We briefly present selected results in the field of X-ray optics obtained within the project at the CTU in Prague in collaboration with other Czech Institutes, mainly Rigaku Prague, where X-ray optics modules were assembled. These efforts covered the simulations and designs of LE (Lobster Eye) and KB (Kirkpatrick-Baez) optical Systems, a study of new and alternative simulation/ray tracing methods, studies of alternative/improved coatings, studies of improved substrates (Si and float glass), design and assembly of new test modules where both LE and KB test modules were based on Multi Foil Technology (glass and Si substrates < 1mm) finished by tests in visible light and X-rays.

We present a Lobster Eye (LE) X-ray optics module utilizing Multi-Foil Optics (MFO) technology. Designed for CubeSat-class missions, the system is based on the Schmidt arrangement and consists of two orthogonally oriented submodules composed of smooth, gold-coated glass foils. This configuration enables wide-field X-ray imaging with a short focal length of 400 mm and a characteristic cross-shaped focal spot. Key optical parameters, including focal length, full width at half maximum (FWHM), angular resolution, field of view (FOV), and effective area, have been experimentally verified in a vacuum setup using various X-ray sources and detectors. The Lobster Eye (LE) X-ray optics is ready for integration into a CubeSat demonstrator.

Grazing incident Soft X-ray source (SXR) mirrors find applications in astrophysics, space plasma research, hot plasma research and in various imaging and spectroscopy laboratory systems. SXR sources and vacuum optical beamlines are needed for their characterization and testing. A micro focus laboratory Soft X-ray source, which can be used in facilities for SXR optical components metrology, was designed and realized. The source in vacuum consists of an electron gun with stabilized electron beam focused to a 200 um spot on a target from appropriate material. Four different targets allowing generation of SXR with four different energies from four different elements are placed on a rotational turret. Required photon energy can be selected without vacuum interruption.

We present very preliminary results the design, assembly, and tests of new Lobster Eye (LE) and Kirkpatrick Baez (KB) modules based on Multi Foil Optics technology (MFO). The LE X-ray optics is a wide field of view (FOV) optics type Lobster Eye (LE) with a short (400 mm) focal length (suitable for CubeSat application) based on Schmidt design. The 2D LE optics consists of two orthogonal sub-modules of flat smooth reflective foils and each sub-modules focuses in one direction. The key parameters (the FWHM, the FOV (Field of view), and angular resolution, effective area) of the 2D LE optic were measured with different detectors. The advantage of MFO LE is that for off-axis points the angular resolution is preserved throughout the FOV, as demonstrated by measuring. There is a combined detector system that includes two detectors - Timepix3 Quad and spectroscope. The benefit of the combined detector system was demonstrated in the real measurement. Moreover, a new generation multiple arrays module of 2D X-ray KB optics with long f (nearly 6 meters) based on multi-foil silicon assembling technology was designed, manufactured, and tested in optical light and in X-rays at the Panter facility and the preliminary results will be also presented and discussed.

We present a miniaturized and wide field-of-view X-ray and Gamma-ray imager consisting of a segmented 2D optics-collimator coupled to the high-sensitivity semiconductor pixel detector Timepix equipped with a high-Z sensor (CdTe 2000 μm thick). The compact payload has been deployed in low-Earth orbit (LEO) onboard the 3U Cubesat VZLUSAT-2 which was launched on 13 January 2022. The instrument is designed to verify small spacecraft borne observation in open space of hard X-ray and Gamma-ray sources both of celestial and atmospheric origin. High-resolution spectral-sensitive X-ray and Gamma-ray images are provided with enhanced event discrimination and wide field-of-view up to 60°. Description of the instrument together with response evaluation and tests in ground with well-defined sources are presented. The intended observational plan for in-orbit measurements is outlined along with astrophysical goals and issues.

