The magnetron-type varactor for fast control in accelerator RF systems

The RF test of the magnetron-type varactors have shown the proof of principle of this device. A comparison with the other power RF tunable devices, such as ferrite tuners, shows, that the varactor has a response time a few orders of magnitude shorter. In the experiments this time was estimated to be in the order of 10/sup -6/ sec for an operating frequency /spl ap/66 MHz. This feature of the varactor opens new applications of the varactor for a fast modulation (in order of few tens of the working RF period) of the amplitude and the phase of the accelerating voltage in the the RF cavities. Based on results of numerical simulation, different applications of the device for fast control and improvements in the design to reduce response time are considered.