Experimental measurements on angular distribution of ions and ion-energy spectra from planar slab targets of Al, Ti and binary targets of Al, Ti with different stoichiometries are reported. The plasma was produced by a 125 mJ, 5 ns, 1.06 µm Nd:YAG laser, incident on a planar target at a fixed angle of −45°. The laser was focused on an ablation area of about 0.3 mm2 at a laser intensity of about 1010 W cm−2. The characteristics of the ions were obtained using a retarding-potential analyser and a quartz crystal. Results on time-of-flight spectra, ion fractions, average ionization, angular distributions of particles and their kinetic energy are presented. Full width at half maximum of the angular distributions was obtained and the results are discussed. Measurements on total integrated energy per particle are also reported. They show evidence of energy transfer from light to heavy particles in agreement with the theoretical simulation results of earlier workers. Ion acceleration due to an in-built electrostatic potential is discussed in detail and its effect was found to be marginal.

The plane-stress equations of the theory of elasticity are solved to predict the propagation characteristics of flexural and pseudo-Rayleigh modes of infinitely tall ridge guides for frequencies lower than the lowest thickness-shear frequency of thin plates. The parabolic dispersion characteristic of the former mode shows appreciable departure from the hitherto published results in the above limiting case. The large discrepancy is due to the incompatibility of the flexural type of motion in the ridge and the only Rayleigh type of disturbance that the adjoining free substrate can sustain. This causes undesirable radiation of the surface wave energy into the bulk of the substrate and is responsible for cutoff frequencies obtained by several authors. The consequent implication for the useful operational range of such waveguides is discussed. The nondispersive velocity of the latter mode at dc is found to be 1.5% lower than a microwave network result.

A perturbation formulation of the equations of linear piezoelectricity is obtained using a Green’s function approach. Although the resulting equation for the first perturbation of the eigenvalue strictly holds for real perturbations of real eigenvalues only, it is formally extended to the case of purely imaginary perturbations of real eigenvalues. The extended equation is applied in the calculation of the attenuation of surface waves due to the finite electrical conductivity of thin metal films plated on the surface and air loading. The influence of the viscosity of the air is included in the air-loading analysis, and the calculated attenuation increases accordingly. Since the metal films are thin compared with a wavelength, an approximate thin-plate conductivity equation is employed in the determination of the attenuation due to the electrical conductivity of the films. The resulting attenuation is obtained over a very large range of values of sheet conductivity. This is accomplished by using the equation for the first perturbation of the eigenvalue iteratively to determine the solution and attendant attenuation to any desired degree of accuracy. The phase velocity dispersion curve due to the mechanical effect of a thin film plated on a substrate is determined for relatively large wavelengths by employing the perturbation equation iteratively, and excellent agreement is obtained with the results of other more direct approaches. The calculations have been performed for an aluminum film on either ST-cut quartz or Y-Z lithium niobate.

Charge resolved average integrated kinetic energy of ions from plasmas produced from, monoatomic targets of copper and tungsten as well as binary targets of copper and tungsten, with two different stoichiometric compositions, have been obtained using 130 mJ-5 ns Nd:YAG laser pulse, at a focal intensity of about 8 x 10 9 W/cm 2. It is concluded that ionacceleration due to built-in electrostatic potential is not significant and the kinetic energy spectra are determined by the recombination during the plasma expansion. On the basis of the numerical results obtained from Monte-Carlo simulation, a significant energy-transfer from the lighter to the heavier ions seems reasonable in the case of binary targets.

A system of approximate surface wave equations and edge conditions in one scalar variable is derived from Hamilton’s principle for linear piezoelectric media by assuming suitable depth behavior and integrating with respect to depth. The assumed behavior with depth is determined from the known surface-wave solutions of the three-dimensional equations for both the plated and unplated substrate. The influence of the inertia, stiffness, and electrical shorting of the film is included in the analysis. The approximate equations are expressed in terms of the known fundamental material constants and no measurement of model parameters is required. Bulk-wave scattering is not considered. The approximate equations, which admit of a transmission-line representation, are applied in the analysis of surface-wave reflection by both uniformly and nonuniformly spaced arrays of reflecting strips plated on various substrates. Among other things, the calculated reflection curves indicate a slight asymmetry for heavier film materials on account of the dispersion caused by the strips. Although this effect has been observed experimentally, it has not been reproduced by other analytical models.