Measurements of the cusp electron peak in coincidence with target recoil ions and in coincidence with LMM Auger electrons produced in ionizing collisions for the 3 MeV Cℓ + Ar collision system

A new spectrometer has been designed and built for use with an existing multi - spectrometer apparatus. The new spectrometer detects electrons emitted at 0° relative to the incident beam direction. It is a 30° parallel plate electrostatic spectrometer which uses a channel electron multiplier for electron detection. This forward parallel plate analyzer is added to a multi - spectrometer apparatus that can detect electrons ejected at 0°, 180°, and over an angular range of 45° to 135° relative to the incident beam direction. The multi - spectrometer can also detect recoil ions. A charge state analyzer located after the detector allows for the exit charge state to be determined. The new detector has been tested through multiple tests and a computer simulation program. Projectile electron loss to the continuum in atomic collisions is experimentally analyzed in this thesis. The energy distribution of cusp electrons emitted in the forward direction into a 1/2 angle of 4.4° are measured in coincidence with recoil ion charge states. C⁺ ions with an energy of 3 MeV are used in collisions with an argon gas target. The electron energy range scanned with the forward analyzer is from 86 eV to 227 eV. Doubly differential electron loss cross sections are obtained from the data. The data indicate that the projectile electron - target electron interaction produces a significant fraction of the cusp electrons, which have < 1 eV energy in the projectile frame. For this interaction target ionization is a first order process and the target recoil ion charge state distribution is shifted towards higher charge states. A feasibility study is also conducted of a coincidence experiment between projectile electrons ejected into the forward direction and target Auger electrons emitted into the range of 45° to 135°. This thesis shows that such measurements are possible, even though the cross section for the process that is investigated is very low.