Reduction and analysis of data from OGO-4 experiment 15 Final report, 1 Nov. 1969 - 30 Nov. 1970
Procedures for processing atmospheric composition data obtained through use of sweeping quadrupole mass spectrometer on OGO-4 satellite
Leite, R. J.↗
SEARCH · Engineering Papers
Results for “Quadrupole”
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Response of the neutral atmosphere to geomagnetic disturbances
Neutral atmospheric composition and density variations during geomagnetic disturbances from OGO-6 satellite quadrupole mass analyzer measurements
Carignan, G. R.↗
Thermal analysis-inorganic gas release studies of lunar samples
Thermal analysis-quadrupole mass spectrometric analyses on inorganic released gases of Apollo 11 and 12 samples and synthetic lunar analogs
Gibson, E. K., Jr.↗
The interaction of O(plus) ions with the interior surface of a copper chamber
Modulated beams of 0(+), Ar(+), and Kr(+) in the 100-300 eV range are directed into a copper box simulating the ante-chamber of an orbiting mass spectrometer. An RF quadrupole mass spectrometer and phase sensitive detection extract the component of the internal mass spectrum correlated with the beam. Intense Ar and Kr signals are observed; however, no O or O2 is detectable, indicating loss of the primary O(+) beam to surface interactions. All four primary ions stimulate sizeable signals at masses 26 and 28. The relevance of these experiments to the interpretation of mass spectra obtained by orbiting satellites is discussed.
Siegel, M. W.↗
Lunar mass spectrometer test program
The procedures used and the results are described, which were obtained in a test program to demonstrate the performance of a candidate lunar mass spectrometer. The instrument was designed to sample and measure gases believed to exist in the lunar atmosphere at the surface. The instrument consists of a cold cathode ion source, a small quadrupole mass analyzer, and an off-axis electron multiplier ion-counting detector. Instrument resolution, sensitivity, and S/N ratio were demonstrated over the mass range 0-150 amu and over a partial pressure range from ntorr to ptorr. The subject analyzer was also prepared for extended testing, in conjunction with two other candidate instruments, in a large molecular beam vacuum facility.
Torney, F. L.↗
Gyroscope test of gravitation: An analysis of the important perturbations
Two perturbations, the earth's quadrupole moment and the earth's revolution around the sun, are discussed. Schiff's proposed gyroscope test of gravitation is analyzed, along with the capability of deciphering each separate contribution to the angular velocity of spin precession.
Oconnell, R. F.↗
Noise from two-dimensional vortices
The fluctuating flow in an idealized model of a turbulent shear layer composed of many discrete vortices is analyzed. Computer solutions reveal irregular motions which are similar in many respects to observed flows in turbulent three-dimensional layers. The model is further simplified to a pair of equal co-rotating vortices and the noise generation is analyzed in terms of equivalent quadrupole oscillations. Results of the analysis in a uniform medium are consistent with Lighthill's results. New results are obtained for the effects of mean velocity gradients, compressibility, temperature inhomogenities, and gradients of the mean Mach number.
Sanders, N. D.↗
Wind tunnel mass spectrometer design study
The sampling probe to measure the free stream gas composition in a hypersonic wind tunnel is described. Using a free expansion of the continuum flow, a series of sampling inlet-pumping stages is evaluated. Mass analysis is carried out with a quadrupole mass spectrometer employing a crossed electron beam, molecular beam ion source, and an off-axis electron multiplier. The spatial distribution of the sampled molecular flux and the pumping requirements are evaluated for varying inlet conditions of gas density and flow velocity. The signal-to-noise ratio of the molecular beam formed by this series of coaxial inlets is also determined. The signal-to-noise ratio of the unscattered flux is sufficiently high that an unambiguous determination of the beam composition and of the free stream gas properties can be made. The magnitude of the detected signal is sufficiently high that measurement of trace constituents two orders of magnitude below the primary beam signal can be made.
Hueser, J. E.↗
V-3 contamination test in the Manned Spacecraft Center's vacuum chamber-A
The V-3 contamination test was designed to measure the degree to which the vacuum facility might be a source of contamination. One test measurement subsystem consisting of a quadrupole residual gas analyzer, a quartz crystal microbalance, and an ion gage is described.
Tashbar, P. W.↗
A Comparison of Quartz Crystal Microbalance Measurements with Mass Spectrometer Determinations
An experimental program was undertaken in which mass accretion rates, as determined by a liquid nitrogen cooled quartz crystal microbalance, were compared with the mass flux rates, as determined by both a cycloidal type and a quadrupole type residual gas analyzer for five simple materials. The data indicate a high degree of correlation between these instruments insofar as the shape of the curves. There are large variations however among the absolute values.
