Open Access. Powered by Scholars. Published by Universities.®

Physics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 4 of 4

Full-Text Articles in Physics

Explosion Of A Liquid Film In Contact With A Pulse-Heated Solid Surface Detected By The Probe-Beam Deflection Method, P.T. Leung, Andrew C. Tam, Nhan Do, Leander Klees, Wing P. Leung Dec 1992

Explosion Of A Liquid Film In Contact With A Pulse-Heated Solid Surface Detected By The Probe-Beam Deflection Method, P.T. Leung, Andrew C. Tam, Nhan Do, Leander Klees, Wing P. Leung

Physics Faculty Publications and Presentations

The threshold for explosive vaporization of a liquid layer on an opaque solid surface heated by an ultraviolet excimer pulsed laser is studied by a photoacoustic probe-beam deflection method. The probe beam traverses the liquid in the vicinity of the laser-heated liquid-solid interface. Below the explosion threshold, photoacoustic generation in the solid occurs only through a thermoelastic mechanism, which results mainly in shear waves that do not couple well into the liquid. Above the explosion threshold, photoacoustic pulses in the solid are also produced by explosive recoil, hence producing longitudinal pulses in the solid that couple well into the liquid …


A Technique For The Evaluation Of Double Excitation Of Atoms By Fast Protons And Antiprotons, Jack C. Straton, James H. Mcguire, Zheng Chen Nov 1992

A Technique For The Evaluation Of Double Excitation Of Atoms By Fast Protons And Antiprotons, Jack C. Straton, James H. Mcguire, Zheng Chen

Physics Faculty Publications and Presentations

A technique for evaluating cross sections for two-electron excitation in collisions of atoms with fast particles of charge ZP is presented. The atomic wave function is approximated by a sum of pair products of one-electron wave functions, with the coefficients chosen by diagonalizing the fully correlated twoelectron Hamiltonian. Thus spatial correlation is included in both the asymptotic and scattering regions by using these configuration-interaction (Cl) wave functions for initial, intermediate, and final states. Use of CI wave function also allows the first-order contributions to be expressed in closed, analytical form. Both the energy-conserving and energy-nonconserving parts of the second-order amplitude …


Transmission Studies Of Explosive Vaporization Of A Transparent Liquid Film On An Opaque Solid Surface Induced By Excimer-Laser-Pulsed Irradiation, P.T. Leung, Nhan Do, Leander Klees, Wing P. Leung, Frank Tong May 1992

Transmission Studies Of Explosive Vaporization Of A Transparent Liquid Film On An Opaque Solid Surface Induced By Excimer-Laser-Pulsed Irradiation, P.T. Leung, Nhan Do, Leander Klees, Wing P. Leung, Frank Tong

Physics Faculty Publications and Presentations

Examines the dynamics of the explosion of a liquid film by an ultraviolet excimer pulsed laser studied experimentally on top of an amorphous silicon film deposited on fused quartz. Background on thermal physics of superheated pure or mixed liquids; Techniques for surface temperature measurement; Experimental of probe laser and pulsed excimer laser.


Diffraction Of Light By A Focused Ultrasonic Wave, J. Huang, Joel Alan Nissen, Erik Bodegom Jan 1992

Diffraction Of Light By A Focused Ultrasonic Wave, J. Huang, Joel Alan Nissen, Erik Bodegom

Physics Faculty Publications and Presentations

The measurement of the acoustic pressure of a planar ultrasonic wave by light diffraction is well established. The ability to do similar measurements in the case of spherical waves has been doubted. However, we show that the range of validity can be extended to the focal region of a spherical concave piezoelectric transducer. Light is passed through the focal plane of a spherical concave transducer and is diffracted as a result of the variation in the index of refraction. The peak pressure can be calculated from the diffraction intensity by making the following simplification. We assume that in the focal …