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Malina, Roger F.

Publications and source records attributed to Malina, Roger F..

29 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1987

Telescience - Concepts and contributions to the Extreme Ultraviolet Explorer mission

It is shown how the contradictory goals of low-cost and fast data turnaround characterizing the Extreme Ultraviolet Explorer (EUVE) mission can be achieved via the early use of telescience style transparent tools and simulations. The use of transparent tools reduces the parallel development of capability while ensuring that valuable prelaunch experience is not lost in the operations phase. Efforts made to upgrade the 'EUVE electronics' simulator are described.

Marchant, Will↗
NASA NTRS1987

An overview of the extreme ultraviolet explorer and its scientific program

NASA's Extreme Ultraviolet Explorer (EUVE) will carry out an all-sky survey from 8 to 90 nm in four bandpasses; the limiting sensitivity will be between 2 to 3 orders of magnitude fainter than the hot white dwarf HZ 43. A deep survey will also be carried out along the ecliptic which will have a limiting sensitivity of 1 to 2 orders of magnitude fainter than the all-sky survey in the bandpass from 8 to 50 nm. The payload also includes a spectrometer which will be used to observe the brighter sources found in the surveys with a spectral resolution of 1 to 2 A.

Malina, Roger F.↗
NASA NTRS1987

Prospective EUV observations of hot DA white dwarfs with the EUV Explorer

The Extreme Ultraviolet Explorer (EUVE) will perform a high sensitivity EUV all-sky survey. A major category of sources which will be detected with the EUVE instruments consists of hot white dwarfs. Detailed preliminary studies of synthetic EUV observations of white dwarfs have been carried out using the predicted EUVE instrumental response functions. Using available information regarding space densities of white dwarfs and the distribution of neutral hydrogen in the interstellar medium, the numbers of DA white dwarfs which will be detectable in the different EUV bandpasses have been estimated.

Finley, David S.↗
NASA NTRS1986

Astrophysical data on 5 eV to 1 keV radiation from the radiative decay of fundamental particles - Current limits and prospects for improvement

Line emission from the decay of fundamental particles, integrated over cosmological distances, can give rise to detectable spectral features in the diffuse astronomical background between 5 eV and 1 keV. Spectroscopic observations may allow these features to be separated from line emission from the numerous local sources of radiation. The current observational status and existing evidence for such features are reviewed. No definitive detections of nongalactic line features have been made. Several local sources of background mask the features at many wavelengths and confuse the interpretation of the data. No systematic spectral observations have been carried out to date. Upcoming experiments which can be expected to provide significantly better constraints on the presence of spectral features in the diffuse background from 5 eV to 1 keV are reviewed.

Bowyer, Stuart↗
NASA NTRS1986

An extreme ultraviolet telescope with no soft X-ray response

While EUV grazing incidence telescopes of conventional design exhibit a substantial X-ray response as well as an extreme UV response, and existing bandpass filters for the transmission of radiation longward of 400 A also transmit soft X-rays, the grazing incidence telescope presented suppresses this soft X-ray throughput through the incorporation of a Wolter Schwarzschild Type II mirror with large graze angles. The desirable features of an EUV photometric survey telescope are retained. An instrument of this design will be flown on the EUE mission, in order to make a survey of the sky at wavelengths longer than 400 A.

Finley, David S.↗
NASA NTRS1986

The mirrors for the Extreme Ultraviolet Explorer

Flight mirrors for the Extreme Ultraviolet Explorer satellite are currently under fabrication. The grazing incidence metal mirrors are Wolter-Schwarzschild Type I and II and are figured by diamond turning. Imaging performance is excellent, with the figure after polishing for the best mirror being such that the full width-half maximum is 1.0 arc seconds and the half energy width is 8 arc seconds measured at visible wavelengths. Surface finish, as determined from scattering measurements in the extreme ultraviolet, is about 20 A rms.

Finley, David S.↗
NASA NTRS1986

A Penning discharge source for extreme ultraviolet calibration

A Penning discharge lamp for use in the calibration of instruments and components for the extreme ultraviolet has been developed. This source is sufficiently light and compact to make it suitable for mounting on the movable slit assembly of a grazing incidence Rowland circle monochromator. Because this is a continuous discharge source, it is suitable for use with photon counting detectors. Line radiation is provided both by the gas and by atoms sputtered off the interchangeable metal cathodes. Usable lines are produced by species as highly ionized as Ne IV and Al V. The wavelength coverage provided is such that a good density of emission lines is available down to wavelengths as short as 100A. This source fills the gap between 100 and 300A, which is inadequately covered by the other available compact continuous radiation sources.

Finley, David S.↗
NASA NTRS1986

Optical surface evaluation by soft X-ray scattering

During the fabrication of the mirrors for the Extreme Ultraviolet Explorer (EUVE), methods for evaluating the surface quality of the optics have been developed. Measurement of soft X-ray scattering profiles allows for the determination of the surface roughness and correlation lengths for highly polished metal surfaces. With this method, the surface parameters for one of the Wolter Schwarzschild type I mirrors that had been fabricated for the EUVE mission have been determined. The techniques employed, the theoretical basis for the method, and the data that had been taken are presented. The measurements show that the best mirrors have a surface roughness of 20A rms or less.

Green, James C.↗
NASA NTRS1986

Evaluation of gratings for the Extreme Ultraviolet Explorer

Extensive grating calibration facilities have been developed at the Space Sciences Laboratory at Berkley, which are now being used for the evaluation of the gratings for the spectrometer on the Extreme Ultraviolet Explorer. Measurements of efficiency scattering and imaging quality can be made at wavelengths from 44A to 2500A.

Mrowka, Stan↗