Patent Number: 
Section: claims

1. A synchrocyclotron comprising:a magnetic field generator;a resonant circuit, comprising:electrodes, disposed between magnetic poles, having a gap therebetween across the magnetic field; anda variable reactive element in circuit with the electrodes to vary the resonant frequency of the resonant circuit; anda voltage input to the resonant circuit, the voltage input being an oscillating voltage that varies over the time of acceleration of charged particles, wherein the amplitude and the frequency of the voltage are varied;said synchrocyclotron further including:an ion source for injecting charged particles into the synchrocyclotron;an extraction electrode, disposed between the magnetic poles to extract a particle beam from the synchrocyclotron;one or more sensors for detecting resonant conditions in the resonant circuit wherein the frequency of the voltage input is adjusted to maintain the resonant conditions;means for controlling the reactance of the variable reactive element and adjusting the resonant frequency of the resonant circuit to maintain the resonant conditions;a beam monitor for measuring particle beam, at least one of the voltage input, the ion source and the extraction electrode being controlled to compensate for variations in the particle beam, andwherein the oscillating voltage input is generated by a programmable digital waveform generator. 2. The synchrocyclotron of claim 1 wherein the programmable waveform generator controls at least one of the ion source and the extraction electrode to compensate for variations in the particle beam. 3. A synchrocyclotron comprising:a magnetic field generator;a resonant circuit, comprising:electrodes, disposed between magnetic poles, having a gap therebetween across the magnetic field; anda variable reactive element in circuit with the electrodes to vary the resonant frequency of the resonant circuit; anda voltage input to the resonant circuit, the voltage input being an oscillating voltage varied over the time of acceleration of charged particles by a programmable digital waveform generator. 4. The synchrocyclotron as claimed in claim 3 wherein the amplitude of the voltage input is varied. 5. The synchrocyclotron as claimed in claim 3 wherein the frequency of the voltage input is varied. 6. The synchrocyclotron of claim 3 wherein the amplitude and the frequency of the voltage are varied. 7. The synchrocyclotron of claim 6 further including an ion source, controlled by a signal from the programmable digital waveform generator, for injecting charged particles into the synchrocyclotron. 8. The synchrocyclotron of claim 7 further including an extraction electrode, disposed between the magnetic poles, controlled by a signal from the programmable digital waveform generator, for extracting a particle beam from the synchrocyclotron. 9. The synchrocyclotron of claim 8 further including one or more sensors detecting resonant condition in the resonant circuit. 10. The synchrocyclotron of claim 9 wherein the programmable digital waveform generator is adjusting the frequency of the voltage input to maintain the resonant conditions. 11. The synchrocyclotron of claim 10 further including means for controlling the reactance of the variable reactive element and adjusting the resonant frequency of the resonant circuit to maintain the resonant conditions. 12. The synchrocyclotron of claim 11 further including a beam monitor for measuring particle beam, the programmable waveform generator controlling at least one of the voltage input, the ion source and the extraction electrode to compensate for variations in the particle beam. 13. The synchrocyclotron of claim 12 wherein the beam monitor measures particle beam intensity. 14. The synchrocyclotron of claim 12 wherein the beam monitor measures particle beam timing. 15. The synchrocyclotron of claim 12 wherein the beam monitor measures spatial distribution of the particle beam. 16. A synchrocyclotron comprising:a magnetic field generator;a resonant circuit, comprising:electrodes, disposed between magnetic poles, having a gap therebetween across the magnetic field; anda variable reactive element in circuit with the electrodes to vary the resonant frequency of the resonant circuit; anda voltage input to the resonant circuit, the voltage input being an oscillating voltage that varies over the time of acceleration of charged particles, andfurther including an ion source and an extraction electrode, wherein at least one of the ion source and the extraction electrode is controlled by the programmable waveform generator to compensate for variations in a particle beam. 17. A method of producing a particle beam in a synchrocyclotron, comprising:injecting charged particles into a synchrocyclotron by an ion source;applying oscillating voltage input to a resonant circuit, comprising accelerating electrodes having a gap therebetween across a magnetic field, to create an oscillating electric field across the gap and accelerating charged particles, the oscillating voltage being controlled to vary over the time of acceleration of the charged particles, wherein the amplitude and the frequency of the voltage are varied; andextracting the accelerated charged particles by an extraction electrode to form a particle beam,said method further including:detecting resonant conditions in the resonant circuit wherein the frequency of the voltage input is adjusted to maintain the resonant conditions;adjusting reactance of a variable reactive element in circuit with the oscillating voltage input and the accelerating electrodes to maintain the resonant conditions in the resonant circuit:measuring particle beam intensity by a beam monitor; andcontrolling at least one of the oscillating voltage input, the ion source and the extraction electrode to compensate for variations in the particle beam,wherein the oscillating voltage input is generated by a programmable digital waveform generator. 18. The method of claim 17 wherein the programmable waveform generator controls at least one of the ion source and the extraction electrode to compensate for variations in the particle beam. 19. A method of producing a particle beam in a synchrocyclotron, comprising:injecting charged particles onto a synchrocyclotron by an ion source;applying oscillating voltage input to a resonant circuit that comprises accelerating electrodes having a gap therebetween across magnetic field, to drive an oscillating electric field across the gap and accelerating charged particles, the voltage input having a variable amplitude and frequency determined by a programmable digital waveform generator; andextracting the accelerated charged particles by an extraction electrode to form a particle beam. 20. The method of claim 19 wherein the amplitude of the oscillating voltage input is varied. 21. The method of claim 19 wherein the frequency of the oscillating voltage input is varied. 22. The method of claim 19 wherein the amplitude and the frequency of the voltage are varied. 23. The method of claim 22 further including measuring the oscillating voltage and or current in the circuit to detect resonant conditions in the resonant circuit. 24. The method of claim 23 wherein the frequency of the voltage input is adjusted to maintain the resonant conditions. 25. The method of claim 24 further including adjusting reactance of a variable reactive element in circuit with the oscillating voltage input and the accelerating electrodes to maintain the resonant conditions in the resonant circuit. 26. The method of claim 25 further includingmeasuring the particle beam by a beam monitor; andcontrolling at least one of the voltage input, the injection electrode and the extraction electrode by the digital waveform generator to compensate for variations in the particle beam. 27. The method of claim 26 wherein the beam monitor measures particle beam intensity. 28. The method of claim 26 wherein the beam monitor measures particle beam timing. 29. The method of claim 27 wherein the beam monitor measures spatial distribution of the particle beam. 30. The method of claim 19 further including detecting resonant conditions in the resonant circuit. 31. The method of claim 19 further including detecting variations in a particle beam. 32. The method of claim 19 further including adjusting the frequency of the voltage input generated by the digital waveform generator to maintain the resonant conditions. 33. The method of claim 19 further including controlling at least one of the ion source and the extraction electrode to compensate for variations in a particle beam by the digital waveform generator.