| 摘要 |
PURPOSE:To perform the process stably by a method wherein a part of reflected waves of microwaves are fed back to a magnetron while the state of magnetron and microwave circuit is monitored. CONSTITUTION:The oscillated microwaves are fed from slits on anode wall to waveguides 24 and the reflected waves contained in the microwaves enter from the slits to a magnetron to be synthesized in the electromagnetic field of operational space resultantly changing the shape of electron cloud 23. Even in case the magnetron is in normal operation, the frequency is subject to a bit of fluctuation due to e.g. thermal expansion while the magnetron will be subject to remarkable fluctuation in oscillation frequency due to the deterioration in electron emission from an anode 21 causing remarkable fluctuation in phase difference in reflected waves as well as change of electron cloud 23. Therefore, moderate amount of reflected waves are fed back; anode current form is monitored; and the changes in state of magnetron and microwave circuit are detected. Finally it is empirically recommended that applicable reflected waves shall be equivalent to the power around 10% of normal incident waves from a microwave power supply 1. |
