated with thin iridium films, as this material is promising high reflectivity in the X-ray range of interest. The deposition of the iridium films is based on a magnetron sputtering process. Sputtering with different parameters, especially by variation of the argon gas pressure, leads to iridium films with different properties. In addition to investigations of the uncoated mirror substrates the achieved surface roughness has been studied. Occasional delamination of the iridium films due to high stress levels is prevented by chromium sublayers. Thereby the sputtering parameters are optimized in the context of the expected reflectivity of the coated X-ray mirrors. In near future measurements of the assembled mirror modules optical performances are planned at an X-ray test facility.

Radiometric calibration of wide-field camera system with an application in astronomy

  • DOI: 10.1117/12.2274719
  • Odkaz: https://doi.org/10.1117/12.2274719
  • Pracoviště: Katedra radioelektroniky
  • Anotace:
    Camera response function (CRF) is widely used for the description of the relationship between scene radiance and image brightness. Most common application of CRF is High Dynamic Range (HDR) reconstruction of the radiance maps of imaged scenes from a set of frames with different exposures. The main goal of this work is to provide an overview of CRF estimation algorithms and compare their outputs with results obtained under laboratory conditions. These algorithms, typically designed for multimedia content, are unfortunately quite useless with astronomical image data, mostly due to their nature (blur, noise, and long exposures). Therefore, we propose an optimization of selected methods to use in an astronomical imaging application. Results are experimentally verified on the wide-field camera system using Digital Single Lens Reflex (DSLR) camera.

Study of lobster eye optics with iridium coated X-ray mirrors for a rocket experiment

  • DOI: 10.1117/12.2265769
  • Odkaz: https://doi.org/10.1117/12.2265769
  • Pracoviště: Katedra radioelektroniky
  • Anotace:
    In the field of astronomical X-ray telescopes, different types of optics based on grazing incidence mirrors can be used. This contribution describes the special design of a lobster-eye optics in Schmidt's arrangement, which uses dual reflection to increase the collecting area. The individual mirrors of this wide-field telescope are made of at silicon wafers coated with reflecting iridium layers. This iridium coatings have some advantages compared to more common gold layers as is shown in corresponding simulations. The iridium coating process for the X-ray mirrors was developed within a cooperation of the Aschaffenburg University of Applied Sciences and the Czech Technical University in Prague. Different mirror parameters essential for a proper function of the X-ray optics, like the surface microroughness and the problematic of a good adhesion quality of the coatings were studied. After integration of the individual mirrors into the final lobster-eye optics and the corresponding space qualification testing it is planned to fly the telescope in a recently proposed NASA rocket experiment.

Uncooled spectrometer for X-ray astrophysics

  • DOI: 10.1117/12.2265744
  • Odkaz: https://doi.org/10.1117/12.2265744
  • Pracoviště: Katedra fyziky, Katedra radioelektroniky
  • Anotace:
    In the field of X-ray detection for Astrophysics there are mainly two objectives; first is to create 2D images as a result of sensing radiation by detectors consisting of a pixels matrix and the second is a spectral analysis of the incident radiation. For spectral analysis, the basis is usually the principle of diffraction. This paper describes the new design of X-ray spectrometer based on Timepix detector with optics positioned in front of it. The advantage of this setup is the ability to get the image and spectrum from the same devices. With other modifications is possible to shift detection threshold into areas of soft X-ray radiation.

VZLUSAT-1: Nanosatellite with miniature lobster eye X-ray telescope and qualification of the radiation shielding composite for space application

  • DOI: 10.1016/j.actaastro.2017.08.004
  • Odkaz: https://doi.org/10.1016/j.actaastro.2017.08.004
  • Pracoviště: Katedra radioelektroniky, Multirobotické systémy
  • Anotace:
    In the upcoming generation of small satellites there is a great potential for testing new sensors, processes and technologies for space and also for the creation of large in situ sensor networks. It plays a significant role in the more detailed examination, modelling and evaluation of the orbital environment. Scientific payloads based on the CubeSat technology are also feasible and the miniature X-ray telescope described in this paper may serve as an example. One of these small satellites from CubeSat family is a Czech CubeSat VZLUSAT-1, which is going to be launched during QB50 mission in 2017. This satellite has dimensions of 100 mm × 100 mm × 230 mm. The VZLUSAT-1 has three main payloads. The tested Radiation Hardened Composites Housing (RHCH) has ambitions to be used as a structural and shielding material to protect electronic devices in space or for constructions of future manned and unmanned spacecraft as well as Moon or Martian habitats. The novel miniaturized X-ray telescope with a Lobster Eye (LE) optics represents an example of CubeSat’s scientific payload. The telescope has a wide field of view and such systems may be essential in detecting the X-ray sources of various physical origin. VZLUSAT-1 also carries the FIPEX payload which measures the molecular and atomic oxygen density among part of the satellite group in QB50 mission. The VZLUSAT-1 is one of the constellation in the QB50 mission that create a measuring network around the Earth and provide multipoint, in-situ measurements of the atmosphere. This paper presents the VZLUSAT-1 satellite including the details about subsystems and payloads. The spacecraft was built between 2011 and 2015. In 2017, our VZLUSAT-1 team has finished the testing phase on a protoflight model and the VZLUSAT-1 is ready to be launched on a circular polar orbit at altitude 500 km ± 20 km.

