elektronsokszorozáson

Elektronsokszorozás, meaning electron multiplication, is a phenomenon where a single initial electron can trigger the creation of many more electrons. This process is fundamental to the operation of various electronic devices, particularly those involving gas ionization or vacuum environments. In gas-filled detectors like Geiger-Müller counters, an initial electron, accelerated by a strong electric field, collides with gas atoms. These collisions can ionize the gas atoms, releasing more electrons. These secondary electrons are then also accelerated and cause further ionizations, leading to an avalanche effect. This rapid multiplication amplifies a small initial ionization event into a detectable electrical pulse.

In vacuum tubes, such as photomultiplier tubes, elektronsokszorozás occurs through secondary emission. When energetic electrons strike a surface, they can dislodge multiple secondary electrons from that surface. This is often achieved by using dynodes, which are specially designed electrodes. An electron arriving at a dynode causes the emission of several secondary electrons. If these secondary electrons are then accelerated to strike another dynode, the process repeats, with each dynode stage generating a greater number of electrons than the previous one. This cascaded multiplication is crucial for amplifying the weak signals produced by individual photons detected by photomultiplier tubes. The efficiency of this multiplication is characterized by the secondary emission yield, which is the average number of secondary electrons emitted per incident primary electron.