Operating Characteristics of the Electro-Optical Shutter

Abstract

The electro-optical shutter is being employed at the University of California in the study of the electrical breakdown of gases and liquids. In these studies it is desirable to know the time it takes the shutter to close. A calculation of this time can be made from the electrical constants of the circuit and a knowledge of the rate at which the voltage drops across the spark gap. For some of the experimental conditions it is sufficiently accurate to base these calculations on an electrical circuit which replaces the actual distributed constants by lumped constants. In other cases however the error involved by this assumption is too great. It is the purpose of this paper to present an accurate solution of the electrical circuit taking into consideration that the constants are distributed, and by means of this solution to bring out the following important facts: (1) For relatively large distributed electrical capacities of the Kerrcell leads the rate of closing of the shutter is greater than indicated by the lumped constant solution. (2) The rate of closing is materially increased by using leads separated only by a sheet of mica instead of spacing them farther apart in air. For completeness the results of a few experimental observations are also given and compared with results obtained by calculation.