TRANSIENT-BEHAVIOR OF THE TERMINAL VOLTAGE IN A RECIRCULATING ELECTROSTATIC ACCELERATOR FOR A LONG-PULSE FREE-ELECTRON LASER

For long-pulse, single-mode operation of free-electron lasers, transie nt behavior of the terminal voltage in a recirculating electrostatic a ccelerator is analyzed. It is found that the rate of terminal voltage drop depends on the position where the current loss of electron beam o ccurs. The rate is measured to be 507 V/A mu s for the current loss in the terminal and 100 V/A mu s for the current loss in the deceleratio n tube. By increasing the capacitances between the adjacent electrodes of a deceleration tube, the accelerator becomes more stable with low rate of terminal voltage drop and increased recovery efficiency. (C) 1 996 American Institute of Physics.