The Experts below are selected from a list of 17640 Experts worldwide ranked by ideXlab platform
Daniele Spiga - One of the best experts on this subject based on the ideXlab platform.
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mirror module design of X Ray Telescopes of eXtp mission
Optics for EUV X-Ray and Gamma-Ray Astronomy IX, 2019Co-Authors: S Basso, Marta Civitani, Giovanni Pareschi, Daniele Spiga, G Sironi, G Tagliaferri, Juan Wang, Yanji Yang, Yong Chen, Lizhi ShengAbstract:The eXTP (enhanced X-Ray Timing and Polarimetry) mission is a Chinese science space mission developed in collaboration with many international countries. Devoted to observations in the X-Ray band, with imaging, spectroscopic, timing and polarimetry capabilities, is now entering phase B. The payload includes 9 Spectroscopic Focusing ArRay (SFA) and 4 Polarimetry Focusing ArRay (PFA) Telescopes. The SFA Telescopes, equipped with SDDs, have a spatial resolution of 1 arcmin, while the PFA Telescopes, equipped with imaging gas piXel photoelectric polarimeters, have a spatial resolution of 30 arcsec. Both optics work in the 0.5-10 keV range with a focal length of 5.25 m and a field of view of 12 arcmin. The technology used for the optics production is Nickel electroforming from super-polished mandrels, like many previous successful X-Ray missions. The reflecting coating is a double layer Au+C, which ensures optimal response at high and low energies. The PFA and SFA have the same optical design, in order to minimize the number of mandrels to be produced. In this paper, we present the optical design of these Telescopes assisted with Raytracing and a preliminary concept for the mechanical design supported by FEM simulation.
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analytical computation of stRay light in nested mirror modules for X Ray Telescopes
arXiv: Instrumentation and Methods for Astrophysics, 2016Co-Authors: Daniele SpigaAbstract:StRay light in X-Ray Telescopes is a well-known issue. Unlike Rays focused via a double reflection by usual grazing-incidence geometries such as the Wolter-I, stRay Rays coming from off-aXis sources are reflected only once by either the parabolic or the hyperbolic segment. Although not focused, stRay light may represent a major source of background and ghost images especially when observing a field of faint sources in the vicinities of another, more intense, just outside the field of view of the telescope. The stRay light problem is faced by mounting a pre-collimator in front of the mirror module, in order to shade a part of the reflective surfaces that may give rise to singly-reflected Rays. Studying the eXpected stRay light impact, and consequently designing a pre-collimator, is a typical Ray-tracing problem, usually time and computation consuming, especially if we consider that Rays propagate throughout a densely nested structure. This in turn requires one to pay attention to all the possible obstructions, increasing the compleXity of the simulation. In contrast, approaching the problems of stRay light calculation from an analytical viewpoint largely simplifies the problem, and may also ease the task of designing an effective pre-collimator. In this work we eXpose an analytical formalism that can be used to compute the stRay light in a nested optical module in a fast and effective way, accounting for obstruction effects.
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cold and hot slumped glass optics with interfacing ribs for high angular resolution X Ray Telescopes
Proceedings of SPIE, 2016Co-Authors: Marta Civitani, Bianca Salmaso, Giovanni Pareschi, Daniele Spiga, S Basso, M Ghigo, G Vecchi, Robert Banham, E Breuning, V BurwitzAbstract:The Slumped Glass Optics technology, developed at INAF/OAB since a few years, is becoming a competitive solution for the realization of the future X-Ray Telescopes with a very large collecting area, e.g. the approved Athena, with more than 2 m2 effective area at 1 keV and with a high angular resolution (5’’ HEW). The developed technique is based on modular elements, named X-Ray Optical Units (XOUs), made of several layers of thin foils of glass, previously formed by direct hot slumping in cylindrical configuration and then stacked in a Wolter-I configuration, through interfacing ribs. The latest advancements in the production of thin glass substrates may allow a great simplification of this process, avoiding the preforming step via hot slumping. In fact, the strength and the fleXibility of glass foils with thickness lower than 0.1 mm allow their bending up to very small radius of curvature without breaking. In this paper we provide an update of the project development, reporting on the last results achieved. In particular, we present the results obtained on several prototypes that have been assembled with different integration approaches.
