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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 163 records · Page 9
All sourcesNASA NTRSDOE OSTI
NASA NTRS1990

Instrumentation in astronomy VII; Proceedings of the Meeting, Tucson, AZ, Feb. 13-17, 1990

The topics discussed include IR detectors and instrumentation, detectors, other instrumentation, optical instrumentation, and space instrumentation. Papers are presented on the IR spectrometer/imager for the ESO VLT, the fiber-coupled high-resolution IR array spectrometer for the Kuiper Airborne Observatory, the Balloon-Borne Infrared Telescope for FIR spectroscopy, and a simple transputer-based CCD camera controller. Attention is given to CCD guidance system for William Herschel Telescope, the New Technology Telescope control/acquisition system as a prototype for the VLT, a control system for spincasting 8-m borosilicate honeycomb mirrors, echelle spectrographs for 8-m class telescopes, and fiber spectroscopy at Palomar Observatory. Other papers are on the Kitt Peak National Observatory fiber actuator device, a two-star photoelectric photometer, an ultrahigh-resolution XUV spectroheliograph, an optical monitor for X-ray satellites, and large-format electrographic and array detectors for a space Schmidt imaging telescope.

Crawford, David L.↗
NASA NTRS1982

Highly versatile computer-controlled television detector system

A description is presented of a television detector system which has been designed to accommodate a wide range of applications. It is currently being developed for use in X-ray diffraction, X-ray astrophysics, and electron microscopy, but it is also well suited for astronomical observations. The image can be integrated in a large, high-speed memory system, in the memory of a computer system, or the target of the TV tube or CCD array. The detector system consists of a continuously scanned, intensified SIT vidicon with scan and processing electronics which generate a digital image that is integrated in the detector memory. Attention is given to details regarding the camera system, scan control and image processing electronics, the memory system, and aspects of detector performance.

Kalata, K.↗
NASA NTRS1985

A normal incidence X-ray telescope sounding rocket payload

Progress is reported on the following major activities on the X-ray telescope: (1) complete design of the entire telescope assembly and fabrication of all front-end components was completed; (2) all rocket skin sections, including bulkheads, feedthroughs and access door, were specified; (3) fabrication, curing and delivery of the large graphite-epoxy telescope tube were completed; (4) an engineering analysis of the primary mirror vibration test was completed and a decision made to redesign the mirror attachment system to a kinematic three-point mount; (5) detail design of the camera control, payload and housekeeping electronics were completed; and (6) multilayer mirror plates with 2d spacings of 50 A and 60 A were produced.

Golub, L.↗
NASA NTRS1993

X ray, extreme and far ultraviolet optical thin films for space applications

Far and extreme ultraviolet optical thin film filters find many uses in space astronomy, space astrophysics, and space aeronomy. Spacebased spectrographs are used for studying emission and absorption features of the earth, planets, sun, stars, and the interstellar medium. Most of these spectrographs use transmission or reflection filters. This requirement has prompted a search for selective filtering coatings with high throughput in the FUV and EUV spectral region. Important progress toward the development of thin film filters with improved efficiency and stability has been made in recent years. The goal for this field is the minimization of absorption to get high throughput and enhancement of wavelength selection. The Optical Aeronomy Laboratory (OAL) at the University of Alabama in Huntsville has recently developed the technology to determine optical constants of bulk and film materials for wavelengths extending from x-rays (0.1 nm) to the FUV (200 nm), and several materials have been identified that were used for designs of various optical devices which previously have been restricted to space application in the visible and near infrared. A new design concept called the Pi-multilayer was introduced and applied to the design of optical coatings for wavelengths extending from x-rays to the FUV. Section 3 of this report explains the Pi-multilayer approach and demonstrates its application for the design and fabrication of the FUV coatings. Two layer Pi-stacks have been utilized for the design of reflection filters in the EUV wavelength range from 70 - 100 nm. In order to eliminate losses due to the low reflection of the imaging optics and increase throughput and out-of-band rejection of the EUV instrumentation we introduced a self-filtering camera concept. In the FUV region, MgF2 and LiF crystals are known to be birefringent. Transmission polarizers and quarterwave retarders made of MgF2 or LiF crystals are commercially available but the performances are poor. New techniques for the design of the EUV and FUV polarizers and quarterwave retarders are described in Section 5. X- and gamma-ray detectors rely on a measurement of the electron which is effected when a ray interacts with matter. The design of an x- and gamma-ray telescope to operate in a particular region of the spectrum is, therefore, largely dictated by the mechanism through which the rays interact. Energy selection and the focusing of the incident high energy rays can be achieved with spectrally selective high reflective multilayers. The design and spectral performance of narrowband reflective x-ray Pi-multilayers are presented in section 6.