X-ray Lobster Eye all-sky monitor for rocket experiment

  • DOI: 10.1117/12.2277515
  • Odkaz: https://doi.org/10.1117/12.2277515
  • Pracoviště: Katedra radioelektroniky, Multirobotické systémy
  • Anotace:
    This paper presents a Lobster Eye (LE) X-ray telescope developed for the Water Recovery X-ray Rocket (WRX-R) experiment. The primary payload of the rocket experiment is a soft X-ray spectroscope developed by the Pennsylvania State University (PSU), USA. The Czech team participates by hard LE X-ray telescope as a secondary payload. The astrophysical objective of the rocket experiment is the Vela Supernova of size about 8deg × 8deg. In the center of the nebula is a neutron star with a strong magnetic field, roughly the mass of the Sun and a diameter of about 20 kilometers forming the Vela pulsar. The primary objective of WRX-R is the spectral measurement of the outer part of the nebula in soft X-ray and FOV of 3.25deg × 3.25deg. The secondary objective (hard LE X-ray telescope) is the Vela neutron star observation. The hard LE telescope consists of two X-ray telescopes with the Timepix detector. First telescope uses 2D LE Schmidt optics (2D-LE-REX) with focal length over 1m and 4 Timepix detectors (2 × 2 matrix). The telescope FOV is 1.5deg × 1.5deg with spectral range from 3keV to 60keV. The second telescope uses 1D LE Schmidt optics (1D-LE-REX) with focal length of 25cm and one Timepix detector. The telescope is made as a wide field with FOV 4.5deg × 3.5deg and spectral range from 3keV to 40keV. The rocket experiment serves as a technology demonstration mission for the payloads. The LE X-ray telescopes can be in the future used as all‐sky monitor/surveyor. The astrophysical observation can cover the hard X-ray observation of astrophysical sources in time-domain, the GRBs surveying or the exploration of the gravitational wave sources.

Image processing from X-Ray 1D and 2D Lobster eye optics

Miniaturized X-ray telescope for VZLUSAT-1 nanosatellite with Timepix detector

  • DOI: 10.1088/1748-0221/11/10/C10007
  • Odkaz: https://doi.org/10.1088/1748-0221/11/10/C10007
  • Pracoviště: Katedra kybernetiky, Katedra radioelektroniky
  • Anotace:
    We present the application of a Timepix detector on the VZLUSAT-1 nanosatellite. Timepix is a compact pixel detector (256×256 square pixels, 55×55 μm each) sensitive to hard X-ray radiation. It is suitable for detecting extraterrestrial X-rays due to its low noise characteristics, which enables measuring without special cooling. This project aims to verify the practicality of the detector in conjunction with 1-D Lobster-Eye optics to observe celestial sources between 5 and 20 keV. A modified USB interface (developed by IEAP at CTU in Prague) is used for low-level control of the Timepix. An additional 8-bit Atmel microcontroller is dedicated for commanding the detector and to process the data onboard the satellite. We present software methods for onboard post-processing of captured images, which are suitable for implementation under the constraints of the low-powered embedded hardware. Several measuring modes are prepared for different scenarios including single picture exposure, solar UV-light triggered exposure, and long-term all-sky monitoring. The work has been done within Medipix2 collaboration. The satellite is planned for launch in April 2017 as a part of the QB50 project with an end of life expectancy in 2019.

New possibilities in the detection of X-ray spectra and images

Rating of authors

  • Pracoviště: Katedra radioelektroniky
  • Anotace:
    There is a vast theoretical background for evaluation of scientific works and there are a lot of ways how to, if possible, objectively evaluate the significance and quality of individual theses, authors and researches. Various evaluation elements are more or less objective in different branches of research and it is necessary to consider suitability of their use and "justness" of the final comparison. Then it depends on each metric, how it uses these and other parameters and how many iterations it logs. Elementary ways of calculation of these indicators of quality, their properties and scientific power evaluation of an researcher are briefly explained in this article.

