초록 ▼

A method and a system for obtaining a proper resonance of the RF electrodes when using a preset or predetermined stable frequency oscillator in a cyclotron accelerator without using mechanical tuning devices. In order to maintain a high RF electrode voltage during operation the RF electrode system r

A method and a system for obtaining a proper resonance of the RF electrodes when using a preset or predetermined stable frequency oscillator in a cyclotron accelerator without using mechanical tuning devices. In order to maintain a high RF electrode voltage during operation the RF electrode system resonance is monitored and the frequency of the stable frequency generator is controlled by a feedback system continuously monitoring the matching of the oscillator output frequency and the resonance of the RF electrode system. Necessary small adjustments of the stable oscillator frequency to maintain a maximum matching to the resonance frequency of the RF electrode system are obtained by means of the feedback system to the stable oscillator. The feedback system relies on measured values obtained by a load phase sensor monitoring the output of the final RF power amplifier. A cyclotron control system in turn obtains the set and corrected oscillator frequency value and fine tunes further the magnetic field created in the accelerator device according to the frequency information obtained.

대표청구항 ▼

1. A method for providing automatic frequency tuning for an RF electrode accelerating system (10) in a cyclotron device (3) for production of PET isotopes comprising the steps of:generating an RF signal at predetermined frequency in a controlled frequency oscillator (5) and amplifying said predeterm

1. A method for providing automatic frequency tuning for an RF electrode accelerating system (10) in a cyclotron device (3) for production of PET isotopes comprising the steps of:generating an RF signal at predetermined frequency in a controlled frequency oscillator (5) and amplifying said predetermined RF signal by means of an amplifier chain (6, 7) to obtain a driving RF power for feeding an RF electrode system (10) within a cyclotron cavity; outputting the driving RF power to a matched power transmission line (2) connected to and feeding said RF electrode system (10) to thereby producing a high voltage at the RF electrode system (10); detecting a load phase by means of a load phase sensor (8) connected between a final power amplifier (7) and the power transmission line (2); feeding the detected load phase to a feedback amplifier (9) thereby creating an error signal fed back to the frequency oscillator (5) to thereby optimise the frequency of the controlled frequency oscillator (5) for optimum matching to a resonance frequency of the RF electrode system (10); and measuring the frequency fed to the RF electrode system by means of a cyclotron control system (4), in turn controlling a magnetic field applied to the cyclotron for obtaining an optimum balance between the magnetic field and the accelerating RF voltage applied to the RF electrode accelerating system in the cyclotron.