Lens changes in the rabbit from fractionated X-ray and proton irradiations
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Cleary, S. F.↗
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Contact-eutectic-lens fabrication technique
Method enables use of crystal or semiconductor materials with selective spectral-response characteristics (ultraviolet, visible, or infrared wavelengths) in fabrication of contact lenses, reading glasses, and photographic processing equipment.
Allen, F. G.↗
Collecting efficiency of a cylindrical mirror electron energy analyzer with pre-retarding lens
The electron collecting efficiency of a cylindrical mirror energy analyzer incorporating retardation of the electrons prior to analysis has been determined over the range 0 to 30 eV by two methods. The first method requires the use of a vacuum ultraviolet monochromator to produce monoenergetic electrons of different energies; the second method involves measuring the energy-brightness relationship of the retarding optics and should be applicable to any deflection analyzer with pre-retarding optics. The results of the two methods are compared and the limitations of the latter method are discussed.
Gardner, J. L.↗
Field distribution in a thin lens
Quasi-optical formulation gives an optical field distribution by computing only two terms. First term represents geometrical optics effect, and second term represents diffraction effect; thus, mathematical expression is simplified, and considerable computer time is saved.
Chi, C. H.↗
Large-scale Fresnel lens solar concentrator
Sun tracking solar collector using lightweight inexpensive acrylic lenses to concentrate sun's energy yields efficiency range of 50 percent at average fluid temperature of 125 C to 26 percent at 300 C.
Allums, S. L.↗
Assembly and testing of a 1.8 by 3.7 meter Fresnel lens solar concentrator
A project was initiated to establish a technical data base on line focusing acrylic Fresnel lenses for use in a solar collector system that could generate temperatures in the range of 200 C to 370 C. The effort was originally directed toward electric power generation in the 100 to 10,000 kWe range using a distributed collector approach. However, as the program progressed, it centered on the development of a concentrator/collector subsystem concept that could meet the general requirement of thermal delivery within the 200 C to 370 C range. The expanded list of possible applications includes commercial heating/cooling and industrial process heat as well as electric power generation.
Robertson, J. E.↗
Certification and verification for Northrup model NSC-01-0732 fresnel lens concentrating solar collector
Structural analysis and certification of the collector system is presented. System verification against the interim performance criteria is presented and indicated by matrices. The verification discussion, analysis, and test results are also given.
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Fresnel lens tracking solar collector
Commercial tracking collector that uses acrylic Fresnel lenses to focus Sunlight on copper absorber tubes was evaluated. Tests are documented in 16 page report.
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Wideband comet camera lens design
A quarter-meter diameter, modified Ritchey-Chretien camera is described for spacecraft-based observation of Halley's Comet. The system will operate over an unusually broad spectral region, from 0.1216 micron (the hydrogen Lyman-alpha line) to 1.1 microns using reflective primary and secondary mirror optics and a thin UV-grade lithium fluoride refractive element as a field corrector near the image plane. The f/12, 3000 mm focal length camera has a 0.4 deg full field of view for operation with a 15 x 15 mm charge-coupled device detector array. The UV-enhanced silicon CCD detector is a 1000 x 1000 array of 15 micron pixels which establishes the system resolution requirement. The optical design and performance are discussed, with an emphasis on the image analysis with respect to pixel resolution elements used for viewing extended objects such as comets.
Huber, E. D.↗
The atmosphere as a lens
The advent of manned satellites has made it possible for man to observe Earth from great distances. Many new phenomena have been discovered in the atmosphere. These are evidently caused by reflection, scattering or refraction of light on crystals and drops of water. It is possible to see small objects on the surface of Earth because of these anomalies.
Mazurov, G.↗
Fresnel-Lens/Heat-Storage System
Self-contained solar-thermal power-plant uses Fresnel lenses to deliver up to 100 kilowatts. Proposed 200-volt system uses about 800 Fresnel lenses.
