| 摘要 |
PURPOSE:To prevent a Robinson's instability and to maintain the resonant frequency constant by regulating a bias voltage to set the resonant frequency of a high-frequency accelerator cavity slipping a specific value responding to the phase slippage amount from the operating frequency. CONSTITUTION:To the input terminal 11 of an automatic frequency tuning circuit 10, a phase difference voltage Vp variable in the scope of + or -0.5V responding to the phase difference phi is applied. However, in order to avoid a beam instability which is called Robinson's instability, the resonant frequency fo of a high-frequency accelerator cavity 1 must be set at a value a little slipped to the operating frequency fd of a high-frequency power source 5. For this purpose, the switch SW in a bias voltage setting device 19 is selected to the negative electrode side, and a variable resistor VR2 is regulated to set a negative bias voltage Vb responding to the phase slippage amount DELTAphi. |
