Pressure-regulating large-area windowless airflow proportional counter

A pressure-regulating large-area windowless airflow proportional counter, comprising:

• a chamber, having a side opening;
• a metal tray, configured to be moved into or out of the chamber via the side opening, wherein a large-area source is placed on the metal tray;
• a side cover, fixed to the side opening by an O-ring via a locking device to form an airtight structure;
• a gas cylinder, configured to supply a dedicated gas into the chamber via a gas inlet of the chamber;
• a voltage-input/signal-output terminal, configured to supply a voltage to an anode wire net, wherein free electrons generated by the large-area source due to an ionization phenomenon are collected by the anode wire net, and outputted to a voltage signal processing module through the voltage-input/signal-output terminal so as to analyze a pulse height or a pulse count;
• and
• a protection wire net, disposed between the anode wire net and the large-area source, wherein an electric field is mainly generated between the anode wire net and the protection wire net in order to avoid that a strength of the electric field is influenced due to a thickness of the large-area source.