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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.

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At least 181 records · Page 10
All sourcesNASA NTRSDOE OSTI
NASA NTRS1975

A study of the interaction of neutral and charged particles

Preliminary experimental data on the number of charged neutral nuclear-active particles were obtained at 200 BeV. The ratio of the number of charged particles to the number of neutral particles was 2.1 + or - 0.3. Nuclear cascade curves in iron and distributions over the portions of energy transferred to neutral pions in lead were obtained for avalanches generated by charged and neutral particles. The characteristics of interactions of the charged neutral particles at the existing experimental errors showed no difference.

Kim, V. M.↗
NASA NTRS1974

The diffusive idealization of charged particle transport in random magnetic fields

The transport of charged particles diffusing in a random magnetic field parallel to a relatively large guiding field is presented. The same coefficient of diffusion is obtained by three methods. Two corrections must be added to the expression in which the diffusive flux is proportional to the gradient of the density. Explicit expressions are given for a characteristic time and a characteristic length which describe the corrections. The well known divergence of the coefficient of diffusion, which is implied by the quasilinear analysis of pitch angle scattering, does not occur if the scattering rate is finite at 90 deg pitch angle. This effect is illustrated by formulas which give the coefficient of diffusion when the quasilinear expression is perturbed by a variable amount of isotropic scattering.

Earl, J. A.↗
NASA NTRS1975

Study of fluid flow by charged particles

Analytical and experimental effort explores possibility of using charged particles as diagnostic tool in study of fluid flows. Test program involved right circular cylinder and airfoil located in large wind tunnel; ions were injected into flow and resulting currents at surfaces were monitored.

Deluca, M.↗
NASA NTRS1980

Encounters with Jupiter - The Low Energy Charged Particle results of Voyager

Results of the Low Energy Charged Particle (LECP) experiments on board the Voyager spacecraft, designed to measure the fluxes and compositions of ions of energies 28 keV or greater and electrons of energies 15 keV or greater, during Jupiter encounter are presented. Observations of intense particle bursts coming from Jupiter several weeks before Jovian magnetosphere entry, magnetopause crossings, a hot corotating outer magnetospheric plasma, decreases in particle fluxes at the orbits of the Galilean satellites 10-hr particle flux periodicities and a magnetospheric wind are discussed. A new model of the Jovian magnetosphere based on the Voyager results is presented, and areas of continuing LECP Jovian data analysis are indicated.

Carbary, J. F.↗
NASA NTRS1981

Analytical description of charged particle transport along arbitrary guiding field configurations

Aspects of charged particle transport theory have been studied by Earl (1973, 1974, 1976) in a number of investigations. The investigations were conducted under the assumption that particles propagate along a DC guiding field with negligible perpendicular transport and that pitch-angle scattering by random fields can be described by the Fokker-Planck formalism. The present study provides a generalized and simplified treatment of focused transport. The first step is taken with respect to a perturbation analysis by which the Boltzmann equation is solved in terms of successively improved approximations to its exact solution. The first approximation is the sum of isotropic pseudodiffusive and anisotropic supercoherent components whose coefficients must satisfy two coupled partial differential equations. The normalization constant K and the pseudodiffusive velocity, which appear in the first-order transport equations, are given by simple integrals over the pitch angle.

Earl, J. A.↗
NASA NTRS1973

Production of carbon monoxide by charged particle deposition.

Recent studies of electron energy deposition in CO2 and CO based upon a large set of electron impact cross sections are utilized to estimate the telluric CO directly produced by various charged-particle deposition mechanisms. The mechanisms considered are (1) lightning, (2) cloud coronal discharges, (3) background radioactivity, (4) natural electrostatic discharges, (5) photoelectrons in the ionosphere, (6) auroral electrons, (7) auroral protons, (8) cosmic rays, and (9) solar wind. 'Ball park' estimates of the global CO production by each of these mechanisms are given. Apart from mechanisms 1, 2, and 5, all CO production mechanisms are estimated to be small compared to artificial sources. If, as appears to be the case, the hot oxygen atoms and ions and other atomic species immediately produced by these three charged-particle deposition mechanisms react rapidly with CO2 to produce CO, these mechanisms can readily lead to CO production levels in the multimegaton-per-year range.

Green, A. E. S.↗
NASA NTRS1995

CMOS Charged Particle Spectrometers

Integrated circuits manufactured in CMOS technology, have been developed as diffusion-based charged particle spectrometers for space applications. A four-chip spectrometer designed to count protons and heavier ions was flown on the Clementine spacecraft, and the spectrometer proton response is compared to GOES-6 proton data for the 21 Feb. 1994 solar proton event.

charged↗
NASA NTRS1983

Scintillator-fiber charged-particle track-imaging detector

A scintillator-fiber charged-particle track-imaging detector has been developed using a bundle of square cross-section plastic scintillator fiber optics, proximity focused onto an image intensified Charge Injection Device (CID) camera. Detector to beams of 15 MeV protons and relativistic Neon, Manganese, and Gold nuclei have been exposed and images of their tracks are obtained. This paper presents details of the detector technique, properties of the tracks obtained, and range measurements of 15 MeV protons stopping in the fiber bundle.

Binns, W. R.↗
NASA NTRS1976

Analysis of LEAM experiment response to charged particles

The objectives of the Lunar Ejecta and Meteorites Experiment (LEAM) were to measure the long-term variations in cosmic dust influx rates and the extent and nature of the lunar ejecta. While analyzing these characteristics in the data, it was discovered that a majority of the events could not be associated with hypervelocity particle impacts of the type usually identified with cosmic dust, but could only be correlated with the lunar surface and local sun angle. The possibility that charged particles could be incident on the sensors led to an analysis of the electronics to determine if such signals could cause the large pulse height analysis (PHA) signals. A qualitative analysis of the PHA circuit showed that an alternative mode of operation existed if the input signal were composed of pulses with pulse durations very long compared to the durations for which it was designed. This alternative mode would give large PHA outputs even though the actual input amplitudes were small. This revelation led to the examination of the sensor and its response to charged particles to determine the type of signals that could be expected.

Perkins, D.↗