Absolute Electron Scattering Cross Sections for the CF2 Radical

Author: Leigh Randall Hargreaves

Hargreaves, Leigh Randall, 2008 Absolute Electron Scattering Cross Sections for the CF2 Radical, Flinders University, School of Chemistry, Physics & Earth Sciences

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Abstract

This thesis describes an experimental study of elastic electron scattering from CF2 radicals, in the intermediate energy regime. Measurements of the absolute differential, integral and momentum transfer cross sections for CF2 are presented. These measurements were performed using a new crossed beam spectrometer, incorporating a supersonic gas source and normalised using a new technique, with both of these features being extensively developed as a major part of this study. The organisation of this thesis is as follows: A brief justification for this research is presented in Chapter 1, together with a review of the spectroscopy and electron collision cross sections which are currently available for the CF2 radical. The crossed beamed apparatus and experimental techniques used to perform the present cross section measurements are then described in detail in Chapter 2, and the theory behind the new normalisation technique is subsequently presented in Chapter 3. Results from the present study are given in Chapter 4. Firstly, differential cross sections measurements for stable molecules are presented, to validate the new normalisation method. Characterisation data for the dissociation dynamics of C2F4 into CF2 radicals are then presented and, finally, differential cross section measurements for the CF2 radical are explored. Where possible, the measured data for CF2 are compared against results from theoretical calculations and the implications of the present results are discussed. The major findings of this research are then summarised in Chapter 5, and directions for future research using the present apparatus are also discussed here. Finally, some additional findings from this research and calibration data for the current apparatus are given in the appendices.

Keywords: electron scattering,cross sections,radicals,SSRDM,CF2
Subject: Physics thesis

Thesis type: Doctor of Philosophy
Completed: 2008
School: School of Chemical and Physical Sciences
Supervisor: Ass. Prof. Michael Brunger