Michael E. Gersh

Translational Energy Dependence of the Reaction Cross Section for K+CH3I→ KI+CH3 from 0.1 to 1 eV (c.m.)

A molecular beam study of the reaction K+CH3I→ KI+CH3 over an extended range of collision energy is described. A thermal K beam is crossed with a seeded supersonic nozzle beam of CH3I. The excitation function (energy dependence of the reaction cross section) for this reaction was measured from 0.1 to 1 eV (c.m.). The total flux of the KI reaction product was determined by integration over the laboratory spherical polar coordinates (Θ,  Φ) of the in‐plane and out‐of‐plane angular distributions of KI measured by a two‐filament differential surface ionization detector mounted on a goniometer. By seeding the CH3I with a variety of lighter gases, its velocity could be changed from δ ≈ 530–2330  m/sec. The average center of mass collision energy, Ē, was thereby varied from 0.1 to 1 eV. The densities of both beams were monitored during the scattering experiments, so that relative cross sections vs Ē were obtained with a precision of ≈ ± 10%. The supersonic CH3I beam speed distributions were quite narrow (FWHM ≈ ...

Versatile high temperature flow reactor for kinetic and spectroscopic studies

A high temperature flow reactor has been constructed to perform kinetic and spectroscopic studies on species at temperatures between 300 and 1500 K. The species in the flow reactor may be detected or studied using: laser‐induced fluorescence, resonance fluorescence, infrared absorption, ultraviolet absorption, chemiluminescence, or molecular beam mass spectrometry. The features of the apparatus are described in detail, and the initial spectroscopic and kinetic studies are discussed.

Measurement of the vibrational band strength of 11BF using a tunable diode laser

The infrared band strength for the fundamental vibrational mode of 11BF is measured by line absorption of the P(11) transition at 1343.5 cm−1 using a tunable diode laser and multipass absorption cell coupled to a discharge flow apparatus. The BF number density is simultaneously determined by ultraviolet absorption at the bandhead of the A 1Π←X 1Σ transition at 196 nm. The resulting value for the band strength is 650±200 cm−2 (STP atm)−1, which is in good agreement with existing theoretical calculations.

Calculated total elastic scattering cross sections for H(IS) at collision energies below 1 eV

Abstract Exact computations of the elastic scattering cross sections for atomic hydrogen, based on the best local 1 σ + g 3 σ + u potentials, provide an accurate, essentially ab initio prediction of the glory and resonance behavior to be expected in H(IS) beam scatterring experiments.