Zukic, Muamer↗
NASA NTRS1979

Thermographic measurement of fatigue damage

The paper presents a thermographic technique developed to measure the extent of fatigue damage in composite materials during fatigue loading. It is noted that heat generated by cyclic loading of fatigue damaged material raises the surface temperature. These temperatures were measured with an infrared camera and were used as boundary conditions in a finite element heat transfer program, which has been developed especially to calculate the extent of the heat generation zone, and thereby to define the fatigue damage zone. It is reported that the finite element program was verified by comparing calculated heat generation with the actual heat generation for a simple heat transfer problem that had a closed form solution. Damage zones are calculated for several boron/epoxy fatigue specimens from thermograms of specimens. The calculated damage zones were compared with damage detected by C-scan, X-ray, and scanning electron microscope (SEM) examinations. It is concluded that the analysis was effective in locating the boundaries of the fatigue damage zones.

Whitcomb, J. D.↗
NASA NTRS1986

Solid state imagers and their applications; Proceedings of the Meeting, Cannes, France, November 26, 27, 1985

Topics treated include the use of semiconductor imagers in high energy particle physics, an X-ray image sensor based on an optical TDI-CCD imager, and an electron-sensitive CCD readout array for a circular-scan streak tube. Papers are presented on the pan-imager, high resolution linear arrays, the reduction of reflection losses in solid-state image sensors, a high resolution CCD imager module with swing operation, large area CCD image sensors for scientific applications, and new readout techniques for frame transfer CCDs. Consideration is given to advanced optoelectronical sensors for autonomous rendezvous/docking and proximity operations in space, the testing and characterization of CCDs for the Rosat star sensors, an advanced radial camera for the Hubble Space Telescope, and scanning or staring infrared imagers.

Declerck, Gilbert J.↗
NASA NTRS1972

Apollo 15 orbital science summary.

In this paper, summary results of the Apollo 15 orbital science payload are given, and some quick-look results of Apollo 16 are discussed. Geochemical instruments, consisting of gamma-ray, X-ray, and alpha particle spectrometers, have provided a chemical map of the lunar surface flown over by Apollo 15. The Laser Altimeter and frontside gravity data have shown some unexpected results with regard to the lunar shape, and provided new basis for understanding lunar mascons. A magnetometer, aboard the small subsatellite, has located magnetic anomalies principally on the lunar farside, and has shown that the small lunar magnetic field is smoother on the frontside than on the back. The mass spectrometer, in orbit aboard the Command and Service Modules, has measured unexpectedly large populations of molecules at orbital altitude (110 km), mostly due to spacecraft contamination. Two major camera systems have provided the first systematic metric quality photography and concurrent high resolution stereo coverage of the lunar surface.

