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Sims, J. S.

Publications and source records attributed to Sims, J. S..

8 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1974

The lower ionosphere of Venus

Galactic cosmic ray bombardment provides a permanent background ionosphere in planetary atmospheres. A transport technique is used to compute the cosmic ray ionization rate profile in a model of the Venusian atmosphere at altitudes between 55 and 100 km. These ionization rates are then applied to a model of ion chemistry to predict equilibrium electron and ion density profiles. Ionization rates for typical solar flare proton events are available from earlier calculations and have been included.

Dubach, J.↗
NASA NTRS1974

Three-body Coulomb systems using generalized angular-momentum S states

An expansion of the three-body Coulomb potential in generalized angular-momentum eigenfunctions developed earlier by one of the authors is used to compute energy eigenvalues and eigenfunctions of bound S states of three-body Coulomb systems. The results for He, H(-), e(-)e(+)e(-), and pmu(-)p are compared with the results of other computational approaches.

Whitten, R. C.↗
NASA NTRS1973

A model of carbon compounds in the stratosphere and mesosphere.

A photochemical model with vertical transport is employed to compute profiles of CO, CH4, CH3, CH2, CHO, CH2O, CH3O, CH3O2, and CH4O2 from 10- to 90-km altitude. The upper boundary condition is taken as diffusive equilibrium at 120 km, and the lower boundary condition as chemical equilibrium or a flux condition at 10 km. The results are in reasonable agreement with observations and with the results of other model studies.

Whitten, R. C.↗
NASA NTRS1973

The photolytic stability of the Martian atmosphere.

Several recent suggestions for stabilizing the Martian atmosphere against photolysis have proved untenable. However, downward convective transport as well as a low altitude (0-35 km) aerosol, which catalyzes two-body molecular recombination reactions, can bring about such stability. The 'effective' convection velocity and 'average' two-body reaction rate coefficients required by observed abundances are evaluated. The computed profiles of CO and O at high altitude are shown to agree well with observations.

Whitten, R. C.↗
NASA NTRS1971

One-center r sub ij integrals over Slater-type orbitals.

Expressions are derived for the integrals which arise in calculations of atomic wavefunctions of four or more electrons, using the method of explicit introduction of interelectronic distances into a configuration interaction wavefunction (subject to the restriction of at most one interelectronic distance per configuration). The approach followed in the derivations is similar to one followed by OEhrn and Nordling for three electron integrals; however, in extending the OEhrn and Nordling scheme to four electrons for a basis of s, p, and d Slater-type orbitals, numerical snags are encountered which have been obviated by a Euler transformation on certain of the auxiliary integrals.

Sims, J. S.↗