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Simulating X-Ray Telescopes with McXtrace: a case study of ATHENA’s optics
Space Telescopes and Instrumentation 2016: Ultraviolet to Gamma Ray, 2016Co-Authors: Desiree Della Monica Ferreira, Daniele Spiga, Niels Jørgen Stenfeldt Westergaard, Sonny Massahi, Brian Shortt, Erik Knudsen, Finn Erland Christensen, Mathias Solstad, Kim LefmannAbstract:We use the X-Ray Ray-tracing package McXtrace to simulate the performance of X-Ray Telescopes based on Silicon Pore Optics (SPO) technologies. We use as reference the design of the optics of the planned X-Ray mission Advanced Telescope for High ENergy Astrophysics (ATHENA) which is designed as a single X-Ray telescope populated with stacked SPO substrates forming mirror modules to focus X-Ray photons. We show that is possible to simulate in detail the SPO pores and qualify the use of McXtrace for in-depth analysis of in-orbit performance and laboratory X-Ray test results.
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simulating X Ray Telescopes with mcXtrace a case study of athena s optics
Proceedings of SPIE, 2016Co-Authors: Desiree Della Monica Ferreira, Daniele Spiga, Niels Jørgen Stenfeldt Westergaard, Sonny Massahi, Brian Shortt, Erik Knudsen, Finn Erland Christensen, Mathias Solstad, Kim LefmannAbstract:We use the X-Ray Ray-tracing package McXtrace to simulate the performance of X-Ray Telescopes based on Silicon Pore Optics (SPO) technologies. We use as reference the design of the optics of the planned X-Ray mission Advanced Telescope for High ENergy Astrophysics (ATHENA) which is designed as a single X-Ray telescope populated with stacked SPO substrates forming mirror modules to focus X-Ray photons. We show that is possible to simulate in detail the SPO pores and qualify the use of McXtrace for in-depth analysis of in-orbit performance and laboratory X-Ray test results.
Ahsen M. Hussain - One of the best experts on this subject based on the ideXlab platform.
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Development of thermally formed glass optics for astronomical hard X-Ray Telescopes.
Optics express, 2000Co-Authors: William W. Craig, Finn Erland Christensen, Charles J. Hailey, Mario A. Jimenez-garate, David L. Windt, Fiona A. Harrison, Peter H. Mao, Ahsen M. HussainAbstract:The neXt major observational advance in hard X-Ray/soft gamma-Ray astrophysics will come with the implementation of Telescopes capable of focusing 10-200 keV radiation. Focusing allows high signal-to-noise imaging and spectroscopic observations of many sources in this band for the first time. The recent development of depth-graded multilayer coatings has made the design of Telescopes for this bandpass practical, however the ability to manufacture ineXpensive substrates with appropriate surface quality and figure to achieve sub-arcminute performance has remained an elusive goal. In this paper, we report on new, thermally-formed glass micro-sheet optics capable of meeting the requirements of the neXt-generation of astronomical hard X-Ray Telescopes.
Akihiro Furuzawa - One of the best experts on this subject based on the ideXlab platform.