Esenwein, G. F.↗
NASA NTRS1980

IUE observations of a luminous M supergiant that exhibits emission continuum in the far ultraviolet

IUE observations of the late-type M supergiant star TV Gem which reveal an intense continuum in the far ultraviolet are discussed. TV Gem was observed in low dispersion in November 1979 and in high and low dispersion in January 1980 by the short and long wavelength cameras of the IUE spectrometer. An essentially featureless UV continuum was obtained, with the exception of a number of broad absorption features in the short wavelength region. A comparison with ground-based observations indicates that at wavelengths greater than 3200 A the continuum emission is essentially due to the M1 supergiant, while at shorter wavelengths the continuum is dominated by a hot companion. The UV continuum can be explained by a B9 or A1 III-IV early companion approximately 2 to 3 magnitudes fainter than the M1 supergiant, or by an accretion disk formed by mass transfer from the extended envelope of the M1 primary onto the surface of a highly condensed secondary. Soft X-ray observations from HEAO 2 are suggested as a means to investigate these interpretations.

Michalitsianos, A. G.↗
NASA NTRS1985

Soft X-Ray Telescope (SXRT)

The soft X-ray telescope (SXRT) will provide direct images of the solar corona with spatial resolution of about 1 arcsecond. These images will show the global structure of the corona, the location and area of coronal holes, and the presence of even the smallest active regions and flares. The good spatial resolution will show the fine scale magnetic structure and changes in these phenomena. These observations are essential for monitoring, predicting, and understanding the solar magnetic cycle, coronal heating, solar flares, coronal mass ejections, and the solar wind. These observations complement those of the White Light Coronagraph and Ultra-Violet Coronal Spectrometer; the SXRT will detect active regions and coronal holes near the east limb, thereby giving a week or more of advanced warning for disturbed geomagnetic conditions at Earth. The instrument consists of a grazing incidence collecting mirror with a full disk film camera at the primary focus, and a secondary relay optic that feeds a CCD camera with a field of view about the size of an average active region.

Moore, R. L.↗
NASA NTRS1986

Soft X-ray telescope (SXRT)

The soft X-ray telescope (SXRT) will provide direct images of the solar corona with spatial resolution of about 1 arcsecond. These images will show the global structure of the corona, the location and area of coronal holes, and the presence of even the smallest active regions and flares. The good spatial resolution will show the fine scale magnetic structure and changes in these phenomena. These observations are essential for monitoring, predicting, and understanding the solar magnetic cycle, coronal heating, solar flares, coronal mass ejections, and the solar wind. These observations complement those of the White Light Coronagraph and Ultra-Violet Coronal Spectrometer; the SXRT will detect active regions and coronal holes near the east limb, thereby giving a week or more of advanced warning for disturbed geomagnetic conditions at Earth. The instrument consists of a grazing incidence collecting mirror with a full-disk film camera at the primary focus, and a secondary relay optic that feeds a CCD camera with a field of view about the size of an average active region.

Moore, R.↗
NASA NTRS1967

Method for X-ray study under extreme temperature and pressure conditions

Vacuum chamber environmental simulator and X ray camera are used to study the stability of various minerals in extreme environmental conditions. An ion pump creates the desired vacuum. Exact sample positioning is obtained with a bellows sealed linear motion feed-through. Temperature control is by means of fluid conductive heat transfer.

Paus, L. L.↗
NASA NTRS1974

Apollo scientific experiments data handbook

A brief description of each of the Apollo scientific experiments was described, together with its operational history, the data content and formats, and the availability of the data. The lunar surface experiments described are the passive seismic, active seismic, lunar surface magnetometer, solar wind spectrometer, suprathermal ion detector, heat flow, charged particle, cold cathode gage, lunar geology, laser ranging retroreflector, cosmic ray detector, lunar portable magnetometer, traverse gravimeter, soil mechanics, far UV camera (lunar surface), lunar ejecta and meteorites, surface electrical properties, lunar atmospheric composition, lunar surface gravimeter, lunar seismic profiling, neutron flux, and dust detector. The orbital experiments described are the gamma-ray spectrometer, X-ray fluorescence, alpha-particle spectrometer, S-band transponder, mass spectrometer, far UV spectrometer, bistatic radar, IR scanning radiometer, particle shadows, magnetometer, lunar sounder, and laser altimeter. A brief listing of the mapping products available and information on the sample program were also included.

