المؤلفون: Krivonos, R., Tkachenko, A., Burenin, R., Filippova, E., Lapshov, I., Mereminskiy, I., Molkov, S., Pavlinsky, M., Sazonov, S., Gubarev, M., Kolodziejczak, J., O'Dell, S. L., Swartz, D., Zavlin, Vyacheslav E., Ramsey, B. D.

مصطلحات موضوعية: Astrophysics - Instrumentation and Methods for Astrophysics

الوصف: The Astronomical Roentgen Telescope X-ray Concentrator (ART-XC) is a hard X-ray telescope with energy response up to 30 keV, to be launched on board the Spectrum Roentgen Gamma (SRG) spacecraft in 2018. ART-XC consists of seven identical co-aligned mirror modules. Each mirror assembly is coupled with a CdTe double-sided strip (DSS) focal-plane detector. Eight X-ray mirror modules (seven flight and one spare units) for ART-XC were developed and fabricated at the Marshall Space Flight Center (MSFC), NASA, USA. We present results of testing procedures performed with an X-ray beam facility at MSFC to calibrate the point spread function (PSF) of the mirror modules. The shape of the PSF was measured with a high-resolution CCD camera installed in the focal plane with defocusing of 7 mm, as required by the ART-XC design. For each module, we performed a parametrization of the PSF at various angular distances Theta. We used a King function to approximate the radial profile of the near on-axis PSF (Theta<9 arcmin) and an ellipse fitting procedure to describe the morphology of the far off-axis angular response (9Comment: 16 pages, 10 figures, 5 tables, Accepted in Experimental Astronomy

الوصول الحر: http://arxiv.org/abs/1708.09783Test

المؤلفون: Liu, D., Hussey, D., Gubarev, M. V., Ramsey, B. D., Jacobson, D., Arif, M., Moncton, D. E., Khaykovich, B.

المصدر: Appl. Phys. Lett. 102, 183508 (2013)

مصطلحات موضوعية: Physics - Instrumentation and Detectors, Physics - Optics

الوصف: An achromatic cold-neutron microscope with magnification 4 is demonstrated. The image-forming optics is composed of nested coaxial mirrors of full figures of revolution, so-called Wolter optics. The spatial resolution, field of view, and depth of focus are measured and found consistent with ray-tracing simulations. Methods of increasing the resolution and magnification are discussed, as well as the scientific case for the neutron microscope. In contrast to traditional pinhole-camera neutron imaging, the resolution of the microscope is determined by the mirrors rather than by the collimation of the beam, leading to possible dramatic improvements in the signal rate and resolution.
Comment: To be published in Applied Physics Letters

الوصول الحر: http://arxiv.org/abs/1304.6065Test

المؤلفون: Khaykovich, B., Gubarev, M. V., Bagdasarova, Y., Ramsey, B. D., Moncton, D. E.

المصدر: Nucl. Instr. and Meth. A 631, 98 (2011)

مصطلحات موضوعية: Physics - Instrumentation and Detectors

الوصف: We demonstrate neutron beam focusing by axisymmetric mirror systems based on a pair of mirrors consisting of a confocal ellipsoid and hyperboloid. Such a system, known as a Wolter mirror configuration, is commonly used in x-ray telescopes. The axisymmetric Wolter geometry allows nesting of several mirror pairs to increase collection efficiency. We have implemented a system containing four nested Ni mirror pairs, which was tested by focusing a polychromatic neutron beam at the MIT Reactor. In addition, we have carried out extensive ray-tracing simulations of the mirrors and their performance in different situations. The major advantages of the Wolter mirrors are nesting for large angular collection, and aberration-free performance. We discuss how these advantages can be utilized to benefit various neutron scattering methods, such as imaging, SANS, and time-of-flight spectroscopy.

الوصول الحر: http://arxiv.org/abs/1204.3104Test

المؤلفون: O'Dell, S. L., Brissenden, R. J., Davis, W. N., Elsner, R. F., Elvis, M., Freeman, M., Gaetz, T., Gorenstein, P., Gubarev, M. V., Jerius, D., Juda, M., Kolodziejczak, J. J., Murray, S., Petre, R., Podgorski, W., Ramsey, B. D., Reid, P. B., Saha, T., Schwartz, D. A., Trolier-McKinstry, S., Weisskopf, M. C., Wilke, R. H. T., Wolk, S., Zhang, W. W.

