A cyclotron beam intensity modulation method with safe self-locking function

Abstract

The invention discloses a cyclotron beam intensity modulation method with a secure self-locking function. A first vertical deflection plate and a second vertical deflection plate are sequentially placed on a DEE plate or a Dummy DEE in a central region of a cyclotron, a beam baffle is placed between the first vertical deflection plate and the second vertical deflection plate, the proportion of particles passing through the beam baffle is changed by adjusting the voltage on the first vertical deflection plate and the second vertical deflection plate, and thus the beam intensity modulation and the beam shutting off can be implemented; and when a power supply of the vertical deflection plates fails, the power-off protection can be automatically performed, and the particles are completely hitonto the beam baffle. According to the scheme of the invention, the beam intensity modulation and the beam shutting off can be achieved by changing the voltage of the vertical deflection plates, the whole process is controlled by a power supply system outside the cyclotron, and the method is convenient and effective; and when the power supply system fails, the beams are completely hit onto the baffle to automatically perform a shutting off operation, and the secure self-locking can be provided for the equipment and personnel.

Description

technical field [0001] The invention belongs to the field of cyclotrons, and in particular relates to a cyclotron beam intensity modulation method with a safe self-locking function. Background technique [0002] In proton radiation therapy, the treatment head needs beams of different intensities to irradiate the tumor to achieve the expected therapeutic effect, so the whole system needs to have the function of adjusting the beam intensity to prevent the patient from being exposed to excessive radiation, which requires the design of the corresponding beam intensity The regulating device adjusts the beam current intensity. The traditional current intensity adjustment method is to use the vertical deflection plate and beam collimator installed in the central area, and form a vertical electrostatic field between the deflection plates, so that part or all of the beam hits the beam collimator and loses switch to achieve flow intensity adjustment. This traditional method of adjus...

AI Technical Summary

Problems solved by technology

This traditional method of adjusting the current intensity does not have the function of safety self-locking. Once the power supply itself fails, it will cause a power outage and cannot provide enough voltage to deflect ions to realize the shutdown of the beam current. It can only be indirectly controlled by safety interlock control. cut beam

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