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on ground calibration of the hitomi hard X Ray Telescopes
Journal of Astronomical Telescopes Instruments and Systems, 2018Co-Authors: Takuya Miyazawa, Akihiro Furuzawa, Hisamitsu Awaki, Hideyuki Mori, Hironori Matsumoto, Yasunori Babazaki, Tadatsugu Demoto, Ayako Bandai, Yoshito HabaAbstract:We present X-Ray characteristics of the Hard X-Ray Telescopes (HXTs) on board the Hitomi (ASTRO-H) satellite. Measurements were conducted at the SPring-8 BL20B2 beamline and the ISAS/JAXA 27-m beamline. The angular resolution defined by a half-power diameter was 1.9′ (HXT-1) and 2.1′ (HXT-2) at 8 keV, 1.9′ at 30 keV, and 1.8′ at 50 keV. The effective area was found to be 620 cm2 at 8 keV, 178 cm2 at 30 keV, and 82 cm2 at 50 keV per mirror module. Although the angular resolutions were slightly worse than the requirement (1.7′), the effective areas sufficiently eXceeded the requirements of 150 cm2 at 30 keV and 55 cm2 at 50 keV. The off-aXis measurements of the effective areas resulted in the field of view being 6.1′ at 50 keV, 7.7′ at 30 keV, and 9.7′ at 8 keV in diameter. We confirmed that the main component of the stRay X-Ray light was significantly reduced by mounting the precollimator as designed. Detailed analysis of the data revealed that the angular resolution was degraded mainly by figure errors of mirror foils, and the angular resolution is completely eXplained by the figure errors, positioning errors of the foils, and conical approXimation of the foil shape. We found that the effective areas were ∼80 % of the designed values below 40 keV, whereas they steeply decline above 40 keV and become only ∼50 % . We investigated this abrupt decline and found that neither the error of the multilayer design nor the errors of the incident angles induced by the positioning errors of the foils can be the cause. The reflection profile of each foil pair from the defocused image strongly suggests that the figure errors of the foils probably bring about the reduction in the effective areas at higher energies.
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hard X Ray Telescopes to be onboard astro h
Applied Optics, 2014Co-Authors: Hisamitsu Awaki, Akihiro Furuzawa, Yoshito Haba, Manabu Ishida, Hideyo Kunieda, Hironori Matsumoto, Yasunori Babazaki, Tadatsugu Demoto, Takayuki Hayashi, Ryo IizukaAbstract:The new Japanese X-Ray astronomy satellite, ASTRO-H, will carry two identical hard X-Ray Telescopes (HXTs), which cover the energy range of 5 to 80 keV. The HXT mirrors employ tightly nested, conically approXimated thin-foil Wolter-I optics, and the mirror surfaces are coated with Pt/C depth-graded multilayers to enhance the hard X-Ray effective area by means of Bragg reflection. The HXT comprises foils 120–450 mm in diameter and 200 mm in length, with a focal length of 12 m. To obtain a large effective area, 213 aluminum foils 0.2 mm in thickness are tightly nested confocally. The requirements for HXT are a total effective area of >300 cm2 at 30 keV and an angular resolution of <1.7′ in half-power diameter (HPD). Fabrication of two HXTs has been completed, and the X-Ray performance of each HXT was measured at a synchrotron radiation facility, SPring-8 BL20B2 in Japan. Angular resolutions (HPD) of 1.9′ and 1.8′ at 30 keV were obtained for the full Telescopes of HXT-1 and HXT-2, respectively. The total effective area of the two HXTs at 30 keV is 349 cm2.
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current status of astro h hard X Ray Telescopes hXts
Proceedings of SPIE, 2012Co-Authors: Hisamitsu Awaki, Akihiro Furuzawa, Yoshito Haba, Manabu Ishida, Hideyo Kunieda, Takayuki Hayashi, Ryo Iizuka, Kazunori Ishibashi, Masayuki Itoh, Tatsuro KosakaAbstract:ASTRO-H is an international X-Ray mission of ISAS/JAXA, which will be launched in 2014. One of the main characteristics of ASTRO-H is imaging spectroscopy in the hard X-Ray band above 10 keV. ASTRO-H will carry two identical Hard X-Ray Telescopes (HXTs), whose mirror surfaces are coated with Pt/C depth-graded multilayers to enhance hard X-Ray effective area up to 80 keV. HXT was designed based on the telescope on board the SUMIT balloon borne eXperiment. After feasibility study of the HXT design, the FM design has been deteremined. Mass production of the mirror shells at Nagoya University has been going on since August 2010, and production of mirror shells for HXT-1 was completed in March 2012. After the integation of X-Ray mirrors for HXT-1, we measured hard X-Ray performance of selected mirror shells for HXT-1 at a synchrotron radiation facility, SPring-8 beamline BL20B2. We will perform environment tests and ground calibarations at SPring-8 for HXT-1. In HXT-2, foil production is going on.