Eichelman, W. F.↗
NASA NTRS1975

Long-term X-ray studies of Sco X-1

No modulation of the 3-6 keV X-ray intensity of Sco X-1 at a level of excess of 1% was observed at the optical period of .787313d. Evidence is found for shot-noise character in a large fraction of the X-ray emission. Almost all of the Sco X-1 emission can be synthesized in terms of approximately 200 shots per day, each with a duration of approximately 1/3 day. A pinhole camera was used to obtain data and the data were statistically analyzed.

Holt, S. S.↗
NASA NTRS1981

The Pinhole/Occulter Facility

A large occulting system in space can be used for high resolution X-ray observations and for large aperture coronagraphic observations in visible and UV light. The X-ray observations can combine high angular resolution in hand (10 keV) X-radiation with the high sensitivity of a multiple pinhole camera, and can permit sensitive observations of bremsstrahlung from nonthermal particles in the corona. The large aperture coronagraphs have two major advantages: high angular resolution and good photon collection. This will permit observations of small scale structures in the corona for the first time and will give sufficient counting rates above the coronal background rates for sensitive diagnostic analysis of intensities and line profiles for coronal structures in the solar wind acceleration region. The technical basis for performing observations with a large occulting system in these three wavelength ranges is described as well as a pinhole/occulter facility presently being considered for Spacelab. Some indications about future developments are included.

Hudson, H. S.↗
NASA NTRS1985

Three-dimensional and tomographic imaging device for X-ray and gamma-ray emitting objects

An instrument for obtaining quantitative, three-dimensional and tomographic information relating to X-ray and gamma-ray emitting objects and for the orthoscopic viewing of such objects includes a multiple-pinhole aperture plate held spaced from an X-ray or gamma-ray to visible-light converter which is coupled to a visible-light image intensifier. The spacing between the aperture plate and the converter is chosen such that the mini-images of an emitting object formed by the pinholes do not substantially overlap as they impinge on the converter. The output of the image intensifier is digitized by a digitizing camera in terms of position and intensity and fed into a digital computer. The computer may output quantitative information relating to the emitting object directly, such as that relating to tomograms, or provide information in analogue form when coupled with a suitable viewing device to give an orthoscopic, three-dimensional image of the object.

Yin, L. I.↗
NASA NTRS1987

The AXAF high resolution camera (HRC) and its use for observations of distant clusters of galaxies

The High Resolution Camera being developed for AXAF is briefly described, comparing it with its predecessor, the Einstein HRI, and providing preliminary performance data. The HRC is a 10 cm x 10 cm detector with CsI coated microchannel plates providing a large field of view device with high X-ray quantum efficiency. The overall sensitivity of the HRC on AXAF is about 50 times that of the Einstein HRI. An example of the power of this instrument is discussed in the context of studies of distant clusters of galaxies. The HRC can detect individual galaxies in a cluster of redshift 1, if they are similar to the early-type galaxies in nearby clusters that have been observed by the Einstein instruments. The HRC will be used to measure the luminosity function for clusters of galaxies as a function of their distance up to a redshift of 1. This will allow observation of evolutionary effects in clusters as a whole, while the detection of individual galaxies will permit studies of galaxy evolution in a cluster environment.

Murray, S. S.↗
NASA NTRS1993

A ROSAT Wide Field Camera search for XUV bursts

We have searched the ROSAT Wide Field Camera all-sky survey for shorttime-scale (less than 50 s) XUV bursts down to a limiting count of 5 x 10 exp -3 count/sq arcmin, corresponding to an incident flux of about 3 x 10 exp -10 erg/sq cm. In a total observation period of 171 d covering the entire sky, we found no evidence for such events. The present results are used to place limits on the log N-log S relation for gamma-ray bursts and constraints on the spectral shape of the previously reported ultrasoft X-ray transients.

Owens, Alan↗