| Summary: | This thesis describes a series of experiments undertaken to collect Angle Resolved Mass Spectra (ARMS) in order to investigate the scattering of ions during collisional activation. In particular, data were obtained to see if the angle resolved mass spectra of the scattered ions could be explained by assuming that the scattering angle θ was directly related to the energy gained by the ions during collisional activation. Initially data were obtained on a slightly modified commercially available mass spectrometer using the z-deflection method. The inherently poor angular resolution of this method limited the scope of these experiments to an investigation of the effect of experimental variables on ARMS data. To overcome the problems of the z-deflection method a swinging source was designed and fitted to the mass spectrometer. The major advantages of this source were that θ was selected mechanically and that the pre- and post-collision angular resolutions of the experiments could be varied, but were independent of the masses of the ions. Using the source, data similar to those published by other groups were obtained. Interpreting these data, however, was difficult because fragment ion abundances contained contributions from decompositions occurring outside the collision chamber. A modification was made to the source which enabled these ions to be excluded from the data and the effect of this modification on the ARMS spectra obtained is discussed.
|
|---|
