Rare gases from stepwise heating of lunar rock 12013
He, Ne, Ar and Xe from stepwise heating of Apollo 12 lunar rock 12013, discussing radiogenic and spallation components and He 3 and Ne 21 cosmic ray exposure ages
Alexander, E. C., Jr.↗
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Exploratory tests on a downstream-cathode MPD thruster
Low power MPD arc thrustor performance with downstream cathode, using Xe propellant
Burkhart, J. A.↗
Photolysis of propyne at 1470 A
Atomic and molecular hydrogen yields of propyne photolysis at 1470 A Xe resonance line
De Carlo, V. J.↗
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.↗
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.↗
Liquid-filled proportional counter
Liquid Xe filled single wire proportional and multiple wire ionization chambers, measuring gain and time/spatial resolution properties
Alvarez, L. W.↗
Performance of a Brayton-cycle power conversion system using a helium-xenon gas mixture
Brayton cycle power conversion system using He-Xe gas mixture, discussing compressor net engine and turbine static efficiencies
Ream, L. W.↗
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.↗
Brayton heat exchange unit development program
A Brayton Heat Exchanger Unit (BHXU), consisting of a recuperator, a heat sink heat exchanger and a gas ducting system, was designed, fabricated, and tested. The design was formulated to provide a high performance unit suitable for use in a long-life Brayton-cycle powerplant. A parametric analysis and design study was performed to establish the optimum component configurations to achieve low weight and size and high reliability, while meeting the requirements of high effectiveness and low pressure drop. Layout studies and detailed mechanical and structural design were performed to obtain a flight-type packaging arrangement. Evaluation testing was conducted from which it is estimated that near-design performance can be expected with the use of He-Xe as the working fluid.
Morse, C. J.↗
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.↗
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.↗
Parent-body models for the formation of iron meteorites.
The iron meteorites appear to have formed by both igneous and non-igneous processes in asteroid-sized parent bodies. Evidence regarding the IIIA-IIIB irons (the most common iron meteorite group) favors their having originated as a central core, which experienced fractional crystallization during solidification. A reevaluation of available data does not confirm earlier reports of variable cooling rates within group IIIA. Members of group IA-IB contain chondritic silicates, have short I-Xe formation intervals and do not show evidence of fractional crystallization. They appear to have formed nonigneously by inhomogeneous agglomeration and accretion of solar nebular condensates.
Wasson, J. T.↗
A target design for irradiation of NaI at high beam current
A solution to the targetry problems encountered when the iodine nucleus is a target for cyclotron irradiation is given as a target design. A target based on this design was used in 30 microampere irradiations of 46 MeV alpha particles for one-half hour without significant damage. Such an irradiation produces 6 to 7 mCi of Cs-129. This target should also be considered for cyclotron production of the radioisotopes Cs-127, I-123, and Xe-127.
Blue, J. W.↗
Population inversion calculations using near resonant charge exchange as a pumping mechanism.
A theoretical study is conducted to investigate the possibility of obtaining inversions in a plasma of metals such as Mg, Ca, Sr, or Ba by charge exchange with inert gas ions. The gases considered include He, Ne, Xe, Ar, or N. The analysis uses rate equations to calculate the density of the various ion levels and an energy equation to calculate the electron temperature. Both charge exchange and electron collisional excitation of the various ion levels are considered.
Chubb, D. L.↗
A target design for irradiation of NaI at high beam current.
A solution to the targetry problems encountered when the iodine nucleus is a target for cyclotron irradiation is given as a new target design. A target based on this design has been used in 30 microampere irradiations of 46 MeV alpha particles for one-half hour without significant damage. Such an irradiation produces 6 to 7 mCi of Cs-129, an isotope useful in nuclear medicine. This target should also be considered for cyclotron production of the radioisotopes Cs-127, I-123, and Xe-127.
Blue, J. W.↗
Extinct lunar radio activities - Xenon from Pu-244 and I-129 in Apollo 14 breccias.
Two Apollo 14 breccias have been found to contain xenon from the spontaneous fission of 82 my Pu-244. A third contains 60 times as much fission xenon as local uranium can account for and is probably of similar character. One of the breccias shows a Xe-129 excess most likely due to the decay of 17 my I-129. That these components can be separated and identified at all implies that complete isotopic homogenization has not occurred over a period which encompasses both extinction of these radionuclides and compaction of the breccias into their final form. In this sense isotope pre-history has been preserved in some lunar breccias providing information that pre-dates the formation of the rock itself (as determined by conventional techniques).
Behrmann, C. J.↗
Applications of activation analysis to geochemical, meteoritic and lunar studies.
The application of activation analysis techniques to the analysis of cosmological materials, i.e., terrestrial, tektitic, meteoritic, and lunar matter, is reviewed. Elemental determinations can be made by instrumental fast-neutron and thermal-neutron activation analysis, photonuclear and charged-particle activation analysis, and by radiochemical neutron activation analysis. Partition-coefficient methods, autoradiography studies, gamma-gamma coincidence counting, and age determination by neutron activation are discussed. Attention is given to K-Ar and I-Xe dating of meteorites.
Showalter, D. L.↗