Physical review. A, General physics · 1977 · 720 citations · 31 references
Natural SciencesPhysicsComputational PhysicsNuclear PhysicsParticle PhysicsAtomic CollisionsAtomic IonizationCollision TheoryHydrogen AtomIonization ProcessesMolecular CollisionsClassical Trajectory CalculationsCollision Cross SectionsCoulomb Collision TheoryCoulomb InteractionIon-atom CollisionsIon-ion CollisionsIonizationIonization Cross Sections
Classical trajectory Monte Carlo calculations were employed to compute charge‑transfer and impact‑ionization cross sections for collisions of fully and partially stripped ions with hydrogen over velocities 2–7×10^8 cm/s, modeling the hydrogen atom and Coulomb forces in three dimensions. The total electron‑loss cross sections vary little with velocity for high charge states, reaching 2×10^−14 cm² for Kr^+36 + H, and the relative importance of impact ionization decreases with increasing charge, with results agreeing reasonably with experimental data for H^+, C^+, N^+, and O^+ + H.
Classical trajectory calculations have been used to predict the charge-transfer and impact-ionization cross sections for collisions of ${A}^{+q}$+H in the velocity range of (2-7) \ifmmode\times\else\texttimes\fi{} ${10}^{8}$ cm/sec. The calculations employ a three-dimensional Monte Carlo approach that uses a classical description of the H atom and the Coulomb forces among all particles to obtain the cross sections. The positive ions studied include fully stripped ${A}^{+q}$, with $q=1\ensuremath{-}8, 10, 14, 18, 26, \mathrm{and} 36$, and partially stripped ${\mathrm{B}}^{+q}$, ${\mathrm{C}}^{+q}$, ${\mathrm{N}}^{+q}$, and ${\mathrm{O}}^{+q}$, with $q\ensuremath{\ge}3$. The total electron-loss cross sections (sum of charge exchange and impact ionization) vary only slightly with velocity for the higher charge states and reach a value of 2 \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}14}$ ${\mathrm{cm}}^{2}$ for ${\mathrm{Kr}}^{+36}$ + H collisions. The importance of impact ionization relative to charge transfer is found to decrease with increasing $q$ in the velocity range studied. Transition probabilities versus impact parameters are presented for the ${\mathrm{H}}^{+}$ + H and ${\mathrm{Ar}}^{+18}$ + H reactions. The calculations are in reasonable agreement with experimentally measured cross sections for the ${\mathrm{H}}^{+}$, ${\mathrm{C}}^{+q}$, ${\mathrm{N}}^{+q}$, and ${\mathrm{O}}^{q+}$+H systems.
31
D. R. Bates, George W. Griffing · Proceedings of the Physical Society Section A · 1953 · 454 citations