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At least 487 records · Page 27

High resolution portable holocamera

High resolution portable hologram recording camera with pulsed ruby laser light source and rechargeable storage batteries as self contained power supply

Close, D. H.↗

An optical quality meter suitable for cryogenic liquids

Construction of instrument to measure ratio of liquid to gas of flowing transparent cryogenic fluid is described. Instrument consists of collimated light source and photoconductive cell. Operation of instrument is described and illustration of equipment is provided.

Hobart, H. F.↗

Experiment S030: Dim sky photography/orthicon

During Gemini missions, the image orthicon system was used to obtain photographic data on faint and diffuse astronomical phenomena. Results show that the photographs may be used to determine the airglow geometry. Although it was sensitive, the original photographic system was unsuitable for use in the study of dim and diffuse astronomical light sources.

Dunkelman, L.↗

Two new methods to increase the contrast of track-etch neutron radiographs

Methods for increasing the (optical density span) of radiographs were evaluated. In one method, fluorescent dye was deposited in the tracks of the radiograph. The radiograph was then examined under ultraviolet light. The second method was a crossed Polaroid filter technique. The radiograph was placed between the filters and then illuminated with a diffuse white-light source. An increase in the optical density span from .10 to .37 was obtained with the dye method. With the Polaroid method, the increase obtained was from .10 to 2.4.

Morley, J.↗

Spacecraft orientation and exposure to environment, Appendix A

Material removed from the spacecraft and returned to earth remained on the lunar surface for 31.9 lunations. None of the returned parts received the maximum 10,686 hours of exposure because of shadowing by the planar array antenna, solar panel, thermal control compartments, or other parts of the spacecraft. To determine the actual exposure of specific parts to sunlight, six series of photographs were taken. A one-fifth-scale model spacecraft was oriented to a collimated light source simulating the orientation of Surveyor with the sun. Three cameras were set up to view different parts of the spacecraft. The data obtained from these photographs permitted an evaluation of the effects of exposure to solar radiation on the camera and its parts, the surface sampling scoop, and the strut from the radar altimeter and Doppler velocity sensor.

Nickle, N. L.↗

Documentation of Apollo 15 samples

A catalog is presented of the documentation of Apollo 15 samples using photographs and verbal descriptions returned from the lunar surface. Almost all of the Apollo 15 samples were correlated with lunar surface photographs, descriptions, and traverse locations. Where possible, the lunar orientations of rock samples were reconstructed in the lunar receiving laboratory, using a collimated light source to reproduce illumination and shadow characteristics of the same samples shown in lunar photographs. In several cases, samples were not recognized in lunar surface photographs, and their approximate locations are known only by association with numbered sample bags used during their collection. Tables, photographs, and maps included in this report are designed to aid in the understanding of the lunar setting of the Apollo 15 samples.

Sutton, R. L.↗

Recent progress in the remote detection of vapours and gaseous pollutants

Work has been continuing on the correlation spectrometry techniques described at previous remote sensing symposiums. Advances in the techniques are described which enable accurate quantitative measurements of diffused atmospheric gases to be made using controlled light sources, accurate quantitative measurements of gas clouds relative to background using solar illumination and semi-quantitation measurements of well diffused atmospheric gases using solar illumination. Specific applications of these techniques are described including preliminary results of a high altitude balloon experiment designed to test the feasibility of measuring pollution at the earth's surface from high altitude balloons and satellites.

Moffat, A. J.↗

The optical properties of platinum and gold in the vacuum ultraviolet

The optical constants of platinum and gold thin films have been determined in the spectral region of 40 to 200 nm by reflection measurements. The highly polarized continuum of synchrotron radiation emitted by the 240-MeV electron storage ring at the Physical Sciences Laboratory of the University of Wisconsin was used as a light source for the spectrum below 120 nm, while a windowless discharge lamp coupled to a normal incidence monochromator provided a source for the longer wavelengths. Optical constants were determined by a computer program based on iterative solutions to the Fresnel equations for reflection as a function of the angle of incidence.

Linton, R. C.↗

Vacuum ultraviolet radiometry with a stabilized hydrogen arc.

Use of the spectral radiation emitted from a dense hydrogen plasma of at least 12,000 K, which is in local thermodynamic equilibrium (LTE), as a light source for vacuum UV radiometry. Its spectroscopic qualities are exactly known, and except for a few strongly Stark-broadened Lyman lines, its spectrum in the vacuum UV is essentially continuous. The calculated continuum output of this source for typical operating conditions is compared with the UV output of the tungsten strip lamp and the carbon arc.

Ott, W. R.↗

Photodetachment of electrons from phosphide ion - The electron affinity of PH2.

Measurement of the relative cross section for photodetachment of electrons from PH2(-) in the wavelength region 725 to 1020 nm (1.71 to 1.22 eV). An ion cyclotron resonance spectrometer was used to generate, trap, and detect the negative ions, and two light sources were employed to study photodetachment: a 1000-W xenon arc lamp with a grating monochromator and a continuously tunable laser. A single sharp threshold in the cross-section curve was observed, and a detailed analysis yielded an electron affinity value of 1.25 plus or minus 0.03 eV.

