Pulsed power electron and ion beams diagnostics based on simultaneous detection of acoustic longitudinal and flexural waves

摘要

A method and technique for measuring the pulsed power electron and ion beam energy density (W in J/m/sup 2/) absorbed by a target as well as the main elastic constants of material have been proposed and realized. The method developed is based on the authors' laser-interferometric and theoretical investigations of the space-time characteristics and amplitudes of thermoacoustic waves excited by pulsed power electron beams in various solids: metals; alloys; semiconductors; amorphous and crystalline dielectrics; and composites. Experimental conditions under which compression-expansion pulse of the longitudinal wave and flexural oscillations of a sample can be observed simultaneously, have been found. As the experiments have shown, the amplitude of thermoelastic flexural wave as well as the amplitude of longitudinal pulse is proportional to W. The authors reconstruct the profile of beam dose absorbed by material and determine W using available standard samples with known elastic constants and Gruneisen's parameter and the interferometry data on longitudinal and flexural thermoacoustic waves.