Circuit arrangement for acquiring signals from a device for measuring charged particle beams for external radiotherapy

The technology concerns a circuit configuration for the acquisition of signals from an apparatus used in the measurement of charged particle beams used in external radiotherapy, in particular protons, carbon ions and other ionic species, generated by particle accelerators.

How does it work?

The technological configuration comprises a sensor equipped with ionization chambers, which in turn consists of a plurality of sensor channels. The circuit layout is formed by a series of channel branches arranged in parallel, set up to be connected to the respective sensor channels in order to receive input signals. Each channel branch includes a current-frequency converter and a counter, which provides a count value representative of the charge detected by a given channel. The signals thus processed can be routed to a single parallel output via a multiplexer.

The circuit layout described can operate with ionization chamber sensors whose channels are arranged in a stack that develops along the beam direction, but they can also operate with two-dimensional sensors, known as pixel ionization chamber detectors.

Applications

• Quality control;
• Nuclear medicine (hadrontherapy);
• Accelerators.

Advantages

• Better accuracy in measuring low current regimes;
• Monitoring and adjusting the physical parameters of the particle beam during therapy;
• Greater reading flexibility;
• It avoids system saturation;
• Noise reduction.