Multi-signal-source selection circuit of modulator and control method of multi-signal-source selection circuit

Abstract

The invention discloses a multi-signal-source selection circuit of a modulator and a control method of the multi-signal-source selection circuit. The multi-signal-source selection circuit comprises anupper computer, a control CPU, a signal source selection circuit and a plurality of signal source storage circuits connected in parallel, wherein the number of the signal sources is in one-to-one correspondence with accelerator energy gears; the upper computer is controlled to output an accelerator energy gear signal; the control CPU generates a chip selection code according to the energy gear signal and sends the chip selection code to the signal source selection circuit; the signal source selection circuit controls the corresponding signal source to work according to the chip selection code; when the accelerator needs to work at a high-energy gear, the signal source selection circuit is controlled to select a signal source with relatively low maximum repetition frequency and more charging pulses in each repetition period; and when the accelerator needs to work at a low-energy gear, the signal source selection circuit is controlled to select a signal source with relatively high maximum repetition frequency and fewer charging pulses in each repetition period. The dose rate of the low-energy end of the accelerator can be improved according to the invention.

Description

technical field [0001] The invention belongs to the technical field of electron linear accelerators used in radiotherapy, and in particular relates to a multi-signal source selection circuit of a modulator and a control method thereof. Background technique [0002] Medical electron linear accelerator is mainly composed of modulator, microwave source, electron gun, accelerating tube, collimator and other main parts, and its core component - modulator is an electrical component with high power and strong interference. It is a relatively safe and reliable way for the modulator to use a flyback charging transformer to charge the pulse forming network. There is a fixed signal source in the control circuit of this modulator, which will generate a group of pulse signals to control the primary energy storage of the charging transformer. [0003] Due to the magnetic core characteristics of the charging transformer and other reasons, the maximum width of each charging pulse and the m...

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Problems solved by technology

However, due to the influence of a single signal source, once the highest energy level is determined, the maximum emission frequency of the low-energy level beam will also be determined, and the goal of increasing the dose rate cannot be achieved

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