scholarly journals Thin Shell, Segmented X-Ray Mirrors

2010 ◽  
Vol 2010 ◽  
pp. 1-16 ◽  
Author(s):  
R. Petre
Keyword(s):  
Angular Resolution ◽  
Imaging System ◽  
Broad Band ◽  
Thin Foil ◽  
Substantial Improvement ◽  
High Angular Resolution ◽  
X Ray ◽  
Performance Improvements ◽  
Glass Substrates ◽  
Astronomical Imaging

Thin foil mirrors were introduced as a means of achieving high throughput in an X-ray astronomical imaging system in applications for which high angular resolution was not necessary. Since their introduction, their high filling factor, modest mass, relative ease of construction, and modest cost have led to their use in numerous X-ray observatories, including the Broad Band X-ray Telescope, ASCA, and Suzaku. The introduction of key innovations, including epoxy replicated surfaces, multilayer coatings, and glass mirror substrates, has led to performance improvements and in their becoming widely used for X-ray astronomical imaging at energies above 10 keV. The use of glass substrates has also led to substantial improvement in angular resolution and thus their incorporation into the NASA concept for the International X-ray Observatory with a planned 3 m diameter aperture. This paper traces the development of foil mirrors from their inception in the 1970s through their current and anticipated future applications.

scholarly journals NuSTAR observations of four nearby X-ray faint AGNs: low luminosity or heavy obscuration?

2020 ◽  
Vol 497 (1) ◽  
pp. 229-245 ◽  
Author(s):  
A Annuar ◽  
D M Alexander ◽  
P Gandhi ◽  
G B Lansbury ◽  
D Asmus ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Active Galactic Nuclei ◽  
Angular Resolution ◽  
Broad Band ◽  
Galactic Nuclei ◽  
Current Data ◽  
High Angular Resolution ◽  
X Ray ◽  
Ir Imaging ◽  
Nuclear Dust

ABSTRACT We present NuSTAR (Nuclear Spectroscopic Telescope Array) observations of four active galactic nuclei (AGNs) located within 15 Mpc. These AGNs, namely ESO 121-G6, NGC 660, NGC 3486, and NGC 5195, have observed X-ray luminosities of L2–10 keV,obs ≲ 1039 erg s−1, classifying them as low-luminosity AGN (LLAGN). We perform broad-band X-ray spectral analysis for the AGN by combining our NuSTAR data with Chandra or XMM–Newton observations to directly measure their column densities (NH) and infer their intrinsic power. We complement our X-ray data with archival and new high-angular resolution mid-infrared (mid-IR) data for all objects, except NGC 5195. Based on our X-ray spectral analysis, we found that both ESO 121-G6 and NGC 660 are heavily obscured (NH > 1023 cm−2; L2–10 keV,int ∼ 1041 erg s−1), and NGC 660 may be Compton thick. We also note that the X-ray flux and spectral slope for ESO 121-G6 have significantly changed over the last decade, indicating significant changes in the obscuration and potentially accretion rate. On the other hand, NGC 3486 and NGC 5195 appear to be unobscured and just mildly obscured, respectively, with L2–10 keV,int < 1039 erg s−1, i.e. genuine LLAGN. Both of the heavily obscured AGNs have Lbol > 1041 erg s−1 and λEdd ≳ 10−3, and are detected in high-angular resolution mid-IR imaging, indicating the presence of obscuring dust on nuclear scale. NGC 3486, however, is undetected in high-resolution mid-IR imaging, and the current data do not provide stringent constraints on the presence or absence of obscuring nuclear dust in the AGN.

scholarly journals Concept for an X-ray telescope system with an angular resolution booster

2019 ◽  
Vol 71 (5) ◽  
Author(s):  
Yoshitomo Maeda ◽  
Ryo Iizuka ◽  
Takayuki Hayashi ◽  
Toshiki Sato ◽  
Nozomi Nakaniwa ◽  
...  
Keyword(s):  
Angular Resolution ◽  
Imaging System ◽  
Signal To Noise Ratio ◽  
Effective Area ◽  
High Energy ◽  
High Angular Resolution ◽  
Coded Aperture ◽  
X Ray ◽  
Modulation Collimator ◽  
Mirror Focus

ABSTRACT We present a concept for an X-ray imaging system with a high angular resolution and moderate sensitivity. In this concept, a two-dimensional detector, i.e., an imager, is put at a slightly out-of-focus position of the focusing mirror, rather than just at the mirror focus, as in the standard optics, to capture miniature images of objects. In addition, a set of multi-grid masks (or a modulation collimator) is installed in front of the telescope. We find that the masks work as a coded aperture camera and that they boost the angular resolution of the focusing optics. The major advantage of this concept is that a much better angular resolution, having an order of 2–3 or more than in the conventional optics, is achievable, while a high throughput (large effective area) is maintained, which is crucial in photon-limited high-energy astronomy, because any type of mirrors, including lightweight reflective mirrors, can be employed in our concept. If the signal-to-noise ratio is sufficiently high, we estimate that angular resolutions at the diffraction limit of 4″ and 0.″4 at ∼7 keV can be achieved with a pair of masks at distances of 1 m and 100 m, respectively.

