A new experimental method utilizing a property of the gas laser has been developed that permits the measurement of the variation of the time of flight of electrons through a photomultiplier as a function of the position on the cathode from which they are emitted. The measurement of time variation is accomplished by comparing it with the distance traveled by a light beam during the same time and is capable of a time resolution of approximately 10<sup>-11</sup> sec.
JAMES D. REES, JR. and M. PARKER GIVENS, "Variation of Time-of-Flight of Electrons Through a Photomultiplier," J. Opt. Soc. Am. 56, 93-93 (1966)