Cross sections and product kinetic energy analysis of H2O+ - H2O collisions at suprathermal energies

Technical Report · Tue Jan 01 04:00:00 EST 1991

OSTI ID:5539584

Lishawa, C R; Dressler, R A; Gardner, J A; Salter, R H; Murad, E

An exact formulation of the impulse approach (IA), or quantum-mechanical spectator model, is applied to atom-diatom collisions. Results are compared with previous work on the IA, which has always involved the peaking approximation (PA). The PA is seen to overestimate (underestimate) differential cross sections for processes involving projectile atom energy loss (gain). The internal consistency of the IA is explored by subjecting it to semidetailed balancing. For small scattering angles the IA is seen to be an inadequate theory, probably due to the neglect of double-and higher collision terms in the multiple-collision expansion of the three-body T matrix. For large scattering angles, where the IA does appear to describe the scattering process accurately, the exact calculation is shown to give the same results as when only the energy-conserving on-the-energy-shell two-body processes are considered. An accurate approximation method is also developed for rapid computation of inelastic differential cross sections.

• Research Organization: Phillips Lab., Kirtland AFB, NM (United States)
• OSTI ID: 5539584
• Report Number(s): AD-A-232004/2/XAB; PL-TR--91-2018
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ACCURACY
ATOM COLLISIONS
ATOM-MOLECULE COLLISIONS
ATOMS
COLLISIONS
COMPARATIVE EVALUATIONS
CROSS SECTIONS
DIFFERENTIAL CROSS SECTIONS
ENERGY
IMPULSE APPROXIMATION
KINETIC ENERGY
LOSSES
MATHEMATICAL MODELS
MATRICES
MECHANICS
MOLECULE COLLISIONS
PROJECTILES
PULSES
QUANTUM MECHANICS
S MATRIX
SCATTERING