Patent ID: 6417634
Filing Date: 2002-07-09
Classification: H05H,Y02E

Abstract:
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.