Smyth, K. C.↗

Photodetachment of electrons from amide and arsenide ions - The electron affinities of NH2., and AsH2.

The relative cross section for the gas-phase photodetachment of electrons has been determined for NH2(-) in the wavelength region of 1195 to 1695 nm and for AsH2(-) in the region from 620 to 1010 nm. An ion cyclotron resonance spectrometer was used to generate, trap, and detect negative ions. A 1000-W xenon arc lamp with a grating monochromator was used as the light source, except for one series of experiments in which a tunable laser was employed. Single sharp thresholds were observed in both cross sections, and the following electron affinity values were determined: 0.744 (plus or minus 0.022) eV for NH2. and 1.27 (plus or minus 0.03) eV for AsH2.

Smyth, K. C.↗

Photodetachment of an electron from selenide ion - The electron affinity and spin-orbit coupling constant for SeH.

The relative cross section for the gas phase photodetachment of an electron from SeH(-) was determined in the wavelength region 428 to 578 nm. An ion cyclotron resonance spectrometer was used to generate, trap, and detect the negative ions, and a 1000-W xenon arc lamp with a grating monochromator was employed as the light source. The cross section exhibited two sharp thresholds, whose positions remained unchanged for the photodetachment of SeD(-). As a result of these thresholds, the electron affinity and the spin-orbit coupling constant were evaluated.

Smyth, K. C.↗

Relative transition probabilities for krypton.

First experimental line strength data for the visible Kr II lines and for several of the more prominent Kr I lines are given. The spectroscopic light source used is the thermal plasma behind the reflected shock wave in a gas-driven shock tube. A 3/4-m spectrograph and a 1-m spectrograph were employed simultaneously to provide redundant photometry. The data are compared with other measurements and with theoretical calculations.

Miller, M. H.↗

On the temperature distribution in a planetary atmosphere.

Criteria for the appearance of a double maximum in the absorption spectra are derived. A very oversimplified model atmosphere which consists of two isothermal layers of gas is considered. The model involves the presence of two absorption cells in series, in front of a light source that has a higher temperature than either of the cells. The possibility that the double maximum is due to a quantum-mechanical interaction is studied. It is concluded that the effect reported by Kaplan (1962) was due to noise, and that it is impossible to detect temperatures as high as 700 K in the atmosphere of Venus by means of ground-based observations of the 7820 A carbon dioxide band.

Young, L. D. G.↗

An extreme ultraviolet photometer for solar observations from the Atmosphere Explorer satellites

A broadband photometer experiment is being fabricated for the Atmosphere Explorer C, D and E missions to record the solar irradiance in the 40 to 1250 A region with seven distinct passbands. The experiment consists principally of four spinal electron multipliers located behind a moving eight position filter wheel. Six metallic filters are used to spectrally isolate the solar irradiance. In addition three Al2O3 diodes, two with filters, are being used to record the solar irradiance over the range of orbital altitudes from perigee through apogee. A principal goal of the experiment will be to measure time dependence of the solar irradiance with respect to a storage ring synchrotron light source which has been calibrated in terms of the best currently available standards of irradiance.

Heath, D. F.↗

Iron absorption band analysis for the discrimination of iron rich zones

The author has identified the following significant results. A lineament study of the Nevada test site is near completion. Two base maps (1:500,000) have been prepared, one of band 7 lineaments and the other of band 5 lineaments. In general, more lineaments and more faults are seen on band 5. About 45% of the lineaments appear to be faults and contacts, the others being predominantly streams, roads, railway tracks, and mountain crests. About 25% of the lineaments are unidentified so far. Special attention is being given to unmapped extensions of faults, groups of unmapped lineaments, and known mineralized areas and alteration zones. Earthquake epicenters recorded from 1869 to 1963 have been plotted on the two base maps. Preliminary examination as yet indicates no basic correlation with the lineaments. Attempts are being made to subtract bands optically, using an I2S viewer, an enlarger, and a data color viewer. Success has been limited so far due to technical difficulties, mainly vignetting and poor light sources, within the machines. Some vegetation and rock type differences, however, have been discerned.

Rowan, L. C.↗

Mariner Mars 1971 sun sensor model development and simulation

The sun sensor flight performance data were analyzed along with the results of a newly developed cruise sensor life in order to better understand cadmium sulfide sun sensor performance. A set of mathematical models was constructed which closely approximated the observed sun sensor flight and laboratory test results. These models revealed, among other things, that (1) the aging phenomena in the sintered cadmium sulfide light detector varies across the detector width in proportion to the illumination history, (2) the current cruise sun sensor design is extremely sensitive to changes in the reflected illumination within the sensor housing, (3) the reflected illumination within the detector housing is proportional to the area and intensity of the solar disk observed at the spacecraft, and (4) the acquisition sun sensor becomes a low impedance path across the sensor bridge when in the vicinity of a large-angular-diameter, low-intensity light source.

Schumacher, L.↗