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Electron-Cluster Interactions: Excitation Of Neutral Fragments In Rare Gases And Simple Molecules., Charles Patrick Malone
Electron-Cluster Interactions: Excitation Of Neutral Fragments In Rare Gases And Simple Molecules., Charles Patrick Malone
Electronic Theses and Dissertations
The presented work on electron-cluster interactions utilizes mass and translational spectroscopic techniques that have traditionally been applied to atomic and molecular targets.
Experimental Study And Theoretical Modelling Of Ultrasonic Wave Propagation In Resistance Spot Welds., Andriy M. Chertov
Experimental Study And Theoretical Modelling Of Ultrasonic Wave Propagation In Resistance Spot Welds., Andriy M. Chertov
Electronic Theses and Dissertations
The theoretical and experimental study of resistance spot weld quality has a long history. Since the invention of the method manufacturers are concerned about the means of quality assurance of the joints. One of the most promising current techniques of quality inspection is the real time ultrasonic nondestructive evaluation. In such a system the acoustic signals are sent through the spot weld during welding and then analyzed to predict the size of the future joint. In spite of its purely industrial application and seemingly easy setup the problem involves several complicated mechanisms to be described using a physical-mathematical approach. This …
Ultrasonic Propagation Across A Thin Layer Between Two Bulk Media: Theory, Computer Simulation And Experiment., Jeffrey. Sadler
Ultrasonic Propagation Across A Thin Layer Between Two Bulk Media: Theory, Computer Simulation And Experiment., Jeffrey. Sadler
Electronic Theses and Dissertations
This thesis describes the changes in the reflected and transmitted acoustic waves due to the addition of a thin layer (thickness much less than an acoustic wavelength) between two half-spaces of material. The restriction of the thin layer allows one to combine perturbation methods with the standard fully bonded boundary conditions at each interface and derive a set of equations where one no longer is concerned with the acoustic waves internal to the thin layer. This approach allows one to further examine the cases of a nonlinear thin layer, an anisotropic thin layer, and a thin layer with combined anisotropy …
Electron Collision Studies Of Cesium Using A Magneto-Optical Trap., John Alexander. Macaskill
Electron Collision Studies Of Cesium Using A Magneto-Optical Trap., John Alexander. Macaskill
Electronic Theses and Dissertations
Experiments involving a magneto-optical trap (MOT) as the target in electron impact cross section studies were carried out. The use of a MOT allows the kinematic properties of the target atoms, and their electronic states, to be controlled via operating parameters of the MOT's lasers. A MOT is capable of saturating the excited state of a gaseous target of atoms and provides a unique opportunity to measure exotic collision processes. Measurements use a trap-loss technique to relate the loss rate of atoms from the trap due to electron interactions to a collision cross section. Total scattering cross section measurements are …
Electron Impact Excitation Studies Of Unstable Atomic Species., Ady Kamel. Abdellatif
Electron Impact Excitation Studies Of Unstable Atomic Species., Ady Kamel. Abdellatif
Electronic Theses and Dissertations
The polarization of Balmer-alpha radiation excited in collisions of electrons with atomic hydrogen is presented for an electron energy range from threshold to 1000 eV. Measurements are in good agreement with calculations carried out using either convergent-close-coupling or R-matrix with pseudo-states approaches. Cascade is demonstrated to have a significant effect. Balmer-alpha excitation function data are also presented. A previous measurement of the polarization of Balmer-alpha following dissociative excitation of H2 by electrons is confirmed and extended. The electron impact excitation spectrum of atomic and molecular nitrogen in the VUV range (800 A--1800 A) is presented. The excitation functions of the …