Optically powered charged particle accelerator

摘要

A charged particle control apparatus provides very high voltage particle beams. One or more photocell arrays provide bias voltages for beam accelerating stages. The arrays are made from a number of microfabricated photocells connected in series to produce a voltage output that is the sum of the voltages from the individual cells. Arrays of each stage are connected in series to produce a cumulative stage voltage that is applied to an accelerating electrode made part of the stage. These accelerating stages are disposed within a transparent vacuum chamber and are spaced from a charged particle source stage disposed near one end of the chamber. This charged particle source stage includes an emission source such as a photocathode. The photo arrays of the accelerating stages are connected in series to produce a potential that is applied to the particle source stage. Optical power illuminates the stages to generate desired voltage biases to the accelerating electrodes. A light source is used to excite the photocathode when this emission source is used. Electrons from the emission source are accelerated by the accelerating electrodes and are emitted from the chamber which is typically conjoined with other apparatus. By utilizing photocell arrays to generate beam current and accelerating biases, as well as a photocathode for providing a source of electrons, the apparatus of the invention is completely optically isolated thereby requiring no direct electrical connections to the apparatus even though multiple accelerating stages are used to facilitate the achievement of very high voltage particle beams.