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development of ultra thin thermal shield for astro h X Ray Telescopes
Proceedings of SPIE, 2011Co-Authors: Yuzuru Tawara, Akihiro Furuzawa, Hisamitsu Awaki, Satoshi Sugita, Kenji Tachibana, Manabu Ishida, Yoshitomo Maeda, Mina OgawaAbstract:ASTRO-H is a general purpose X-Ray observatory scheduled for launch in 2014. Two soft X-Ray Telescopes (SXT) and two hard X-Ray Telescopes (HXT) will be onboard covering energy range of 0.2 -80 keV. Thermal control of the telescope is similar to that of Suzaku, using a thermal shield (TS) placed in front of the telescope and a electric heater attached on the telescope housing. Thus it is required for a TS to have high soft X-Ray transmission, low solar absorptance and a low infrared emissivity. To meet these requirement, TS should be made of thin plastic film coated by metal such as aluminum. Then most important property of TS is mechanical strength to survive various environments at the launch and in orbit. This paper describes designing of TS, method of TS production, various environmental conditions and tests, risk management of treatment of ultra-thin film of TS in the process of production, testing and assembling.
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current status of the pre collimator development for the astro h X Ray Telescopes
Proceedings of SPIE, 2010Co-Authors: Hideyuki Mori, Takuya Miyazawa, Akihiro Furuzawa, Yoshito Haba, Hisamitsu Awaki, Yuzuru Tawara, Manabu Ishida, Hideyo Kunieda, Shigeo Yamauchi, Yoshitomo MaedaAbstract:We present the current status of the pre-collimator for the stRay-light reduction, mounted on the ASTRO-H X-Ray Telescopes (XRT). Since the ASTRO-H XRTs adopt the conical approXimation of the Wolter-I type grazing incident optics, X-Rays from a source located far from the telescope boresight create a ghost image in the detector field of view (FOV) as a stRay light, and then reduce the signal-to-noise ratio even in the hard X-Ray band. We thus plan to mount the pre-collimator, which is comprised of cylindrical blades aligned with each primary mirror, onto the XRTs to remove the stRay light. While the pre-collimator for the Soft X-Ray Telescopes is designed by the similar principle adopted for the Suzaku pre-collimator, that for the Hard X-Ray Telescopes requires some trade-off studies to select an appropriate blade material. The HXT pre-collimator currently utilizes the aluminum blade with the 50 mm height and 150 μm thickness. We eXamined the observational effects by the hard X-Ray (> 10 keV) stRay light and the eXpected performance of the pre-collimator in some scientific cases, using a Ray-tracing simulator. We found that the Galactic center may be mostly covered with the stRay light from the well-known bright X-Ray sources. In addition, the fluX estimation of the eXtended X-Ray emission such as the Cosmic X-Ray Background is also found to have large (~ 30%) uncertainty due to the stRay light from the outside of the XRT FOV. The pre-collimator improves the situations; the stRay light covering the source-free region in the Galactic center can be reduced by half and the uncertainty of the fluX determination for the diffuse source decreases down to < 10%.
Laura Proserpio - One of the best experts on this subject based on the ideXlab platform.
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Development of mirrors made of chemically tempered glass foils for future X-Ray Telescopes
Experimental Astronomy, 2015Co-Authors: Bianca Salmaso, Claudia Brizzolari, Laura Proserpio, Mauro Ghigo, Marta Civitani, Stefano Basso, Giovanni Pareschi, Daniele Spiga, Yves SuppigerAbstract:Thin slumped glass foils are considered good candidates for the realization of future X-Ray Telescopes with large effective area and high spatial resolution. However, the hot slumping process affects the glass strength, and this can be an issue during the launch of the satellite because of the high kinematical and static loads occurring during that phase. In the present work we have investigated the possible use of Gorilla® glass (produced by Corning®), a chemical tempered glass that, thanks to its strength characteristics, would be ideal. The un-tempered glass foils were curved by means of an innovative hot slumping technique and subsequently chemically tempered. In this paper we show that the chemical tempering process applied to Gorilla® glass foils does not affect the surface micro-roughness of the mirrors. On the other end, the stress introduced by the tempering process causes a reduction in the amplitude of the longitudinal profile errors with a lateral size close to the mirror length. The effect of the overall shape changes in the final resolution performance of the glass mirrors was studied by simulating the glass foils integration with our innovative approach based on glass reinforcing ribs. The preliminary tests performed so far suggest that this approach has the potential to be applied to the X-Ray Telescopes of the neXt generation.
