Development of ferrite line pulse sharpeners

A variety of applications including intense electron beam control, EMP generation, wideband radar, and Pockels cell drivers require subnanosecond rise-time pulses with amplitudes of tens of kilovolts. At voltages above 10 kV, the use of ferrite-loaded coaxial transmission lines in conjunction with slower primary switching devices such as thyratrons or triggered spark gaps is a practicable means of reducing initial rise-times of the order of 2-20 ns to subnanosecond output rise-times. The ferrite line is interposed between the pulse generator and the load; generally systems are designed to work at 50 ohms, with coaxial lines linking the system elements. Typically, input rise-times to the ferrite line may be of the order of 2-20ns. The authors discuss the pulse sharpening mechanism, DC current bias, bias using magnets, and numerical analysis.<>