This paper presents microsatellite spacecraft payload study for prompt observation of transient astrophysical objects in X-ray energy range. By combining telescope concepts and miniaturized detectors, the small spacecraft will be able to probe the X-ray temporal emissions of bright events such as Gamma-Ray Bursts (GRBs), X-ray transients or the electromagnetic counterparts of Gravitational Wave Events (GWEs), but also short and long term observations of other types of variable X-ray sources. The spacecraft is based on the CubeSat nanosatellite platform with a volume of 16U. The spacecraft carries two types of X-ray telescopes onboard. The first is intended for X-ray transient monitoring and localization, and the second for detailed spectroscopic observation. The X-ray monitor/localization telescope with wide field of view of several arc degrees is used for localization and flux measurement of X-ray transients, as well as for permanent monitoring of Galactic center area. This telescope is based on Lobster Eye X-ray optics together with pixel detector based on the Timepix3 Quad detector. Rapid follow-up observation by soft X-ray spectroscopy is enabled by a second X-ray spectroscopic telescope with limited FOV (Field of View) of several arcmins with no spatial and/or angular resolution. The spectroscopic telescope uses condenser optics based on replicated parabolic total reflection system (or, alternatively, Wolter system) and a Ketek X-ray SDD detector with energy resolution of about 130 eV as a detector. In addition to technical and instrumental aspects, observational strategy and astrophysical issues and justifications are also addressed in the paper.

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 x 256 px @ 55 mu m), 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 degrees x 1.2 degrees 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 degrees x 8.0 degrees for the energy range 3 -40 keV. The X-ray telescopes were supplemented by a camera in the visible spectrum with 1.280 px x 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.

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.

This paper presents the 2nd generation of the optical system for Rocket Experiment (REX2). This optical device is based on successful mission REX1. The purpose of REX2 is to verify X-ray optical system consisting of wide- field 2D X-ray Lobster-Eye (LE) optics with an uncooled Quad Timepix3 detector (512x512 px @ 55 um and spectrometer (active area 7 mm2, 145 eV @ 5.9 keV ). The 2D X-ray Lobster-Eye (LE) optics is a combination of two one-dimension LE modules with a focal length of up to 1 m and a FOV better than 4.0 x 4.0 deg. The proposed optical system has imaging capabilities (2.5 to 30 keV) and spectroscopy capabilities (0.2 to 10 keV). The optical system was recently tested in the X-ray vacuum chamber. The preliminary test results are presented and discussed in this paper.

The 2nd generation of the X-ray Multi-Foil Optical (MFO) system for rocket experiment is presented Theoretical study of the multi-foil wide-field X-ray “Lobster eye” based optics addresses the X-ray monitoring for astrophysical applications. Previous Developments and Tests of Small X-ray Optical Systems for Space Applications in collaboration with Pennsylvania State University, Department of Astronomy and Astrophysics (REX I) were continued. A novel approach (REX II) based on the use of MFO optics in combination with quad Timepix X-ray detector and X-ray spectrometer is proposed and studied. MFO X-ray telescope is designed especially for the Water Recovery REX II sub-orbital rocket experiment. A designed optical system combined with Timepix X-ray detectors is described.

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.

The LOBSTER telescopes are based on the optical arrangement of the lobster eye. The main difference from classical X-ray space telescopes in wide use is the very large field of view while the use of optics results in higher efficiency if compared with detectors without optics. Recent innovative technologies have enabled to design, to develop and to test first prototypes. They will provide deep sensitive survey of the sky in X-rays for the first time which is essential for both long-term monitoring of celestial high-energy sources as well as in understanding transient phenomena. The technology is now ready for applications in space.

The paper presents the X-ray Multi-Foil Optical (MFO) system proposed for the CubeSat demonstrator. The Lobster Eye (LE) design represents wide field of view (FOV) X-ray optics. This feature is unique in comparison with classical Wolter types of X-ray optics that reaches a field of view of typically 1 degree or less. LE optics can theoretically achieve an unlimited field of view, but for practical reasons, modules with, for example, 6 deg x 6 deg large FOV can be designed, developed, and constructed. Presented theoretical study of the Multi-Foil wide-field X-ray "Lobster eye" based optics shows effects of focal length, foil spacing and reflective surface (Au versus Ir). The main parameters that have been compared are effective area, gain, FWHM and/or transmission. The system can be used as an all-sky monitor in future projects.

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 degrees C to +80 degrees 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.

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 505km 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. Anovel 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.

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.

