Objectif
The main objective of this work was to develop and characterise high flux thermal energy beam sources of reactive atoms of scientific and technological interest. Atom beam sources of atomic hydrogen, oxygen, nitrogen and the halogens have been studied.
Measurements were concentrated on 3 types of source:
a 2.45 GHz microwave extended quarter wave cavity source;
a Slevin type radio frequency source;
a specially developed 2.45 GHz discharge source using a Lisitano coil to achieve the necessary power matching.
Diagnostics based on mass spectrometry and optimal spectroscopy have been used to characterise source performance in terms of measured dissociation fraction, beam density, source operating pressure and input power. The influences of different source cleaning procedures and of gas purity have also been investigated. Considerable effort has also gone into exploring the influence of types of glass or quartz used for discharge tube fabrication and the effect of cooling and extraction geometry.
A number of studies of specific collision processes involving hydrogen atoms, produced from the studied sources, have been carried out.
This project will be directed towards the development and characterisation of RF and microwave beam sources that are capable of producing higly dissociated beams of well defined H, D, O, N and halogen atoms over a wide range of beam density. Mass spectrometric and optical spectrometric techniques will be used to determine dissociation fractions beam profiles and identify metastable components.
Atom beam sources find application (1) in the investigation of fundamental atomic properties and (2) in the preparation and etching of semiconductor surfaces.
Champ scientifique
- natural sciencesphysical scienceselectromagnetism and electronicssemiconductivity
- natural scienceschemical sciencesinorganic chemistryhalogens
- natural sciencesmathematicspure mathematicsgeometry
- natural scienceschemical sciencesanalytical chemistrymass spectrometry
- natural sciencesphysical sciencesopticsspectroscopy
Thème(s)
Data not availableAppel à propositions
Data not availableRégime de financement
CSC - Cost-sharing contractsCoordinateur
BT7 1NN Belfast
Royaume-Uni