Reflective coating layers for X-ray optics

Terrestrial gamma-ray flashes monitor demonstrator on CubeSat

  • DOI: 10.1117/12.2240299
  • Odkaz: https://doi.org/10.1117/12.2240299
  • Pracoviště: Katedra kybernetiky, Katedra radioelektroniky
  • Anotace:
    The CubeSat mission with the demonstrator of miniaturized X-ray telescope is presented. The paper presents one of the mission objectives of using the instrument for remote sensing of the Terrestrial Gamma-ray Flashes (TGFs). TGFs are intense sources of gamma-rays associated with lightning bolt activity and tropical thunderstorms. The measurement of TGFs exists and was measured by sounding rockets, high altitude balloons or several satellite missions. Past satellite missions were equipped with different detectors working from 10 keV up to 10 MeV. The RHESSI mission spectrum measurement of TGFs shows the maximum counts per second around 75 keV. The used detectors were in general big in volume and cannot be utilized by the CubeSat mission. The presented CubeSat is equipped with miniaturized X-ray telescope using the Timepix non-cooled pixel detector. The detector works between 3 and 60 keV in counting mode (dosimetry) or in spectrum mode with resolution 5 keV. The wide-field X-ray »Lobster-eye» optics/collimator (depending on energy) is used with a view angle of 3 degrees for the source location definition. The UV detectors with FOV 30 degrees and 1.5 degrees are added parallel with the optic as a part of the telescope. The telescope is equipped with software distinguishing between the photons and other particles. Using this software the TGF's detection is possible also in the field of South Atlantic anomaly. For the total ionization dose, the additional detector is used based on Silicone (12-60 keV) and CdTe (20 keV - 1 MeV). The presented instruments are the demonstrators suitable also for the astrophysical, sun and moon observation. The paper shows the details of TGF's observation modes, detectors details, data processing and handling system and mission. The CubeSat launch is planned to summer 2016. © Copyright SPIE. Downloading of the abstract is permitted for personal use only.

Use of ion beam and RF sputter cleaning as a surface treatment for X-Ray optics

  • Pracoviště: Katedra fyziky, Katedra radioelektroniky
  • Anotace:
    We compare the methods of ion beam etching/milling and RF sputter cleaning with regard to their application in production of grazing incidence X-ray optics. We studied its effects on smooth surfaces and its potential for achieving low microroughness. The sample surfaces were measured by atomic force microscopy and X- ray reflectometry.

VZLUSAT-1: verification of new materials and technologies for space

  • DOI: 10.1117/12.2244035
  • Odkaz: https://doi.org/10.1117/12.2244035
  • Pracoviště: Katedra radioelektroniky
  • Anotace:
    CubeSats are a good opportunity to test new technologies and materials on orbit. These innovations can be later used for improving of properties and life length of Cubesat or other satellites as well. VZLUSAT-1 is a small satellite from the CubeSat family, which will carry a wide scale of payloads with different purposes. The poster is focused on measuring of degradation and properties measurement of new radiation hardened composite material in orbit due to space environment. Material properties changes can be studied by many methods and in many disciplines. One payload measures mechanical changes in dependence on Young's modulus of elasticity which is got from non-destructive testing by mechanical vibrations. The natural frequencies we get using Fast Fourier Transform. The material is tested also by several thermometers which measure heat distribution through the composite, as well as reflectivity in dependence on different coatings. The satellite also will measure the material radiation shielding properties. There are PIN diodes which measure the relative shielding efficiency of composite and how it will change in time in space environment. Last one of material space testing is measurement of outgassing from tested composite material. It could be very dangerous for other parts of satellite, like detectors, when anything was outgassing, for example water steam. There are several humidity sensors which are sensitive to steam and other gases and measures temperatures as well.

Space measurement on VZLUSAT-1 - Evaporation of CFRE material

  • Pracoviště: Katedra fyziky, Katedra radioelektroniky
  • Anotace:
    This poster talks about evaporation measurement on orbit. This payload is placed onboard of Nanosatellite VZLUSat-1. There are described humidity sensors and results of their calibration for space environment.

Space measurement on VZLUSAT-1 - Mechanical properties of CFRE

  • Pracoviště: Katedra fyziky, Katedra radioelektroniky
  • Anotace:
    This poster talks about measurement of Carbon fibre material, which is tested on orbit on nanosatellite VZLUSAT-1. There are described process of measurements and their results.

Space measurement on VZLUSAT-1 - Radiaton endurance of CFRE

  • Pracoviště: Katedra fyziky, Katedra radioelektroniky
  • Anotace:
    This poster talks about measurement of radiation shielding. Quality of shielding is important for longterm application on orbit.

Measuring carbon fiber aging on orbit

  • Pracoviště: Katedra fyziky, Katedra mikroelektroniky
  • Anotace:
    This paper describes the outcome of internship at the faculty of science and engineering, Hosei University in summer 2014. The goal of the project is to design a measuring system of aging properties of a carbon fiber reinforced composite in space. The project is a part of the nano-satellite project at Czech Technical University in Prague, scheduled to be launched in 2016. The measurement environment In space is different from the standard measurements performed on the ground in laboratory. The system design specification has a large constraint in size, weight and power consumption by the limit of space probes. To meet these requirement, the basic measuring system of the mechanical damping characteristics of the carbon fiber composite is designed in this internship project. A damping oscillator to simulate the response of the target material has been assembled and measuring parameters arc optimized. The optimized algorithm has been implemented in the chip to be launched on the space orbit.

Za stránku zodpovídá: Ing. Mgr. Radovan Suk