Kruger, R.↗
Lunar mass spectrometer test program
The procedures are described along with results obtained in a test program conducted to demonstrate the performance of a candidate lunar mass spectrometer. The instrument was designed to sample and measure gases believed to exist in the lunar atmosphere at the surface. The subject instrument consists of a cold cathode ion source, a small quadrupole mass analyzer and an off axis electron multiplier ion counting detector. The major program emphasis was placed on demonstrating instrument resolution, sensitivity and S/N ratio over the mass range 0-150 amu and over a partial pressure range from 10 to the minus 9th power to 10 to the minus 13th power torr. Ultrahigh vacuum tests were conducted and the minimum detectable partial pressure for neon, argon, krypton and xenon was successfully determined for the spectrometer using isotopes of these gases. With the exception of neon, the minimum detectable partial pressure is approximately 4 x 10 to the minus 14th power torr for the above gases.
Torney, F. L.↗
Role of gas surface interactions in the reduction of OGO-6 neutral gas particle mass spectrometer data
The gas-surface interaction effects observed by the quadrupole mass spectrometer are described, and the technique developed to account for them in determining ambient neutral densities is summarized. The total ion current and the ion currents for ions with molecular weights 2, 4, 16, 28, and 32 are sampled for 1.125 sec once every 9.216 sec, for 258 sec out of a 368 sec cycle. An equation is given for the number density of any constituent in the ion source region, and source density data are discussed. The mass 28 background gas is considered to be CO rather than N2, and a CO model is developed. A quasi-equilibrium model of the atomic oxygen interactions is constructed, and a set of surface parameters is determined which provides a reasonable fit to the mass 16 and 32 source densities consistent with the predicted ambient atomic oxygen.
Hedin, A. E.↗
The distribution of NO2(plus) in the lower ionosphere
Data on the NO2(+)(46 AMU) were obtained with a rocket-borne quadrupole ion mass spectrometer. The ion 46(+) is most prevalent in the vicinity of 90 km and is always observed in the presence of 48(+), identified as NO(+)-H2O. The observed concentrations of O(+)(16), O2(+)(32), NO2(+)(46), NO(+)-H2O(48), electrons, and the ratio 48(+)/46(+) are tabulated for altitudes from 87.8 to 93.2 km. Reactions governing the distribution of NO2(+) are briefly discussed, and it is felt that photoionization and charge exchange reactions are insufficient to account for the NO2(+) concentration at 90 km.
Aikin, A. C.↗
Noise from two-dimensional vortices.
The fluctuating flow in an idealized model of a turbulent shear layer composed of many discrete vortices is analyzed. Computer solutions reveal irregular motions which are similar in many respects to observed flows in turbulent three-dimensional layers. The model is further simplified to a pair of equal co-rotating vortices and the noise generation is analyzed in terms of equivalent quadrupole oscillations. Results of the analysis in a uniform medium are consistent with Lighthill's results. New results are obtained for the effects of mean velocity gradients, compressibility, temperature inhomogeneities, and gradients of the mean Mach number.
Sanders, N. D.↗
Observations of nonlinear scattering from a plasma column.
Nonlinear interaction effects are considered for signals incident on an unmagnetized cold plasma column, without making the quasi-static approximation. It is found that the nonlinearly generated quadrupole component is only modified slightly and that no multipolar component can give a forward- or back-scattered signal. However, strong nonlinear forward scattering was observed in previous experiments. This spurious result has been traced to the effect of the earth's magnetic field. When this is cancelled, predominantly quadrupolar radiation is observed, in agreement with theory.
Bruce, R. L.↗
Mercury's perihelion advance - Determination by radar.
Measurement of echo delays of radar signals transmitted from earth to Mercury, yielding an accurate value for the advance of the latter's perihelion position. Given that the sun's gravitational quadrupole moment is negligible, the result in terms of the Eddington-Robertson parameters is (2 + 2 gamma-beta)/3 approximately equal to 1.005 plus or minus 0.007, where gamma = beta = 1 in general relativity, and where 0.007 represents the statistical standard error. Inclusion of the probable contribution of systematic errors raises the uncertainty to about 0.02.
Shapiro, I. I.↗
Atomic processes in astrophysics.
Studies of particle excitation processes in the solar corona are reviewed, covering electron affinities, negative ion experiments using two-photon laser and drift tube techniques, geometrical hindrance in molecular ion formation, negative ion-molecule reactions, and negative ions in the ionosphere and astrophysics. Aspects of forbidden atomic transitions are also discussed, including the calculation of transition probabilities, the Fe II problem, and magnetic quadrupole radiation in a relativistic approximation.
Garstang, R. H.↗
On the possible detection of H2 in Titan's atmosphere.
Review of the weak absorption features in Titan's spectrum detected at the wavelengths of the 3-0S(1)H2 quadrupole line and, with less certainty, the S(0) line of the same band. The probable reality of these features is discussed in terms of a statistical analysis of the photometric data, and evidence is presented that they are not scattered from Saturn by the sky or the telescope. Based on the assumption that this absorption arises from H2, implied abundances are estimated, and the implications this has for escape and outgassing rates are discussed.
Trafton, L.↗