Transient response of a X-band magnicon amplifier

The paper reports the transient response of the X-band magnicon amplifier as a function of drive frequency and of the magnicon operating parameters, including beam voltage and axial magnetic fields. It is found that the peak in the frequency spectrum of the output pulse is different than twice the frequency of the drive pulse unless the drive pulse was exactly at the center of the magnicon gain curve. As the drive pulse is tuned away from this frequency, the frequency of the output pulse is pulled by an amount proportional to the frequency difference. Typically, the constant of proportionality is -10%, so that a 5 MHz change in the drive frequency, which normally produce a 10 MHz change in the output frequency, only changes the short-pulse output frequency by ~1 MHz. In order to change the short-pulse output by larger amounts, it is necessary to tune the gain curve by changing the magnicon gun voltage and axial magnetic fields. These results is be compared to simulations and theoretical predictions.