Development of thin-shell adaptive optics for high angular resolution x-ray telescopes

2008 ◽  
Author(s):  
Charlotte Feldman ◽  
Richard Willingale ◽  
Carolyn Atkins ◽  
Hongchang Wang ◽  
Peter Doel ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Thin Shell ◽  
Angular Resolution ◽  
High Angular Resolution ◽  
X Ray

scholarly journals Next generation astronomical x-ray optics: high angular resolution, light weight, and low production cost

2012 ◽  
Author(s):  
W. W. Zhang ◽  
M. P. Biskach ◽  
P. N. Blake ◽  
K.-W. Chan ◽  
J. A. Gaskin ◽  
...  
Keyword(s):  
Production Cost ◽  
Angular Resolution ◽  
High Angular Resolution ◽  
Light Weight ◽  
Next Generation ◽  
Ray Optics ◽  
X Ray

Fused silica segments: a possible solution for x-ray telescopes with very high angular resolution like Lynx/XRS

2017 ◽  
Author(s):  
Bianca Salmaso ◽  
Stefano Basso ◽  
Marta M. Civitani ◽  
Mauro Ghigo ◽  
Joanna Holyszko ◽  
...  
Keyword(s):  
Angular Resolution ◽  
Fused Silica ◽  
High Angular Resolution ◽  
X Ray ◽  
Very High

Harecxs Measurements of Elemental Disordering

2001 ◽  
Vol 7 (S2) ◽  
pp. 354-355
Author(s):  
Nestor J. Zaluzec ◽  
Katherine L. Smith
Keyword(s):  
Angular Resolution ◽  
Alpha Decay ◽  
High Angular Resolution ◽  
Crystalline Materials ◽  
X Ray ◽  
Geologic Time ◽  
The Past ◽  
Selected Area Electron Diffraction ◽  
Resolution Electron ◽  
High Level

It has been long known that orientation effects in crystalline materials can influence characteristic x-ray emission and microanalysis1-7. High Angular Resolution Electron Channeling X-ray Spectroscopy (HARECXS)6-7. a variation of ALCHEMI4-5, has been used at ANL for the last few years to investigate the effects of channeling on quantitative XEDS analysis of materials. More recently we have also been using HARECXS to carefully measure elemental disordering in a number of systems and have found that it can be used very successfully to elucidate the various stages of disorder.Perovskite (nominally CaTiO3) is a host phase for actinides in various wasteforms for the immobilization of high level radioactive nuclear waste. Over geologic time, alpha decay damage of the actinides in perovskite will cause displacive effects that influence the dimensional and chemical stability of the wasteform. in the past, the progression of damage has been studied by monitoring changes in selected area electron diffraction (SAED) patterns with increasing dose (e.g. 11).

Electron Channeling X-ray Microanalysis for Cation Configuration in Irradiated Magnesium Aluminate Spinel

1999 ◽  
Vol 589 ◽  
Author(s):  
S. Matsumura ◽  
T. Soeda ◽  
N. J. Zaluzec ◽  
C. Kinoshita
Keyword(s):  
Angular Resolution ◽  
Magnesium Aluminate ◽  
High Angular Resolution ◽  
X Rays ◽  
Magnesium Aluminate Spinel ◽  
X Ray ◽  
Electron Channeling ◽  
Resolution Electron ◽  
Practical Tool ◽  
Cation Arrangement

AbstractHigh angular resolution electron channeling x-ray spectroscopy (HARECXS) was examined as a practical tool to locate lattice-ions in spinel crystals. The orientation dependent intensity distribution of emitted x-rays obtained by HARECXS is so sensitive to lattice-ion configuration in the illuminated areas that the occupation probabilities on specific positions in the crystal lattice can be determined accurately through comparison with the theoretical rocking curves. HARECXS measurements have revealed partially disordered cation arrangement in MgO·nAl2O3 with n= 1.0 and 2.4. Most A13+ lattice-ions occupy the octahedral (VI) sites with 6-fold coordination, while Mg2+ lattice-ions reside on both the tetrahedral (IV) and the octahedral (VI) sites. The structural vacancies are enriched in the IV-sites. Further evacuation of cations from the IV-sites to the VI-sites is recognized in a disordering process induced by irradiation with 1 MeV Ne+ ions up to 8.9 dpa at 870 K.

The Huber G670 imaging-plate Guinier camera tested on beamline I711 at the MAX II synchrotron

2000 ◽  
Vol 33 (2) ◽  
pp. 394-396 ◽  
Author(s):  
Kenny Ståhl
Keyword(s):  
Angular Resolution ◽  
High Angular Resolution ◽  
Imaging Plate ◽  
Correction Factors ◽  
Synchrotron Source ◽  
X Ray ◽  
Synchrotron Beam ◽  
Unusual Combination ◽  
Low Symmetry ◽  
Collection Time

A Huber G670 imaging-plate Guinier powder diffraction camera has been tested at an X-ray synchrotron source. It was found to be a very potent tool, offering an unusual combination of high angular resolution and short data collection time, while using very small amounts of sample. Specifically, it was found that: (i) the angular resolution (full width at half-maximum) varies between 0.07 and 0.15° in 2θ without focusing,i.e.relying on a parallel synchrotron beam; (ii) with a readout and erasure cycle time of 15 s, it is possible to obtain Rietveld-refinable data within less than a minute for a low-symmetry zeolite refined with 82 parameters; (iii) special attention has to be given to calibration of the detector and some general geometrical correction factors should be included in the data reduction.

Cold and Hot Slumped Glass Optics with interfacing ribs for high angular resolution x-ray telescopes

2016 ◽  
Author(s):  
M. Civitani ◽  
S. Basso ◽  
M. Ghigo ◽  
G. Pareschi ◽  
B. Salmaso ◽  
...  
Keyword(s):  
Angular Resolution ◽  
High Angular Resolution ◽  
X Ray ◽  
Glass Optics
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