Inert gases from Apollo 11 and Apollo 12 fines - Reversals in the trends of relative element abundances
Primordial Kr and Xe trapping as possible cause of element abundance trend reversal in Apollo 11 and 12 fines
Heymann, D.↗
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Adsorption on the Martian regolith
Mars regolith carbon dioxide, water and Kr adsorption, explaining diurnal brightness phenomena
Cannon, W. A.↗
Shock tube investigation of bromine dissociation rates in the presence of helium, neon, argon, krypton, and xenon
Bromine dissociation rates in presence of He, Ne, Ar, Kr and Xe, determining rate constant expressions from light absorption measurements behind incident shock waves
Warshay, W.↗
Lunar fines and terrestrial rock powders - Relative surface areas and heats of adsorption
Apollo 11 lunar fines and ground terrestrial mafic rock powders effective surface areas and heats of adsorption, using Brunauer-Emmett-Teller Kr adsorption method
Cannon, W. A.↗
Stepwise heating analyses of rare gases from pile-irradiated rocks 10044 and 10057
Ar, Kr and Xe emanation during stepwise heating of lunar rocks under slow neutron irradiation in pile, using mass spectroscopy
Davis, P. K.↗
Visible and near ultraviolet spectra of low- pressure rare-gas microwave discharges
Visible and near UV spectra of vacuum Ar, Kr and Xe microwave discharge lamps with magnesium fluoride windows
Bowman, R. L.↗
Nuclear tracks in lunar samples
An attempt is made to relate the appearance of an etched tract to the atomic number and velocity of the ion that left it using 10 MeV/nucleon Kr beams and 6 MeV/nucleon Zn beams. It was found that the etching rate along a tract in minerals and glass is a monototonic function of ionization rate thus, making particle identification possible. Results show the following were present in lunar samples: superheavy elements, cosmic rays with z greater than 26, and solar flare particles in Surveyor glass.
Price, P. B.↗
A case for catastrophic early degassing of the earth.
Evidence is given for the occurrence in early earth history of massive escape of volatiles from the interior of the earth to its surface, which must have had catastrophic proportions. The mechanism and time of this event are inferred from the abundances and distribution of volatiles in the atmosphere, hydrosphere and crust, and from meteorite studies, and geophysical and astronomical observations. This event is linked to the melting of the earth during accretion which resulted in the concentration of U, Th, K and Pb in the outermost portion of the earth and in virtually complete expulsion of nonradiogenic Ar, Ne and Kr from its interior.
Fanale, F. P.↗
Quenching of the B /super 2/Sigma-plus state of the CN radical.
The quenching of the B (super 2)Sigma-plus fluorescence from the CN radical has been studied as a function of the relative velocity of the quenching collision and the total pressure in the fluorescence cell. The rate constant for the quenching of the CN fragment by ICN vapor was found to be directly proportional to the relative velocity of the quenching collision. Electronic quenching was also observed for methane, diatomic hydrogen, Kr, and Ar.
Jackson, W. M.↗
Rare gas record in the largest Apollo 15 rock.
The results obtained from mass-spectrometry analyses of the noble gases He, Ne, Ar, Kr, and Xe in a 182-mg chip of the largest Apollo 15 rock 15555 are presented. The spallation krypton data indicate a well-shielded location through most of the time during which the rock was exposed to cosmic rays. Gas retention ages are estimated. No evidence for the presence of products from plutonium-244 or iodine-129 was found.
Marti, K.↗
Systematics in auroral energy spectra.
Observation of a systematic increase in the mean energy of auroral electrons as the total precipitated energy increases. The change in 4278-A N2(+) intensity from about 50 R to about 10 kR correlates better with the change in mean energy of the precipitating electrons than with the change in number flux. Nightside aurora that exhibit this property superimpose on a wide region of soft (less than or about equal to 1 keV) precipitation that extends from the equatorial boundary of aurora to well poleward of normal visible aurora. On the dayside, the soft 'cusp' precipitation generates the statistical oval, although there may be larger energy inputs equatorward of the oval.
Eather, R. H.↗
Rare gas studies in Luna 16-G-7 fines by stepwise heating technique - A low fission solar wind Xe.
Examination of He, Ne, Kr, and Xe in a dust sample (equal to or less than 125 micrometer) of Luna 16 in 12 temperature steps with especially small intervals in the low temperature range (80 C steps). The gas concentrations, as well as their relative abundances, are in general agreement with values reported by Vinogradov (1971) for Luna 16 and values found in Apollo 11 fines except for Ne. Comparison is made with various other experimental results. The solar wind Xe was lower in the fission-affected isotopes than was found in Apollo 11 fines and in the 1000 C fraction of the Pesyanoe meteorite as measured by Marti (1969). Air-Xe is interpreted as a fractional solar wind Xe with the composition found in this study.
