Abstract: A circular accelerator for extracting a charged-particle beam is arranged to increase displacement of the beam by the effect of the betatron oscillation resonance and increase the betatron oscillation amplitude of the particles, which have initially betatron oscillation within the stability limit for the resonance, to exceed the stability limit thereby extracting the particles exceeding the stability limit of the resonance.

Abstract: An acceleration device for charged particles has an acceleration cavity through which passes a beam of the particles. High frequency power from a suitable source is transmitted to the cavity via a suitable transmission means (antenna) to transmit the energy to the particles and so accelerate them. The transmission means is controlled by a suitable control to control the coupling constant of the transmission means when power is applied. Also, the device may have a looped conductor in the cavity controlled by the control to couple to the field in the cavity and to extract power from the field, thereby to control the de-tuning of the applied power relative to the power transmitted to the particles. By controlling the coupling constant and/or the de-tuning, power may be transmitted efficiently to the beam of particles.

Abstract: When accelerating charged particles on synchrotron acceleration basis by using a circular accelerator having a RF acceleration cavity, the detuned amount representative of an offset between oscillation frequency of a RF oscillator for the RF acceleration cavity and resoance frequency of the RF acceleration cavity and the RF power for supplying the charged particles with energy are controlled in compliance with changes in energy of the charged particles without changing the oscillation frequency. A great number of charged particles injected into the circular accelerator can be accelerated to the ultimate storage energy during the acceleration on synchrotron acceleration basis without causing charged particle beam loss.

Abstract: A lift control system includes a spatial filter producing a signal having various features, a discriminator for discriminating one or more features of the signal, and for producing a control signal when at least one of the features discriminated falls in a predetermined range, and active devices connected to the discriminator. The active devices are made active upon receipt of the control signal.