Results 101 to 110 of about 991 (130)

Aspheric grating for extreme ultraviolet astronomy

Applied Optics, 1978
A family of plane curves is developed which can diffract incident parallel rays to a point focus. These curves, termed diffractoidal curves, are rotated around an axis to produce surfaces of revolution correspondingly termed diffractoids, whose imaging properties for sources at infinity are studied by ray tracing in a few examples.
S O Kästner
exaly   +3 more sources

Selection of materials for soft x-ray (SXR) and extreme ultraviolet (EUV) filters for space astronomy and other applications

SPIE Proceedings, 1994
This paper briefly reviews the more traditional materials that have been used for Soft X-Ray (SXR) and Extreme Ultraviolet (EUV) filters and then discusses several applications where new multilayer combinations of materials are being employed. The new applications include projection lithography and the detection of Energetic Neutral Atom (ENA ...
Donald Mitchell, Bill R Sandel, Forbes R Powell   +2 more
exaly   +2 more sources

The Design Of An Echelle Spectrometer For Diffuse Extreme Ultraviolet/Far Ultraviolet Astronomy

Proceedings of SPIE, 1986
The novel, relatively high-resolution nebular spectrometer design presented incorporates a mechanical precollimator with an objective echelle grating that proceeds to a cross-dispensing Wadsworth configuration; the minimum feasible number of reflections is employed in order to maximize EUV sensitivity. The configuration, which is noted to be capable of
exaly   +2 more sources

Extreme ultraviolet astronomy

Planetary and Space Science, 1992
exaly   +2 more sources

Extreme Ultraviolet Astronomy

2003
This text describes the development of astronomy in the Extreme Ultraviolet (EUV) wavelength range, from the first rocket-based experiments in the late 1960s through to later satellite missions. Discussions of the results from important space projects are followed by an analysis of the contributions made by EUV astronomy to the study of specific groups
Martin A. Barstow, Jay B. Holberg
openaire   +1 more source

Ultrasmooth beryllium substrates for solar astronomy in extreme ultraviolet wavelengths

Applied Optics, 2019
The paper describes a multistage method of forming ultrasmooth substrates based on bulk beryllium. Such substrates are suggested to be used for multilayer extreme ultraviolet mirrors of spacecraft missions on solar corona investigations in the spectral range 17.1-58.4 nm. The technique for chemical nickel plating of the sample surface is described. The
N. I. Chkhalo, M. S. Mikhailenko, A. E. Pestov, V. N. Polkovnikov, M. V. Zorina, S. Yu. Zuev, D. S. Kazakov, A. V. Milkov, I. L. Strulya, V. A. Filichkina, A. S. Kozlov   +10 more
openaire   +2 more sources

Advanced materials for multilayer mirrors for extreme ultraviolet solar astronomy

Applied Optics, 2016
We provide an analysis of contemporary multilayer optics for extreme ultraviolet (EUV) solar astronomy in the wavelength ranges: λ=12.9-13.3  nm, λ=17-21  nm, λ=28-33  nm, and λ=58.4  nm. We found new material pairs, which will make new spaceborne experiments possible due to the high reflection efficiencies, spectral resolution, and long-term ...
S A, Bogachev, N I, Chkhalo, S V, Kuzin, D E, Pariev, V N, Polkovnikov, N N, Salashchenko, S V, Shestov, S Y, Zuev   +7 more
openaire   +2 more sources

Extreme Ultraviolet Astronomy

Scientific American, 1994
▪ Abstract Astronomical studies in the extreme ultraviolet (EUV) band of the spectrum were dismissed during the early years of space astronomy as impossible, primarily because of the mistaken view that radiation in this band would be absorbed by the interstellar medium.
openaire   +1 more source

Astronomy and the Extreme Ultraviolet Explorer satellite

Science, 1994
The extreme ultraviolet wave band (100 to 912 angstroms) was thought until recently to be useless to astronomy, primarily because the opacity of the interstellar medium would prevent observations at these wavelengths. However, the interstellar medium has been found to be markedly inhomogeneous in both density and ionization state and the sun is ...
openaire   +2 more sources

Innovations in Optical Technologies for Extreme Ultraviolet Astronomy

Space Optics for Astrophysics and Earth and Planetary Remote Sensing, 1988
Extreme ultraviolet (EUV) astronomy has been a late arrival to the scene of space astronomy. Part of the reason for this was an incorrect appraisal of incomplete astronomical knowledge, which lead to the belief that, intrinsically, this kind of astronomy could not be carried out.
openaire   +1 more source