Other men's flowers: Classical treatment of collisions; Massey's adiabatic criterion and ionization in flames; ion-molecule reactions; bound-free and free-free transition of electrons in ambient atomic hydrogen☆

摘要: Abstract The article is concerned with four different topics. 1. Classical collision theory . Interest in the classical treatment of phenomena was twice aroused by study stopping power, firstly before wave mechanics developed and secondly 1959 Gryzinski. original interest waned because quantum (and only it) could principal provide exact results. However a clasical often useful indeed may, as case electron capture from heavy atoms fast light nuclei, give better results than can at present be obtained attempting to find appropriate solution Schrodinger's equation. In connection electron-atom collisions it argued that non-symmetrical version practice superior symmetrized reason for this proposed. It necessary make allowance mean free path projectile while within target system being general less linear dimension system. impact ionization cross sections formula derived are least close accord laboratory data those Born (exchange) approximation. 2. Massey's adiabatic criterion flames Reliance may placed on between atomic systems unlikely cause an electronic transition if certain parameter λ M large compared unity. probability due dipole interaction, one quadrupole interaction Landau-Zener functions all fall off around same rate increased. If appears violated physical interpretation adopted cannot correct. Contrary what might initially supposed no way anomalous section sodium burnt flame gas mixtures 2000 K 3000 should high 2.5 × 10 −12 cm 2 3. Ion-molecule reactions Exothermic ion-molecule play vital part ion-chemistry upper atmospheres Earth planets interstellar clouds. For these other reasons they have been subject many experimental investigations. Apart Langevin coefficient collisions, has contributed little. Far enabling coefficients predicted does not even means systemizing data. state method enables range main features measured understood terms. absence activated energy E (act) must taken into account properly: suffice simply let vanish standard coefficient. Moreover attention paid possibility transmission very small; effect peculiar nebular nature complex; Teller crossings potential hyper-surfaces transitions. 4. Absorption H - + e atmosphere Calculations absorption combination photo-detachment hydrogen negative ions free-free transitions electrons carried out over past 40 years still continuing. object whether explanation provided variation wavelength solar current accurate quantal order utilized obtain information depths atmosphere. There were four, partly overlapping, stages work: increase 3 70 number variational parameters Hylleraas type function representing bound state; change length velocity formulation matrix element weigh more heavily which best determined application Rayleigh-Ritz principle; refinement function; addition tail having correct asymptotic form Hylleraas-type state. Progress calculation contribution proceeded problem difficult scattering rapidly become sophisticated.