RESEARCH DIRECTED TOWARD THE DEVELOPMENT OF A LOW-ENERGY ELECTRON GUN.

A low-energy electron gun of high current in tensity was designed and developed, which will transmit 140 microamperes at 10 volts over a drift distance of 1 cm. The energy spread at half-height is less than a volt. Theoretical limits on the allowed current densities were formulated and verified experimentally within a factor of five. Space charge effects in electron beams were considered with respect to producing a monoenergetic beam. Electron beams with cur rents over a milliampere and potentials less than a few volts require cross sectional areas that are prohibitive if the beam is transmitted over distances greater than a centimeter. Other con siderations as to the design of a high-intensity, low-energy electron spectrometer are reviewed. Author