مصطلحات موضوعية: Astrophysics - Instrumentation and Methods for Astrophysics

الوصف: High-energy astrophysics is a relatively young scientific field, made possible by space-borne telescopes. During the half-century history of x-ray astronomy, the sensitivity of focusing x-ray telescopes-through finer angular resolution and increased effective area-has improved by a factor of a 100 million. This technological advance has enabled numerous exciting discoveries and increasingly detailed study of the high-energy universe-including accreting (stellar-mass and super-massive) black holes, accreting and isolated neutron stars, pulsar-wind nebulae, shocked plasma in supernova remnants, and hot thermal plasma in clusters of galaxies. As the largest structures in the universe, galaxy clusters constitute a unique laboratory for measuring the gravitational effects of dark matter and of dark energy. Here, we review the history of high-resolution x-ray telescopes and highlight some of the scientific results enabled by these telescopes. Next, we describe the planned next-generation x-ray-astronomy facility-the International X-ray Observatory (IXO). We conclude with an overview of a concept for the next next-generation facility-Generation X. The scientific objectives of such a mission will require very large areas (about 10000 m2) of highly-nested lightweight grazing-incidence mirrors with exceptional (about 0.1-arcsecond) angular resolution. Achieving this angular resolution with lightweight mirrors will likely require on-orbit adjustment of alignment and figure.
Comment: 19 pages, 11 figures, SPIE Conference 7803 "Adaptive X-ray Optics", part of SPIE Optics+Photonics 2010, San Diego CA, 2010 August 2-5

الوصول الحر: http://arxiv.org/abs/1010.4892Test

المؤلفون: Christe, Steven, Shih, Albert, Dennis, Brian, Krucker, S., Saint-Hilaire, Pascal, Glesener, Lindsay, Gubarev, M., Ramsey, Brian, Woods, Tom, Caspi, Amir

مصطلحات موضوعية: FOXSI, Solar Physics, SMEX, Hard X-ray, Telescope

الوصف: We present the FOXSI (Focusing Optics X-ray Solar Imager) small explorer (SMEX) concept, a mission dedicated to studying particle acceleration and energy release on the Sun. FOXSI is designed as a 3-axis stabilized spacecraft in low-Earth orbit making use of state-of-the-art grazing incidence focusing optics combined with pixelated solid-state detectors, allowing for direct imaging of solar X-rays. The current design being studied features multiple telescopes with a 14 meter focal length enabled by a deployable boom. FOXSI will observe the Sun in the 3-80 keV energy range. The FOXSI imaging concept has already been tested on two sounding rocket flights, in 2012 and 2014 and on the HEROES balloon payload flight in 2013. FOXSI will image the Sun with an angular resolution of 8'', a spectral resolution of 0.8 keV, and sub-second temporal resolution. FOXSI is a direct imaging spectrometer with high dynamic range and sensitivity and will provide a brand-new perspective on energy release on the Sun. We describe the mission and its science objectives.

العلاقة: https://zenodo.org/record/55293Test; https://doi.org/10.5281/zenodo.55293Test; oai:zenodo.org:55293

الإتاحة: https://doi.org/10.5281/zenodo.55293Test
https://zenodo.org/record/55293Test

المؤلفون: Gubarev, M, Kolodziejczak, J. K, Griffith, C, Roche, J, Smith, W. S, Kester, T, Atkins, C, Arnold, W, Ramsey, B

مصطلحات موضوعية: Optics

الوصف: Future astrophysical missions will require fabrication technology capable of producing high angular resolution x-ray optics. A full-shell direct fabrication approach using modern robotic polishing machines has the potential for producing high resolution, light-weight and affordable x-ray mirrors that can be nested to produce large collecting area. This approach to mirror fabrication, based on the use of the metal substrates coated with nickel phosphorous alloy, is being pursued at MSFC. The design of the polishing fixtures for the direct fabrication, the surface figure metrology techniques used and the results of the polishing experiments are presented.

