Charged particles secondary electrons generation

Physically the generation of X-rays is often a secondary process preceded hy the ionization of an atom. There are, therefore, several possihilities of X-ray generation depending on the type of the exciting medium - neutrals or charged particles such as electrons and ions and high-energy photons, i. e. X-rays themselves. 

Ionizations produced by electrons generated in the primary interaction of the incident fast charged particle are called secondary. The definition may be extended to all successive generations if sufficient energy is available. In this sense, secondary ionization is very... 

The choice of detector for charged particles (electrons or positive/negative ions) depends on the design of a particular instrument and the type of experiment. Basically, the detector generates a signal from incident electrons or ions, either by directly inducing a current or by generating secondary electrons, which are further amplified. The three most common types are described below. 

The discussion up to this point has been limited to the effects of the ionization produced directly by the incident particle. This is called primary ionization. There are types of gas counters in which the electric field is so strong that the electrons of the primary ionization acquire enough kinetic energy between collisions to produce new electron-ion pairs. These new charges constitute the secondary ionization. Primary and secondary ionization are generated within such a short period of time that they contribute to one and the same pulse. 

There is also evidence that vibrationally excited particles can appear as a result of charge exchange between ions [277] and also be generated by secondary processes in the chemical interaction of positive ions (generated by electron bombardment) with neutral molecules. This is consistent with the results obtained (see [146]) for secondary processes of the type + HgO + OH. 

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