Lidé

Ing. Martin Urban

Všechny publikace

REX: X-ray experiment on the water recovery rocket

  • DOI: 10.1016/j.actaastro.2021.03.019
  • Odkaz: https://doi.org/10.1016/j.actaastro.2021.03.019
  • Pracoviště: Katedra fyziky, Katedra radioelektroniky, Multirobotické systémy
  • Anotace:
    This paper presents Rocket Experiment (REX) that was part of a dual-payload rocket campaign for NASA’s sounding rocket Black Brant IX with water recovery technology. This mission was a suborbital sounding rocket flight that was launched and recovered on April 4, 2018 and targeted the Vela supernova remnant. The purpose of REX was to classify the Technology Readiness Level of onboard devices designed for space applications. The devices were two wide-field X-ray telescopes consisting of a combination of Lobster-Eye (LE) optics with an uncooled Timepix detector (256 px × 256 px @ 55 μm), and additional sensors. The first telescope uses a two-dimensional combination of LE modules with a focal length of 1 m and a Field of View (FOV) of 1.0◦ × 1.2◦ and operates in the energy range of 3 – 60 keV. The second telescope was a one-dimensional LE with a focal length of 243 mm and a FOV of 2.7◦ × 8.0◦ for the energy range 3 – 40 keV. The X-ray telescopes were supplemented by a camera in the visible spectrum with 1.280 px × 1.024 px resolution, which was used to obtain images of the observed sources and to verify the resulting pointing of the rocket carrier. Other devices also include infrared array sensors and inertial measurement units tested for future small satellite missions. The data handler and communication system were built using the Robot Operating System, and both the system and the electronics were deployed and operated in-flight. The hardware was successfully recovered after the launch and the data were extracted

Timepix3: Temperature influence on X-ray measurements in counting mode with Si sensor  

  • Autoři: Ing. Martin Urban, Doubravová, D.
  • Publikace: Radiation Measurements. 2021, 141 ISSN 1350-4487.
  • Rok: 2021
  • DOI: 10.1016/j.radmeas.2021.106535
  • Odkaz: https://doi.org/10.1016/j.radmeas.2021.106535
  • Pracoviště: Katedra radioelektroniky
  • Anotace:
    The Timepix3 radiation imaging and particle tracking detector is the direct successor to the Timepix semiconductor detector developed in CERN. The Timepix ASIC chip (256×256 pixels with a pitch of 55 µm provides the possibility to operate each of the 65 536 pixels in one of the following modes: (1) event counting (Medipix mode); (2) energy measurement (Time over Threshold - ToT mode); and (3) measurement of the interaction time (Time of Arrival - ToA mode). The Timepix3 chip of the new generation introduces the ability to measure ToT and ToA simultaneously and also the event-based readout where each hit pixel is read out immediately after the hit. This detector can be used in a variety fields of science including particle physics, X-ray imaging as well as medicine and space science. With regards to the wide application possibilities of this detector, we investigate the properties of the detector in the temperature range from -20 ◦C to +80 ◦C. This temperature range spans the majority of laboratory conditions as well as requirements for most of outer space missions. This paper describes thermal-vacuum testing of the most common 300 µm Si detector with AdvaPIX readout interface in the counting mode. The detector was stabilized under various thermal conditions in a thermal vacuum chamber and subsequently exposed to characteristic X-ray radiation of 5 elements in the energy range of 4{24 keV. It was found that the absolute measurement accuracy of higher energies is more affected by higher temperature (up to 0.8 keV @ 17.48 keV) and relative error of Timepix3 accuracy is inversely proportional to the incident X-ray energy. The relative precision is kept in the range of 6% for temperatures from -20 ◦C to +60 ◦C with significant change at +80 ◦C.

Thermal vacuum testing of Timepix3 detector

  • DOI: 10.1088/1748-0221/15/03/C03040
  • Odkaz: https://doi.org/10.1088/1748-0221/15/03/C03040
  • Pracoviště: Katedra radioelektroniky
  • Anotace:
    The thermal dependence of semiconductor detectors is one of their critical properties. This paper presents the results of the Timepix3 detector thermal vacuum testing, with respect to the effects on its properties and sensitivity. The Timepix3 represents a new generation of Timepix chips of the Medipix family, and it is equipped with an event-based mode of detection allowing for simultaneous measurement of the position, time and energy of an incident particle. Due to their properties, Timepix3 detectors are very suitable for space applications. Given that this is a relatively new device, the influence of temperature is not described in detail yet, especially for space usage. The operation of the device in a broad range of temperatures is required (e.q. QB50 mission on LEO from -20 °C to +50 °C). Timepix detectors have been used already in space missions, e.g. VZLUSAT-1, LUCID and SATRAM missions. In space, thermal cycling of the detectors occurs and this results in measurement distortion because both the noise edge and energy spectra are affected by changes in temperature. The experiments were performed on a detector equipped with a 300 µm thick Si sensor. The detector was equalised under various thermal conditions in vacuum and subsequently exposed to several energies of X-ray radiation corresponding to the characteristic radiation of 5 elements in the energy range of 4 - 24 keV. The results of these tests improve the knowledge regarding the behaviour of the essential components of the detector under extreme conditions. This new information can be used to improve measurements and thus minimise external influences, for example, in space applications but also in other fields where temperature stabilisation of the detector is very difficult or energy-consuming.

