Free-Position Annihilation Mean Life in a Diatomic and Rare Gases in Liquid and Solid States
Free positron annihilation mean lifetimes in rare and diatomic gases in liquid and solid states
LIFETIME↗
SEARCH · Search NASA
Results for “Positrons”
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.
Charge ratio of cosmic-ray electrons
Positron-to-electron ratio of cosmic electrons from meson decay
ELECTRON↗
An investigation of the intensities and charge composition of low energy electrons at balloon altitudes
Detector for measuring positron-to-electron ratio at balloon altitudes as function of electron energy
POSITRON↗
Charge ratio of cosmic-ray electrons
Excess of positrons to electrons from high energy cosmic ray secondaries
POSITRON↗
Alfvenic Solitons in Ultrarelativistic Electron-Position Plasmas
In electron-positron plasmas some of the plasma modes are decoupled due to the equal charge-to-mass ratio of both species. We derive the dispersion law for a low-frequency, generalized X-mode, which exists at all angles of propagation with respect to the static magnetic field.
Electron-positron plasmas Pulsars Nonlinear Modes↗
Opacity of the universe to high-energy photons.
High energy photon absorption in space due to electron-positron pair production in photon-photon collision
COSMOLOGY↗
Supernovae explosions induced by pair production instability
Supernovae explosions induced by electron-positron pair production instability
Fraley, G. S.↗
Dominant nonadiabatic contribution to the long-range electron-atom interaction.
Low energy electron /or positron/ scattering by spherically symmetric atoms, discussing long range interactions
Hahn, Y.↗
Effect of the anomalous magnetic moment of the electron on spontaneous pair production in a strong magnetic field.
Electron anomalous magnetic moment effect on spontaneous electron-positron pair production in strong magnetic field, noting relationship to expanding universe models
Oconnell, R. F.↗
Supernovae explosions induced by pair- production instability.
Stars with core greater than 30 solar masses become unstable due to electron-positron pair production at 1.5-2 billion K leading to supernova
Fraley, G. S.↗
On the transient nature of the galactic halo.
Galactic halo chronology determination by positron component flux measurement in primary cosmic rays
Brunstein, K.↗
Vibro-rotational excitations of H2/+/ by e/+/ impact - A semi-classical approach
Semiclassical approach to vibrorotational excitations of H2/+/ by positron impact
Faisal, F. H. M.↗
Charge composition and energy spectrum of primary cosmic-ray electrons
Flux, energy spectrum and charge composition of primary cosmic ray electrons measured, determining energy spectrum of primary positrons above 220 Mev
Fanselow, J. L.↗
Na22, Al26, Th and U in Apollo 11 lunar samples
Apollo 11 lunar samples composition for Na 22, Al 26, Th and U, investigating positron activities
Herman, G. F.↗
Cosmic gamma rays
Book on cosmic gamma rays covering secondary particle decay, electron-positron annihilation, proton-antiproton interactions, galactic radiation and cosmology
Stecker, F. W.↗
Cyclotron production of I-123: An evaluation of the nuclear reactions which produce this isotope
The reactions studied which produce I-123 directly were Sb-121(He-4,2n) I-123, Sb-121(He-3,n) I-123, Te-122(d,n) I-123, Te-122(He-4,p2n) I-123, Te-122(He-3,pn) I-123, and Te-123(He-3,p2n) I-123. Reactions which produce I-123 indirectly through the positron decay of 2.1-hour Xe-123 were Te-122(He-4,3n) Xe-123, Te-122(He-3,2n) Xe-123 and Te-123(He-3,3n) Xe-123. Use of the gas flow I-123 cyclotron target assembly is recommended for the production of I-123 with radiochemical purity greater than 99.995%.
Sodd, V. J.↗
Primary and secondary particle contributions to the depth dose distribution in a phantom shielded from solar flare and Van Allen protons
Calculations have been made using the nucleon-meson transport code NMTC to estimate the absorbed dose and dose equivalent distributions in astronauts inside space vehicles bombarded by solar flare and Van Allen protons. A spherical shell shield of specific radius and thickness with a 30-cm-diam. tissue ball at the geometric center was used to simulate the spacecraft-astronaut configuration. The absorbed dose and the dose equivalent from primary protons, secondary protons, heavy nuclei, charged pions, muons, photons, and positrons and electrons are given as a function of depth in the tissue phantom. Results are given for solar flare protons with a characteristic rigidity of 100 MV and for Van Allen protons in a 240-nautical-mile circular orbit at 30 degree inclination angle incident on both 20-g/sq cm-thick aluminum and polyethylene spherical shell shields.
Santoro, R. T.↗
Medium-to-medium transition radiation and the detection of ultrarelativistic charged particles
The use of X-ray transition radiation to distinguish between protons and positrons of equal rigidity was investigated. A formula for the transition radiation spectrum from a medium-to-medium boundary was derived. The formation zone effect was found to limit the detection of transition radiation from ultrarelativistic particles. Curves showing the results of the spectrum calculations are presented.
Robbins, D. E.↗