부산대학교 도서관

A photocurrent can be produced by direct illumination of a dielectric liquid with photons having energies in the vacuum ultraviolet (VUV). The kinetic energy initially imparted to an electron by absorption of a photon is subsequently dissipated through random collisions with molecules in the liquid. With the parent cation at the origin, the distance, r, traveled by the electron in coming into thermodynamic equilibrium with the liquid is called the thermalization range. Electron energy thermalization range distribution functions were determined for electrons created by photoionization of cyclohexane, 2,2-dimethylbutane, tetramethylsilane, and two polydimethylsiloxane oils. Except for cyclohexane, the function [r²/2(B[sub 3])[sup 3]exp(-r/B[sub 3]), where B[sub 3] is an energy-dependent range parameter, gave the best agreement between the calculated and experimental photocurrents at all photon energies considered. Using a Monte Carlo simulation (Goulet type) to represent the slowing down of the electrons after their injection into the liquid, it was found that four to ten collisions along the thermalization path were sufficient to generate this range distribution function. Electrons can also be injected into these liquids by UV illumination of a photocathode. By taking into account electron scattering back to the image charge in the photocathode, it was possible to use the Monte Carlo simulation to demonstrate the consistency between the range distribution function for electron injection by UV exposure of the photocathode and the range distribution function for electron injection by direct VUV illumination of the bulk liquid. [ABSTRACT FROM AUTHOR]