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.

Lobster eye optics: Position determination based on 1D optics with simple code mask

  • DOI: 10.1117/12.2528505
  • Odkaz: https://doi.org/10.1117/12.2528505
  • Pracoviště: Katedra fyziky, Katedra radioelektroniky
  • Anotace:
    Lobster eye X-ray optics in the one dimensional (1D) arrangement has advantages in higher reflectivity, especially for higher energies, compared to classical two dimensional (2D) Schmidt’s arrangement. One dimensional optics can determine only one direction of the incoming beam. There is placed a strip in front of the optics for determining of the second direction. This strip is made of X-ray proof material which blocks the incoming beam and thus causes a gap in the line. Based on these facts, it is possible to determine the position of each point source which has enough signal to gap ratio. Unfortunately, the intensity of sources is not possible to assess by this method.

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.

Satellite temperature measurement in LEO and improvement method of temperature sensors calibration based on measured data

  • DOI: 10.1002/asna.201913671
  • Odkaz: https://doi.org/10.1002/asna.201913671
  • Pracoviště: Katedra fyziky, Katedra radioelektroniky
  • Anotace:
    This article describes the temperature measurement and its calibration on board of the nanosatellite CubeSat class VZLUSAT-1. There are several thermometers, installed with an analogue and a digital output, which are necessary for the accurate measurements calibrations under a vacuum condition or for applying post-processing corrections. This document describes the way of calibration in a thermal vacuum chamber and its improvement in orbit. In addition, the paper will discusses the use of a RTD platinum sensors Pt1000 and a digital sensors HYT271 as the reference. A correction variable based on HYT271 compensates a nonlinearity of Pt1000 as well as minimise the influence of change in a measuring current due to temperature changes. The current correction variable is a function of temperature and nanosatellite’s position in the orbit. The measured temperatures are below -70 ◦C in the Earth’s shadow and greater than +80 ◦C after irradiation by the Sun. Orbital temperature calibration is performed in two steps. The raw temperatures data obtained during the orbital measurement are being used for further improvement. The measurement cycle consists of the electronics calibration, temperature measurement and temperature calibration. After applying the temperature correction process, the final accuracy is better than, 0.15 ◦C

Timepix: Influence of temperature and vacuum on equalisation of X-ray detector and its verification

  • DOI: 10.1117/12.2528503
  • Odkaz: https://doi.org/10.1117/12.2528503
  • Pracoviště: Katedra fyziky, Katedra radioelektroniky
  • Anotace:
    The thermal dependence of the semiconductor detector is one of the critical properties. This manuscript describes changes in the threshold scans, equalisation and its verification for the particle counting pixel detector Timepix. The Timepix detector family has great potential for use not only in space, i.e. for small satellite (CubeSat) missions, but also in many other areas like medicine, material testing or particle colliders (i.e. Large Hadron Collider). In this case, several experiments were performed with the Timepix detector under the vacuum conditions as well as ambient conditions with the thermal stabilisation at several temperatures in a range from -15 ◦C to +80 ◦C. This paper describes the early experimental results of the chip temperature dependence. The detector equalisation and validity of the original equalisation dependently on different temperatures is examined. The changes in the detector could cause the errors and shifts of the detection limit for low-energies.

Kirkpatrick Baez X-ray optics for astrophysics: Recent status

  • Pracoviště: Katedra radioelektroniky
  • Anotace:
    X-ray optics in Kirkpatrick Baez arrangement represent promising alternative to Wolter optics in common use. We present briefly recent status of design, developments, and tests of this kind of X–ray optics including Kirkpatrick Baez module developed and tested within the EU AHEAD project.

Lobster Eye X-ray optics for astrophysics: Recent status

  • Pracoviště: Katedra radioelektroniky
  • Anotace:
    X-ray optics in Lobster Eye arrangement represent promising complementary device to narrow field X-ray optics in common use. We present briefly recent status of design, developments, and tests of X-ray optics including Lobster Eye modules developed and tested within recent space project.

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

  • Autoři: Pína, L., prof. RNDr. René Hudec, CSc., Inneman, A., Ing. Ondřej Nentvich, Ing. Martin Urban, Maršíková, V., Stehlíková, V., Doubravová, D., Burwitz, V., Pelliciari, C., Hartner, G., Dániel, V.
  • Publikace: Contributions of the Astronomical Observatory Skalnaté Pleso. 2018, 48(3), 466-475. ISSN 1335-1842.
  • Rok: 2018
  • 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.

