proportsionaalloendurid

Proportsionaalloendurid, also known as proportional counters, are gas-filled radiation detectors that measure the energy of incident particles or photons. They operate by detecting the ionization produced by radiation within a gas-filled chamber. When a charged particle or photon enters the chamber, it ionizes the gas atoms, creating electron-ion pairs. An electric field is applied across the chamber, typically between a central anode wire and an outer cathode cylinder. The free electrons are accelerated towards the anode, and as they gain energy, they collide with other gas atoms, causing further ionization. This process, known as gas multiplication or an avalanche effect, amplifies the initial ionization signal.

The key characteristic of a proportional counter is that the amount of charge collected is directly proportional to the initial energy deposited by the incident radiation. This proportionality allows for energy spectroscopy, where the detector can distinguish between different types and energies of radiation. The operating voltage applied to the detector determines the regime of operation. In the proportional region, the avalanche is contained and does not spread throughout the entire detector, preserving the proportionality of the signal.

Proportional counters are versatile and can be designed to detect various types of radiation, including alpha particles, beta particles, X-rays, and gamma rays. Their sensitivity and energy resolution make them valuable instruments in fields such as nuclear physics, particle physics, medical imaging, and industrial radiography. The choice of fill gas and operating pressure can be tailored to optimize the detection efficiency and energy response for specific applications.