Phase locked magnetrons as accelerator RF sources

The problems associated with operating magnetrons into accelerator cavities is well known. However, as the magnetron is a simple inexpensive device, compared with most other rf power tubes, it is an attractive candidate for future accelerator rf systems. A test standard has been constructed at GA and has operated a Varian VMP 1702 425 MHz magnetron at a peak power level of 2 MW and a nominal pulse length of 100 μs. Included in the test stand is a tetrode cavity amplifier, also at 425 MHz, with a maximum peak power capability of 250 kW. The amplifier is driven by a solid state oscillator. The intent of the program is to use the tetrode amplifier output to phase lock the magnetron to produce an rf pulse having characteristics suitable for accelerator applications