Timepix in LEO Orbit onboard the VZLUSAT-1 Nanosatellite: 1-year of Space Radiation Dosimetry Measurements

  • DOI: 10.1088/1748-0221/13/11/C11010
  • Odkaz: https://doi.org/10.1088/1748-0221/13/11/C11010
  • Pracoviště: Katedra radioelektroniky, Multirobotické systémy
  • Anotace:
    The VZLUSAT-1 satellite, the first Czech CubeSat, was successfully launched on June 23, 2017, to a 510 km Sun-synchronous low-Earth orbit. It carries several scientific payloads including a Timepix detector as focal plane imager for the X-Ray telescope onboard. The Timepix detector contributes significantly to the satellite data collection, with more than 25 000 sampling acquisitions in the first year of deployment. Despite limitations of the satellite attitude control system, necessary for capturing X-Ray images of the Sun, the Timepix detector allows measuring the space radiation environment along the satellite orbit. As of September 2018, we conducted 33 whole-Earth mappings, recording radiation doses around the planet. Further, we show data from scans of the South Atlantic Anomaly and polar radiation horns, where the location and acquisition time were tailored to minimize event pile-up and particle track overlap. Since October 2017, the optics segment of the onboard X-Ray telescope was deployed, which exposed the Timepix detector unshielded to free open space. This change produced entirely new observations namely of low energy charged particles and a significant increase of measured particle flux. We also registered the effects of exposing the sensor to direct intense sunlight. We will summarize on the actual performance of the custom readout interface, which exceeds expectations in the constrained environment of the low-cost and low-powered CubeSat nanosatellite.

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

  • Autoři: Stehlíková, V., Probst, A., Ing. Ondřej Nentvich, Ing. Martin Urban, Inneman, A., Ing. Ladislav Sieger, CSc., Maršíková, V., Thorsten, D.
  • Publikace: Proceeding of 5th EOS Conference on Manufacturing of Optical Systems, Munich. München: Bayerische Akademie Munchen, 2017. ISBN 978-952-68553-3-2.
  • Rok: 2017
  • 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

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.

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

  • Autoři: Mikuličková, L., Pína, L., Inneman, A., Doubravová, D., Maršíková, V., Ing. Ladislav Sieger, CSc., Ing. Martin Urban, Stehlíková, V., Ing. Ondřej Nentvich, Mirovsky, J.
  • 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 0277-786X. ISBN 978-1-5106-0972-3.
  • Rok: 2017
  • 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.

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

  • Autoři: Stehlíková, V., Ing. Martin Urban, Ing. Ondřej Nentvich, Inneman, A., Döhring, T., Probst, A-C
  • 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 0277-786X. ISBN 978-1-5106-0972-3.
  • Rok: 2017
  • 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

  • Autoři: Ing. Martin Urban, Ing. Ondřej Nentvich, Stehlíková, V., Ing. Ladislav Sieger, CSc.,
  • 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 0277-786X. ISBN 978-1-5106-0972-3.
  • Rok: 2017
  • 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

  • Autoři: Dániel, V., Inneman, A., Pína, L., Zadražil, V., Ing. Tomáš Báča, Ph.D., Stehlíková, V., Ing. Ondřej Nentvich, Ing. Martin Urban, Maršíková, V., McEntaffer, R., Tutt, J., Schulz, T.
  • 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 0277-786X. ISBN 978-1-5106-0972-3.
  • Rok: 2017
  • 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

  • Autoři: Ing. Martin Urban, Ing. Ondřej Nentvich, Stehlíková, V., Inneman, A.
  • Publikace: 9th international workshop on astronomical X-Ray optics. Praha: ČVUT FEL, Katedra radioelektroniky, 2016.
  • Rok: 2016

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

  • Autoři: Stehlíková, V., Probst, A.-C., Ing. Ondřej Nentvich, Ing. Martin Urban,
  • Publikace: 9th international workshop on astronomical X-Ray optics. Praha: ČVUT FEL, Katedra radioelektroniky, 2016.
  • Rok: 2016

Terrestrial gamma-ray flashes monitor demonstrator on CubeSat

  • Autoři: Dániel, V., Pína, L., Inneman, A., Zadražil, V., Ing. Tomáš Báča, Ph.D., Platkevič, M., Stehlíková, V., Ing. Ondřej Nentvich, Ing. Martin Urban,
  • Publikace: CubeSats and NanoSats for Remote Sensing. Bellingham WA: The International Society for Optical Engineering (SPIE), 2016. ISSN 0277-786X. ISBN 9781510603479.
  • Rok: 2016
  • 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

  • Autoři: Dániel, V., Ing. Martin Urban, Ing. Ondřej Nentvich, Stehlíková, V.
  • Publikace: CubeSats and NanoSats for Remote Sensing. Bellingham WA: The International Society for Optical Engineering (SPIE), 2016. ISSN 0277-786X. ISBN 9781510603479.
  • Rok: 2016
  • 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