LASER HEATING MECHANISM FOR CATHODE OF ELECTRON GUN

摘要

PURPOSE:To provide a cathode heating mechanism for an electron gun which stably operates at the time of the high-output and the long-hour operation by protecting the whole mechanism against collateral radiation beams from the cathode and laser reflected beams. CONSTITUTION:A waveguide 12 having a conical tip in which an inner reflecting cover (for example, gold coating) is applied between a cathode 1 and an optical fiber for transmitting a laser beam is arranged. An incoming laser beam 7 is directly incident thereupon and then is converged into a predetermined position with plural times of reflection performed within the cone waveguide to emit a laser beam. The laser beam 7 is applied to the cathode 1 as it is, thereby performing heating operation.