Turner, R. H.↗
Lens-and-Detector Array for Spectrometer
Supporting structure alines lenses and serves as light baffle. Lenses and infrared detectors mounted together in cavities in electroformed plate. Plate and cavities maintain optical alinement while serving as light baffle and aperture stop.
Oberheuser, J.↗
The statistics of gravitational lenses - The distributions of image angular separations and lens redshifts
An analytical calculation is presented which determines the probability that the light from a distant quasar can be lensed by objects in a different redshift range. Three types of information are used to make the calculation: (1) the physical properties of the intervening scattering lenses; (2) the intrinsic properties of the quasars and (3) the selection procedures by which the quasar samples are acquired. A series of differential equations is given in which the probability is derived, and a number of recommendations are offered with respect to VLA and Space Telescope observations of quasars lensed in this way.
Turner, E. L.↗
Lens collimation and testing using a Twyman-Green interferometer with a self-pumped phase-conjugating mirror
Ordinarily Twyman-Green interferometers are employed testing optical elements. In a modification of the basic configuration, the ordinary mirror in the test arm is replaced with a self-pumped phase-conjugating mirror using a barium titanate crystal. It is shown that, with a redefinition of components, the new configuration permits retention and improvement of the optical element testing function while simultaneously serving as a sensitive test for collimation. The optical path difference resulting from the double pass in the original Twyman-Green interferometer approximately equals that of the single pass and phase conjugation in the modification.
Howes, W. L.↗
Spectroscopy of the extranuclear line-emitting regions associated with the gravitational lens system 2016 + 112
Moderate-resolution slit spectroscopy of the extended emission-line objects A1 and B1 located within 5 arcsec of the triple radio source 2016 + 112 shows that at least one is physically associated with the z = 3.273 quasar thought to be multiply imaged by a foreground galaxy. The data and theoretical models unanimously favor the identification of A1 and B1 with two separate clouds of ionized gas that lie within a few kiloparsecs of the primary A/B QSO and radio source. The available evidence does not support the view that they are multiple images of a single object or their classification as separate (companion) galaxies.
Schneider, D. P.↗
Lens Antenna For Mobile/Satellite Communication
Flat, compact antenna made of stripline elements aimed at fixed elevation angle but steered electronically in azimuth. Design simplified by maintaining fixed elevation and relying on width of beam to cover desired elevation range. Need for phase shifter at each radiating element eliminated by arranging elements in circles and feeding through stripline disks called "R-KR lenses". Used in Mobile/Satellite Service, antenna mounted on top of vehicle on Earth and used to keep transmitted and received antenna beams aimed approximately toward communication satellite.
Bodnar, D. G.↗
The triple radio source 0023 + 171 - A candidate for a dark gravitational lens
In the course of a radio-optical search for gravitational lenses, a multiple radio source, 0023 + 171, was discovered, which has two optical counterparts at z = 0.946 separated by 5 arcsec. Their redshifts are the same within the measurement error, and their optical spectra show the same emission lines with the same relative intensities. One interpretation of these measurements is that the images of 0023 + 171 are gravitationally lensed. However, because the radio morphology is complex and the optical objects are faint, the existing data cannot exclude another interpretation, i.e., that the components of 0023 + 171 are two physically associated radio galaxies or two components of a single galaxy. The only possible evidence in favor of a lensing object is extremely faint optical emission located approximately 1 arcsec from one of the images. If this multiple source is indeed gravitationally lensed, the combination of available data imply a mass-to-light ratio for the lensing matter equal to about 1000.
Hewitt, J. N.↗
A VLA gravitational lens survey
A VLA survey designed to detect gravitational lensing on sub-arc second and arc second scales is described, and preliminary results of radio data are presented. In particular, it is found that the density of matter in the form of a uniform comoving number density of 10 to the 11th - 10 to the 12th solar mass compact objects, luminous or dark, must be substantially less than the critical density. Data obtained for the radio source 1042+178 are briefly examined.
Hewitt, J. N.↗