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The challenge of developing thin mirror shells for future X-Ray Telescopes
Optical Systems Design 2015: Optical Fabrication Testing and Metrology V, 2015Co-Authors: Thorsten Döhring, Laura Proserpio, Anita Winter, Manfred Stollenwerk, Qingqing Gong, Peter FriedrichAbstract:Previously used mirror technologies are not able to fulfil the requirements of future X-Ray Telescopes due to challenging requests from the scientific community. Consequently new technical approaches for X-Ray mirror production are under development. In Europe the technical baseline for the planned X-Ray observatory ATHENA is the radical new approach of silicon pore optics. NASA´s recently launched NuSTAR mission uses segmented mirrors shells made from thin bended glasses, successfully demonstrating the feasibility of the glass forming technology for X-Ray mirrors. For risk mitigation also in Europe the hot slumping of thin glasses is being developed as an alternative technology for lightweight X-Ray Telescopes. The high precision mirror manufacturing requires challenging technical developments; several design trades and trend-setting decisions need to be made and are discussed within this paper. Some new technical and economic aspects of the intended glass mirror serial production are also studied within the recently started interdisciplinary project INTRAAST, an acronym for "industry transfer of astronomical mirror technologies". The goal of the project, embedded in a cooperation of the MaX-Planck-Institute for eXtraterrestrial Physics and the University of Applied Sciences Aschaffenburg, is to master the challenge of producing thin mirror shells for future X-Ray Telescopes. As a first project task the development of low stress coatings for thin glass mirror substrates have been started, the corresponding technical approach and first results are presented.
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light weight glass mirror systems for future X Ray Telescopes
Proceedings of SPIE, 2013Co-Authors: Anita Winter, P Friedrich, Elias Breunig, V Burwitz, G Hartner, Benedikt Menz, Laura ProserpioAbstract:Future X-Ray Telescopes need to combine large collecting area with good angular resolution. In order to achieve these aims within the mass limit, light-weight materials are needed for mirror production. We are developing a technology based on indirect hot slumping of thin glass segments; this method enables the production of the parabolic and hyperbolic part of the Wolter type I mirrors in one piece. Currently we use a combination of a porous ceramic for the slumping mould and the glass type D263 for the mirror material. In this study we use glasses that have been polished on one side to remove thickness variations in the glass, in order to investigate their influence on the results. We describe the eXperimental set-up, the slumping process and the metrology methods. Finally we present the results of an X-Ray test of several integrated glass sheets, and give an outlook on future activities.
Manabu Ishida - One of the best experts on this subject based on the ideXlab platform.
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ground based X Ray calibration of the astro h hitomi soft X Ray Telescopes
Journal of Astronomical Telescopes Instruments and Systems, 2018Co-Authors: Ryo Iizuka, Manabu Ishida, Yoshitomo Maeda, Takayuki Hayashi, Kazuki Tomikawa, Takashi Okajima, Toshiki Sato, Naomichi Kikuchi, Yang SoongAbstract:We present the summary of the on-ground calibration of two soft X-Ray Telescopes (SXT-I and SXT-S), developed by NASA’s Goddard Space Flight Center (GSFC), onboard Astro-H/Hitomi. After the initial X-Ray measurements with a diverging beam at the GSFC 100-m beamline, we performed the full calibration of the X-Ray performance, using the 30-m X-Ray beamline facility at the Institute of Space and Astronautical Science of Japan Aerospace EXploration Agency in Japan. We adopted a raster scan method with a narrow X-Ray pencil beam with a divergence of ∼15″. The on-aXis effective area (EA), half-power diameter, and vignetting function were measured at several energies between 1.5 and 17.5 keV. The detailed results appear in tables and figures in this paper. We measured and evaluated the performance of the SXT-S and the SXT-I with regard to the detector-limited field-of-view and the piXel size of the paired flight detector, i.e., SXS and the SXI, respectively. The primary items measured are the EA, image quality, and stRay light for on-aXis and off-aXis sources. The accurate measurement of these parameters is vital to make the precise response function of the ASTRO-H SXTs. This paper presents the definitive results of the ground-based calibration of the ASTRO-H SXTs.
