Varian Medical Systems Particle Therapy Gmbh

Varian Medical System Particle

Thomas Stephani

Uwe Behrens

Jan Timmer

Heinrich Roecken

Christian Baumgarten

Heinrich Rocken

Heinrich Röcken

Beam current variation system for a cyclotron, arranged in the inner center of the cyclotron, downstream from the ion source generating the charged particle beam, the system comprising a deflector system powered by a voltage and a collimator. The beam is dumped in the collimator, if the deflector system () is not powered, and the beam is switched on by powering the deflector system with a voltage.

Beam current variation system for a cyclotron

Systems and methods are provided to perform efficient, automatic cyclotron initialization, calibration, and beam adjustment. A process is provided that allows the automation of the initialization of a cyclotron after overnight or maintenance imposed shutdown. In one embodiment, five independent cyclotron system states are defined and the transition between one state to another may be automated, e.g., by the control system of the cyclotron. According to these embodiments, it is thereby possible to achieve beam operation after shutdown with minimal manual input. By applying an automatic procedure, all active devices of the cyclotron (e.g., RF system, extraction deflectors, ion source) are respectively ramped to predefined parameters.

System and method for automated cyclotron procedures

Systems and methods are provided to perform efficient, automatic adjustment of cyclotron beam currents within a wide range for multiple treatment layers within the same patient and treatment session. In one embodiment, efficient adjustment is achieved by using beam current attenuation by an electrostatic vertical deflector installed in the inner center of the cyclotron. The beam current may, for example, be adjusted by the high voltage applied to the electrostatic vertical deflector. In front of each treatment the attenuation curve of the vertical deflector is recorded. Based on this attenuation curve, the vertical deflector voltage for the needed beam current of each irradiation layer is interpolated. With this procedure the beam current could be automatically adjusted in minimal time over a wide range while maintaining a high level of precision.

System and method for layer-wise proton beam current variation

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Bergisch Gladback, Germany

Thomas Stephani