Kaiser, W. A.↗
Foreign-gas broadening of nitrous oxide absorption lines.
We have measured the foreign-gas broadening coefficients for collisional broadening of lines in the nu-3 fundamental of N2O by He, Ne, Ar, Kr, Xe, H2, D2, and CH4. These coefficients, which give the ratio of the line-broadening ability of these gases to the line-broadening ability of N2, can be used with recent measurements and calculations of N2 broadening to obtain optical collision cross sections.
Tubbs, L. D.↗
Hydrogen formation in the photolysis of propyne at 1236 A.
A Kr resonance lamp was used in the investigations. All experiments were performed at 25 C and 0.2 torr of propyne. Between 5% and 25% of the propyne was decomposed in any one experiment. It was found that the addition of 25% C2D4 had no effect on the quantum yield of molecular hydrogen. This suggests that hydrogen formation in the photolysis of propyne at 1236 A occurs exclusively via a molecular process. Pressure effects on the distribution of isotopic hydrogen formed in the photolysis were also investigated.
Payne, W. A.↗
Brightness of forbidden O I lines and properties of shadow bands during the eclipse of 7 March 1970.
Results of two types of measurements made at a site in the center of the eclipse track during the total eclipse of Mar. 7, 1970. The O I forbidden 5577-A and 6300-A lines were measured looking vertically through the eclipse shadow. The intensities were approximately 1 kR, essentially the values obtained in recent rocket measurements of normal day airglow at altitudes above 100 km. This is consistent with the hypothesis that these lines originate primarily at altitudes well above the shadow from mechanisms which are not appreciably perturbed by the approaching shadow. Measurements were also made of the time variation of intensity of incident light during the shadow-band period before second contact. There are saw-tooth fluctuations with steep leading edges, as well as many high-frequency components of smaller amplitude. This time variation does not appear to be obviously related in a simple way to current theories of their production mechanisms, or to the visual appearance of shadow bands.
Kerr, D. E.↗
The Gas Exchange Experiment for life detection - The Viking Mars Lander.
The Gas Exchange Experiment of the Viking mission accepts a sample of Martian soil, incubates this soil with nutrient medium, and periodically samples the enclosed atmosphere over this soil for the gases H2, N2, O2, Kr, and CO2. These gases are analyzed by an automated gas chromatograph, and the data are transmitted to earth. The design of the experiment and the qualitative and quantitative changes, if any, of gas composition should allow conclusions to be made on the presence of life on Mars. Data and theory substantiating this approach are presented.
Oyama, V. I.↗
Noble gas studies on regolith materials from Apollo 14 and 15.
Abundances and isotopic compositions of the five stable noble gases, He, Ne, Ar, Kr, and Xe in soils and breccia were determined. The samples investigated included material from a range of depths in a trench and a core tube. Noble gas determinations were performed in a 6-inch all-metal mass spectrometer of high sensitivity. The grain size separates and stepwise heating experimental methods used give results that supplement each other. Calculated concentrations of spallation Xe-126 in many of the fines and gas-rich breccia are presented in a table. Bulk soil samples obtained by Apollo 14 show an inverse correlation of spallation Xe-126 with grain size.
Bogard, D. D.↗
Observations of the Helium II 304-A and Helium I 584-A atmospheric dayglow radiation.
Two photometers with bandpasses of 170 to 500 and 170 to 800 A were employed to observe dayglow emissions in the extreme ultraviolet (EUV) over an altitude range of 90 to 186 km. The emissions observed with these photometers are identified as resonantly scattered He I 584-A and He II 304-A radiations. At 186 km, 209 plus or minus 70 rayleighs of 584-A and 9.3 plus or minus 3.1 rayleighs of 304-A radiation were measured. These observations are compared with theoretical calculations of resonance scattering of solar emissions from geocoronal He and He(+). Using the Jacchia (1971) atmospheric model for He, it is found that the observed brightness of the 584-A emission requires that the solar 584-A line width be 0.014 plus or minus 0.004 A. In this model the maximum overhead brightness of 584-A dayglow would occur at 900 km, and its magnitude would be 1.9 plus or minus 0.6 kR. The authors' observation of 304-A brightness requires that the overhead column density of the He(+) ions be 4.2 x 10 to the 11th ions/sq cm column. This value is consistent with a constant-density plasmasphere model with a He(+) ion density of 320 ions/cu cm in the plasmasphere.
Kumar, S.↗