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eXamining the angular resolution of the astro h s soft X Ray Telescopes
Journal of Astronomical Telescopes Instruments and Systems, 2016Co-Authors: Toshiki Sato, Manabu Ishida, Yoshitomo Maeda, Takayuki Hayashi, Ryo Iizuka, Kazuki Tomikawa, Naomichi Kikuchi, Sho Kurashima, Nozomi NakaniwaAbstract:The international X-Ray observatory ASTRO-H was renamed “Hitomi” after launch. It covers a wide energy range from a few hundred eV to 600 keV. It is equipped with two soft X-Ray Telescopes (SXTs: SXT-I and SXT-S) for imaging the soft X-Ray sky up to ∼12 keV, which focus an image onto the respective focal-plane detectors: CCD camera (SXI) and a calorimeter (SXS). The SXTs are fabricated in a quadrant unit. The angular resolution in half-power diameter (HPD) of each quadrant of the SXTs ranges between 1.1 and 1.4 arc min at 4.51 keV. It was also found that one quadrant has an energy dependence on the HPD. We eXamine the angular resolution with “spot scan” measurements. In order to understand the cause of imaging capability deterioration and to reflect it to the future telescope development, we carried out spot scan measurements, in which we illuminate all over the aperture of each quadrant with a square beam 8 mm on a side. Based on the scan results, we made “maps” of image blurring and a focus position. The former and the latter reflect figure error and positioning error, respectively, of the foils that are within the incident 8 mm×8 mm beam. As a result, we estimated those errors in a quadrant to be ∼0.9 to 1.0 and ∼0.6 to 0.9 arc min, respectively. We found that the larger the positioning error in a quadrant is, the larger its HPD is. The HPD map, which manifests the local image blurring, is very similar from quadrant to quadrant, but the map of the focus position is different from location to location in each telescope. It is also found that the difference in local performance causes energy dependence of the HPD.
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hard X Ray Telescopes to be onboard astro h
Applied Optics, 2014Co-Authors: Hisamitsu Awaki, Akihiro Furuzawa, Yoshito Haba, Manabu Ishida, Hideyo Kunieda, Hironori Matsumoto, Yasunori Babazaki, Tadatsugu Demoto, Takayuki Hayashi, Ryo IizukaAbstract:The new Japanese X-Ray astronomy satellite, ASTRO-H, will carry two identical hard X-Ray Telescopes (HXTs), which cover the energy range of 5 to 80 keV. The HXT mirrors employ tightly nested, conically approXimated thin-foil Wolter-I optics, and the mirror surfaces are coated with Pt/C depth-graded multilayers to enhance the hard X-Ray effective area by means of Bragg reflection. The HXT comprises foils 120–450 mm in diameter and 200 mm in length, with a focal length of 12 m. To obtain a large effective area, 213 aluminum foils 0.2 mm in thickness are tightly nested confocally. The requirements for HXT are a total effective area of >300 cm2 at 30 keV and an angular resolution of <1.7′ in half-power diameter (HPD). Fabrication of two HXTs has been completed, and the X-Ray performance of each HXT was measured at a synchrotron radiation facility, SPring-8 BL20B2 in Japan. Angular resolutions (HPD) of 1.9′ and 1.8′ at 30 keV were obtained for the full Telescopes of HXT-1 and HXT-2, respectively. The total effective area of the two HXTs at 30 keV is 349 cm2.
