Mats Göthe
PhD Thesis
Experimental Physics

Carlsson Gothe M., 1990. Developments of Instrumentation and Data Acquisition Systems for Charged Particle Spectroscopy. High Resolution Studies of Atoms and Small Molecules. Acta Univ. Ups., Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science 292.30 pages. Uppsala. ISBN 9l-554-2648-4.

Abstract

The redesign of a UV photoelectron spectrometer for gas phase photoelectron, Auger electron and ion fragment spectroscopy is described. Outer valence studies have been carried out for several small molecules. The spectrometer has also been adapted and used for Doppler free coincidence studies on ion fragments of diatomic molecules.

Inner valence studies of atoms and molecules using HeII radiation have, up to now been limited by the intense HeI induced background. A new monochromator for HeII has been built which enables a large extension of the useful energy range in UV photoelectron spectroscopy. The focusing properties of the toroidal grating gives no reduction of the intensity of the HeII radiation after monochromatization. High resolution studies have revealed several new molecular states in N₂, O₂ and CO. A high resolution photoelectron spectrum of Xe is presented which exhibits approximately 70 states previously not observed in photoelectron spectra. Valence studies of formaldehyde, acetylene and methane are also presented.

Two data acquisition systems have been developed. The usefulness of Ada in scientific applications and modern software engineering principles are discussed.

A portable distributed run time system for scientific real-time applications written in Ada, has been designed and implemented. The system allows an application to be pre- and/or post paftitioned and to run on a loosely coupled system. The program units that may be distributed are tasks, task objects, packages, procedures, functions and variables. Task objects may be dynamically distributed. The system has a high fault tolerance due to unit redistribution.

Mats Carlsson Göthe, Department of Physics, Uppsala University
@Mats Carlsson Göthe. 1990. Printed in Sweden 1990 by Lindbergs Grafiska, Uppsala.