Phase-lock loop synchronization between beam orbit and RF drive in synchrocyclotrons

摘要

The invention specifies the use of feedback in the radio frequency (RF) drive for a synchrocyclotron, controlling the phase and/or amplitude of the accelerating field as a means to assure optimal acceleration of the beam, to increase the average beam current and to alter the beam orbit in order to allow appropriate extraction as the beam energy is varied. The effect of space charge is reduced by rapid acceleration and extraction of the beam, and the repetition rate of the pulses can be increased. Several means are presented to monitor the phase of the beam in synchrocyclotrons and to adjust the phase and amplitude of the RF to optimize the acceleration of the beam and to adjust the extraction and injection of the beam. Also, the use of a pulsed ion source that matches the acceptance window of the synchrocyclotron is described.

主权项

1. A method of creating and extracting an ion beam having a desired energy from a cyclotron, wherein the cyclotron is operable over a wide range of energies, comprising:
introducing ions into said cyclotron; using a RF drive to accelerate the ions to move as an ion beam in said cyclotron; sensing a position of said ion beam within said cyclotron relative to a phase of the RF during said acceleration; using said position of said ion beam to alter said RF drive to maintain a desired acceleration; and extracting said ion beam, wherein said ion beam is extracted by actuating a non-axisymmetric pulsed magnetic field.