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ground based X Ray calibration of the astro h soft X Ray Telescopes
Proceedings of SPIE, 2014Co-Authors: Ryo Iizuka, Manabu Ishida, Yoshitomo Maeda, Takayuki Hayashi, Kazuki Tomikawa, Toshiki Sato, Naomichi KikuchiAbstract:The X-Ray astronomy satellite Astro-H, planned to be launched in 2015, will have several instruments for covering a wide energy band from a few hundreds eV to 600 keV. There are four X-Ray Telescopes, and two of them are soft X-Ray Telescopes (SXTs) covering up to about 15 keV. One is for an X-Ray micro-calorimeter detector (SXS) and the other is for an X-Ray CCD detector (SXI). The design of the SXTs is a conical approXimation of the Wolter Type-I optics, which is also adopted for the Telescopes on the previous mission Suzaku launched in 2005. It consists 203 thin-foil reflectors coated with gold monolayer (2000 A) on the aluminum substrate (101.6 mm length) with the thickness of 0.15, 0.23 and 0.31 mm. These are nested confocally within the radius of 58 to 225 mm. The focal length of SXTs is 5.6 m. The weight is as light as ~ 43 kg per telescope. We present the current status of the calibration activity of two SXTs (SXT-1 and SXT-2). The developments of two SXTs were completed by NASA's Goddard Space Flight Center (GSFC). First X-Ray measurements with a diverging beam at the GSFC 100m beamline found an angular resolution at 8.0 keV to be 1.1 and 1.0 arcmin (HPD) for SXT-1 and SXT-2, respectively. The full characterization of the X-Ray performance has been now continuously calibrated with the 30m X-Ray beamline facility at the Institute of Space and Astronautical Science (ISAS) of Japan Aerospace eXploration Agency (JAXA) in Japan. We adopted a raster scan method with a narrow X-Ray pencil beam with the divergence of ~ 15". X-Ray characterization of the two SXTs has been measured from May and December 2013, respectively. In the case of SXT-1, the on-aXis effective area was approXimately 580, 445, 370, 270, 185 and 90 cm 2 at energies of 1.5, 4.5, 8.0, 9.4, 11.1 and 12.9 keV respectively. The effective area of SXT-2 is 2% larger than that of SXT-1 irrespective to X-Ray energy. The on-aXis angular resolution of SXT-1 was evaluated as 1.3 - 1.5 arcmin (HPD) in the 1.5 - 13 keV band. The resolution was slightly got worse at higher energies by ~ 0:3 arcmin. Otherwise, the resolution of SXT-2 is 1.2 arcmin, almost irrespective to X-Ray energy. The field of view (FOV) was ~ 16 arcmin at 1.5 keV, decreasing with increasing X-Ray energy, and became ~ 8 arcmin at 13 keV. The FOV is defined here as the full-width at half-maXimum (FWHM) of the vignetting curve. The X-Ray performance of SXT-1 and SXT-2 meets the system requirements. Because all the parameters of the SXT-2 is slightly better that of SXT-1, we adopted the SXT-2 telescope for the SXS detector of the Astro-H primary instrument with the narrow FOV.
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revealing a detailed performance of the soft X Ray Telescopes of the astro h mission
Proceedings of SPIE, 2014Co-Authors: Manabu Ishida, Yoshitomo Maeda, Takayuki Hayashi, Ryo Iizuka, Kazuki Tomikawa, Toshiki Sato, Naomichi KikuchiAbstract:The international X-Ray observatory, ASTRO-H is currently planed as launched in 2015. The ASTRO-H mission covers a wide energy range from a few hundreds eV to 600 keV. The two Soft X-Ray Telescopes (SXT- 1 and SXT-2) play a role to image the soft X-Ray sky up to ~12 keV in that range. Each of them focuses an image on the focal plane detectors of the CCD camera (SXI) and the calorimeter (SXS-XCS), respectively. In this paper, we present spot scan measurements of the two SXTs. The spot scan fully illuminates the telescope by mapping with the 8 mm by 8 mm beam and creates the ”maps” of the half power diameter (HPD) and the focal location of the focused image. We found variations of performance at local area of the telescope. Each of the spot images has different focal-location and different HPD. Moreover, we found that the map of the HPD is very similar from quadrant to quadrant, but the map of the focal location is different from quadrant to quadrant, from radius to radius, and from azimuthal angle to angle.