الوصول الحر: https://ntrs.nasa.gov/citations/20160007985Test

المؤلفون: Liu, D., Hussey, D. S., Gubarev, M. V., Ramsey, B. D., Jacobson, D., Arif, M., Moncton, D. E., Khaykovich, B.

المصدر: Applied Physics Letters ; volume 103, issue 23 ; ISSN 0003-6951 1077-3118

مصطلحات موضوعية: Physics and Astronomy (miscellaneous)

الإتاحة: https://doi.org/10.1063/1.4835175Test

المؤلفون: Gubarev, M, Ramsey, B, Zavlin, V, Swartz, D, Kolodziejczak, J, Elsner, R, Pavlinsky, M, Tkachenko, A, Lapshov, I

مصطلحات موضوعية: Astronomy

الوصف: Seven x-ray mirror modules are being fabricated at the Marshall Space Flight Center (MSFC) for the Astronomical Roentgen Telescope (ART) instrument to be launched on board of the Spektrum Roentgen Gamma (SRG) Mission. As they are completed, the modules are tested and calibrated at the MSFC's 104-m Stray Flight Facility. The results of these calibration measurements and comparisons with theoretical models will be presented.

الوصول الحر: https://ntrs.nasa.gov/citations/20140011611Test

المؤلفون: Gubarev, M, Ramsey, B, Elsner, R, O'Dell, S, Kolodziejczak, J, McCracken, J, Zavlin, V, Swartz, D, Kilaru, K, Atkins, C, Pavlinskiy, M, Tkachenko, A, Lapshov, I

مصطلحات موضوعية: Optics

الوصف: The Astronomical Roentgen Telescope (ART) instrument is a hard-x-ray instrument with energy response up to 30 keV that is to be launched on board of the Spectrum Roentgen Gamma (SRG) Mission. The instrument consists of seven identical mirror modules coupled with seven CdTe strip focal-plane detectors. The mirror modules are being developed at the Marshall Space Flight Center (MSFC.) Each module has approx. 65 sq. cm effective area and an on-axis angular resolution of 30 arcseconds half power diameter (HPD) at 8 keV. The current status of the mirror module development and testing will be presented.

العلاقة: ART-XC/SRG: Status of the X-ray Optics Development

الوصول الحر: https://ntrs.nasa.gov/citations/20140011780Test

المؤلفون: Pavlinsky, M, Akimov, V, Levin, V, Lapshov, I, Tkachenko, A, Semena, N, Buntov, M, Glushenko, A, Arefiev, V, Yaskovich, A, Sunyaev, R, Churazov, E, Gilfanov, M, Grebenev, S, Sazonov, S, Revnivtsev, M, Lutovinov, A, Molkov, S, Kudelin, M, Drozdova, T, Garanin, S, Grigorovich, S, Litvin, D, Lazarchuk, V, Roiz, I, Garin, M, Babyshkin, V, Lomakin, I, Menderov, A, Moskvinov, D, Gubarev, M, Ramsey, B, Kilaru, K, ODell, S. L, Kolodziejczak, J, Elsner, R

مصطلحات موضوعية: Astronomy

الوصف: Spectrum Roentgen Gamma (SRG) is an X-ray astrophysical observatory, developed by Russia in collaboration with Germany. The mission will be launched in March 2016 from Baikonur, by a Zenit rocket with a Fregat booster and placed in a 6-month-period halo orbit around L2. The scientific payload consists of two independent telescopes - a soft-x-ray survey instrument, eROSITA, being provided by Germany and a medium-x-ray-energy survey instrument ART-XC being developed by Russia. ART-XC will consist of seven independent, but co-aligned, telescope modules. The NASA Marshall Space Flight Center (MSFC) is fabricating the flight mirror modules for the ART-XC/SRG. Each mirror module will be aligned with a focal plane CdTe double-sided strip detectors which will operate over the energy range of 6-30 keV, with an angular resolution of less than 1′, a field of view of approximately 34′ and an expected energy resolution of about 10 percent at 14 keV.

الوصول الحر: https://ntrs.nasa.gov/citations/20140011792Test