Arthur B. C. Walker

Stanford University

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Richard B. Hoover

U.S. Space and Rocket Center

Troy W. Barbee

Lawrence Livermore National Laboratory

Joakim F. Lindblom

Stanford University

Phillip C. Baker

OptiScan (United States)

Maxwell J. Allen

Varian Medical Systems (United States)

C. E. DeForest

Southwest Research Institute

Ray H. O'Neal

Florida Agricultural and Mechanical University

C. C. Kankelborg

Montana State University

J. G. Timothy

Binus University

Troy W. Barbee

Lawrence Livermore National Laboratory

Cooperative Institutions

Stanford University

Lawrence Livermore National Laboratory

Goddard Space Flight Center

Marshall Space Flight Center

National Institute of Standards and Technology

University of California, Berkeley

Lockheed Martin (United States)

University of Alabama in Huntsville

Jet Propulsion Laboratory

Lawrence Berkeley National Laboratory

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Solar/stellar coronal explorer and the solar/stellar coronal observatory

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE (1992)

Arthur B. C. Walker Joakim F. Lindblom J. G. Timothy Troy W. Barbee Richard B. Hoover

The Solar/Stellar Coronal Explorer (SSCE) carries six identical Ritchey-Chretien Telescopes of 127 mm aperture each; their images will be recorded by multianode microchannel-array detectors. The mirrors of five of the telescopes are coated with multilayer reflecting structures that select narrow XUV wavelength bands corresponding to strong emission lines emitted by solar or stellar coronal plasmas. Also noted here is a larger explorer mission concept, that of the Solar/Stellar Coronal Observatory, which will undertake more extensive spectroscopic observations.

Corona (planetary geology)

Solar observatory

Coronal loop

Extreme ultraviolet

Coronal hole

10.1117/12.51237

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Citations (0)

The Advanced Solar Observatory

Optical Engineering (1990)

Arthur B. C. Walker Wayne L. Bailey Edward L. Chupp H. S. Hudson Ronald L. Moore

We describe a conceptual plan for the development of a comprehensive long duration solar space observatory, the Advanced Solar Observatory (ASO). The ASO is intended to provide solar astronomers with the observational power (spectral, spatial, and temporal resolution, sensitivity, and breadth of wavelength coverage) necessary to address fundamental problems relating to the solar convection zone and activity cycle, the thermal and nonthermal processes that control the transport of energy, mass, and magnetic flux in the solar atmosphere, the generation of the solar wind, and the dynamics of the inner heliosphere. The ASO concept encompasses three proposed space station based instrument ensembles: (i) the High Resolution Telescope Cluster, which includes far ultraviolet, extreme ultraviolet, and x-ray telescopes, (ii) the Pinhole/Occulter Facility, which includes Fourier transform and coded aperture hard x-ray and gamma ray telescopes and occulted ultraviolet and visible light coronagraphs, and (iii) the High Energy Facility, which contains neutron, gamma ray, and low frequency radio spectrometers. Two other facilities, the Orbiting Solar Laboratory, which will contain high resolution visible and ultraviolet telescopes on a free-flying platform, and a package of Global Dynamics Instrumentation will, with the space station ensembles, form a comprehensive capability for solar physics. We describe the scientific program of the ASO, current instrument concepts for the space station based ASO instrument ensembles, and plans for their accommodation on the space station.

Heliosphere

Solar telescope

Solar observatory

10.1117/12.55729

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Citations (1)

Solar Physics (1997)

Maxwell J. Allen Hakeem M. Oluseyi Arthur B. C. Walker Richard B. Hoover Troy W. Barbee

Solar observatory

10.1023/a:1004955129119

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Citations (13)

Ultrahigh resolution XUV spectroheliograph

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE (1990)

Arthur B. C. Walker Joakim F. Lindblom J. G. Timothy Troy W. Barbee Richard B. Hoover

