SEARCH · Search NASA
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.
Hydrogen and inert gas atoms collisional excitation cross sections calculated by multistate impact parameter approximation
Energy transfer between molecules and excited atoms - quenching of excited argon atoms formed by beta radiation from tritium source and low energy electron impact
Parabolic coordinate evaluation of atomic form factor of hydrogen atom for excitation cross section induced by electron collision
Fast electron calculations for atomic hydrogen excited state ionization
Differential cross sections for Coulomb scattering of electrons without atomic excitation from thin aluminum targets for incident energies from 0.1 to 3.0 mev
The results from a semiclassical calculation of the thermal rate coefficient for the radiative association process H(n = 2) + H(n = 1) - H2 + hv are presented (n is the principal quantum number of the separated hydrogen atoms). The relative importance of this reaction in various environments is briefly discussed. Models of the early universe around the epoch of recombination and protostellar winds have been calculated which include the excited atom process. Not surprisingly, it is shown that the excited atom process will not be important in the general interstellar medium, except possibly in environments where the amount of Ly-alpha photon trapping is large. Examples may be the material surrounding quasars, active galactic nuclei, and bright H II regions. The most likely application of this process might be within rapidly evolving systems where a large transient n = 2 population of neutral hydrogen could result in a burst of molecular hydrogen formation.
Coulomb scattering cross section for electrons without atomic excitation and energy of 1 mev incident on thin aluminum foil
Numerical calculation of electron atom excitation and ionization rates
Radiative mean lives and transition probabilities of electronic states in beam foil excited atomic and ionic carbon
Xenon laser effect on interaction between electron gas and excited atoms in plasma
Atom-atom collisional excitation cross sections obtained from ionization cross sections, noting Thomson classical theory
We discuss three techniques which allow the use of tunable lasers for high resolution and picosecond time scale spectroscopy of core-excited atomic levels. These are: anti-Stokes absorption spectroscopy, laser induced emission from metastable levels, and laser designation of selected core-excited levels.
Relative rate constants for energy transfer from excited argon atoms to various organic molecules
Relative population and mean lifetimes of levels in hydrogen and helium atomic beams using foil method of excitation
The charge exchange cross sections for protons and various alkali atoms are calculated using the classical approximation of Gryzinski. It is assumed that the hydrogen atoms resulting from charge exchange exist in all possible excited states. Charge transfer collisions between protons and potassium as well as protons and sodium atoms are studied. The energy range investigated is between 4 and 30 keV. The theoretical calculations of the capture cross section and the cross section for the creation of metastable 2S hydrogen are compared to experimental values. Good quantitative agreement is found for the capture cross section but only qualitative agreement for the metastable cross section. Analysis of the Lyman alpha window in molecular oxygen suggests that measured values of the metastable cross section may be in error. Thick alkali target data are also presented. This allows the determination of the total electron loss cross section. Finally, some work was done with H2(+).
Time dependent matrix elements for multistate impact-parameter calculations for atom-atom inelastic cross sections
Coulomb Born approximation derived for ionization of hydrogen atom by electron collision when atom is in any given initial state
Lithium atom excitation of atomic hydrogen