| 摘要 |
<p>This device allows the variation of the coupling between two points in an RF circuit in a very simple way whilst maintaining the RF phase relationship and varying the relative magnitude of the RF fields. The device is characterised by a simple mechanical control of coupling value, that has negligible effect on the phase shift across the device. This is achieved by the simple rotation of the polarisation of a TE111 mode inside a cylindrical cavity. Such a device does not contain resistive elements, and the sliding mechanical surfaces are free from high RF currents. This device finds an application in standing wave linear accelerators, where it is desirable to vary the relative RF field in one set of cavities with respect to another, in order that the accelerator can operate successfully over a wide range of energies.</p> |