We describe a space borne solar observatory, the Ultra High Resolution XUV Spectroheliograph (UHRXS), which has been selected by NASA for flight among the initial scientific instruments to be placed on the space station "Freedom". The principal URRXS instruments are nine XUV multilayer Ritchey-Chretien Telescopes covering the spectral range from -70 to -350 A; each telescope is able to isolate line multiplets within a narrow wavelength interval which are excited over a narrow temperature range, providing full disk images of diagnostic quality covering structures in the solar atmosphere ranging in temperature from T .5O,OOO K (He II ). 304 A) to 20,000,000 K (Fe XXIV X 192 A). The XUV images will be recorded on high resolution 70 mm format film, allowing resolutions as high as 0. 1 arc second to be achieved for a 1.O field. The XUV images will be supplemented by; (i) full disk high resolution (O.1") far ultraviolet images in H I Ly a ( 1216 A) and C IV (X 1548/1550 A), (ii) full disk soft x-ray images in 4 bands in the interval ?X 6 -70 A and (iii) electronically recorded high resolution (;v&% >10,000) spectroheliograms in 2 XUV, 1 EUV (.'45O A to 1 100 A) and 2 FUV (-4 100 A to 1600 A) bands. The electronically recorded images will use the Multi-Anode Multi-Channel Array (MAMA) detector. We propose to utilize the resulting data sets to address fundamental problems related to the following solar phenomena: (i) the fine structure of the solar chromosphere/corona interface, (ii) the structure, energetics and evolution of high temperature coronal loops, (iii) the large scale structure and dynamics of the corona, including the solar wind interface, the magnetic filed, and coronal mass ejections, and (iv) solar flares, especially the pre-flare state, the impulsive release of energy, and the evolution of post-flare loops. Subject Terms: solar atmosphere, corona, soft x-ray (XUV), extreme ultraviolet (EUV), far ultraviolet (FUV), multilayer optics

Extreme ultraviolet

Extreme Ultraviolet Lithography

Spectral resolution

Solar flare

10.1117/12.19148

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Citations (0)

Interpretation of the X-Ray Spectra of Solar Active Regions

Springer eBooks (1975)

Arthur B. C. Walker

Corona (planetary geology)

10.1007/978-94-010-1802-9_10

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Citations (6)

Design of a Normal Incidence Multilayer Imaging X-Ray Microscope

Journal of X-Ray Science and Technology (1989)

David L. Shealy David R. Gabardi Richard B. Hoover Arthur B. C. Walker Joakim F. Lindblom

Normal incidence multilayer Cassegrain x-ray telescopes were flown on the Stanford/MSFC Rocket X-Ray Spectroheliograph. These instruments produced high spatial resolution images of the Sun and conclusively demonstrated that doubly reflecting multilay

Curved mirror

X-ray optics

X-ray telescope

Extreme Ultraviolet Lithography

Radius of curvature

10.3233/xst-1989-1207

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Citations (9)

Multi-Spectral Solar Telescope Array IX: quantitative measurements of the solar corona

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE (1995)

C. E. DeForest Arthur B. C. Walker Maxwell J. Allen Richard B. Hoover Troy W. Barbee

The Multi-Spectral Solar Telescope Array (MSSTA) is a rocket borne cluster of normal- incidence multilayer coated telescopes for the high-resolution study of the solar atmosphere and corona. In previous papers, we have described the design, calibration, and flight of the MSSTA, and reported qualitative results of those solar observations. In the present paper, we describe the MSSTA's measured quantitative instrument response to the optically thin solar coronal plasma, and present an example of the derivation of solar temperature and density diagnostic information from four photographic images obtained during the instrument's successful inaugural flight in 1991.

Corona (planetary geology)

Solar telescope

Rocket (weapon)

Coronal loop

Spectral resolution

10.1117/12.212596

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<title>Astronomical observations with normal incidence multilayer optics IV: selection of spectral lines</title>

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE (1994)

Arthur B. C. Walker J.D. Plummer Richard B. Hoover Troy W. Barbee

In previous papers, we reviewed the development of multilayer optics, the successful application of this new technology to astronomical observations, the evolution of astronomical multilayer optics instrumentation through several generations, and the matching of multilayer bandpasses to the coronal spectrum. These developments have resulted in the acquisition of sub-arc-second images of the sun in several wavelength bands, permitting solar structures to be simultaneously observed over temperatures prevailing in the chromosphere (approximately 10,000 K - 100,000 K), the transition region (approximately 100,000 K - 1,000,000 K) and the corona (> 1,000,000 K). In the present paper, we discuss the selection of spectral bandpasses that permit a set of isothermal coronal and chromospheric images of diagnostic quality to be formed.

Chromosphere

Corona (planetary geology)

Instrumentation

10.1117/12.193153

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Citations (0)

X-Ray Optics, Instruments, and Missions II

Richard B. Hoover Arthur B. C. Walker

Source

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Citations (12)

Chromospheric and Coronal Structure of Polar Plumes