The use of COTS components is increasing on mainstream projects for both cost and performance reasons. However, the use of COTS has its dis-advantages such as traceability, obsolescence, cost increase due to up-screening etc. An ESA COTS Steering Committee has been set up in 2018 with the following mandate: “Bring together all ESA stake holders related to COTS based development, COTS end users, testing facilities and standards/specification entities in order to manage the evolution of the use of COTS in a coordinated manner in ESA’s current and future programmes, and in support to industrial requests”. In this lecture, the basics of radiation hardness assurance will be introduced. Test methods and applicable standards for total ionizing dose, displacement damage and single event effects testing will be presented. The usage of COTS in ESA space programs will be discussed as well as ESA’s current approach and timeline on COTS. Considerations and RHA best practices for COTS will be proposed. Application examples will be presented. References • ECSS-Q-ST-60-15C: Radiation Hardness Assurance – EEE components • ECSS-E-HB-10-12A: Calculation of radiation and its effects and margin policy handbook • ECSS-Q-ST-60C: Electrical, Electronic, Electromechanical (EEE) components • ESCC22900 (Iss5): Total dose steady-state irradiation test method • ESCC25100 (Iss2): Single Event Effects Test Method and Guidelines • NSREC conference 2017 Short Course • ESCCON conference 2019 Session: Space Radiation Environment RADHARD 2019 Symposium, April 9th 10th, 2019, Seibersdorf, Austria 11 Space Radiation Environment at LEO, MEO and GEO Christoph Tscherne1, Peter Beck1, Marcin Latocha1, Michael Wind1 1 Seibersdorf Labor GmbH, Austria Abstract Spacecraft in near-Earth orbits are exposed to a complex and harsh radiation environment that poses a great challenge to space mission design. Radiation accelerates the aging of EEE components, eventually leading to a decrease in performance or to a complete loss of functionality [1]. In order to face these challenges, it is necessary to understand the nature and effects of space radiation. The space radiation environments at Low Earth Orbits (LEO), Medium Earth Orbits (MEO) and Geostationary Earth Orbits (GEO) compose of three main types of primary radiation: Solar energetic particles (SEP), galactic cosmic radiation (GCR) and charged particles trapped in the Earth’s magnetic field [2, 3]. All three types are of different origin, vary greatly in energy and flux and underlie short-term and long-term variations modulated by the sun’s activity [4]. The presentation introduces the different types of orbits and discusses the origin and effects of the space radiation environment at LEO, MEO and GEO in detail. Characteristics of SEP, GCR and trapped particles are described and their influence on mission design and radiation hardness assurance (RHA) is reviewed [5, 6, 7].Spacecraft in near-Earth orbits are exposed to a complex and harsh radiation environment that poses a great challenge to space mission design. Radiation accelerates the aging of EEE components, eventually leading to a decrease in performance or to a complete loss of functionality [1]. In order to face these challenges, it is necessary to understand the nature and effects of space radiation. The space radiation environments at Low Earth Orbits (LEO), Medium Earth Orbits (MEO) and Geostationary Earth Orbits (GEO) compose of three main types of primary radiation: Solar energetic particles (SEP), galactic cosmic radiation (GCR) and charged particles trapped in the Earth’s magnetic field [2, 3]. All three types are of different origin, vary greatly in energy and flux and underlie short-term and long-term variations modulated by the sun’s activity [4]. The presentation introduces the different types of orbits and discusses the origin and effects of the space radiation environment at LEO, MEO and GEO in detail. Characteristics of SEP, GCR and trapped particles are described and their influence on mission design and radiation hardness assurance (RHA) is reviewed [5, 6, 7]. References [1] Poivey, Christian. „Total Ionizing and Non-Ionizing Dose Radiation Hardness Assurance.“ Short Course of NSREC 2017, 17 July 2017, New Orleans. USA. Presentation. [2] Holmes-Siedle, Andrew G., and Len Adams. Handbook of radiation effects. 2nd ed., Oxford University Press, 2002. [3] Santin, Giovanni. „Radiation Environments: Space, Avionics, Ground and Below.“ Short Course of RADECS 2017, 2 Oct. 2017, Geneva. Switzerland. Presentation. [4] Viereck, Rodney. „Space Weather: What is it? How Will it Affect You?“ NOAA Space Environment Center, 2007, Boulder Colorado. USA. Presentation. [5] ECSS-Q-ST-60-15C. “Radiation hardness assurance – EEE components”, October 2012 [6] ECSS-E-ST-10-04C. “Space Environment”, November 2008 [7] SPENVIS The European Space Agency (ESA) Space Environment Information System (SPENVIS), available online at http://swe.ssa.esa.int/; https://www.spenvis.oma.be/

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.

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.