ABSTRACT
This chapter considers the main physical principles of registration of nuclear particles. The ionization chamber is an instrument for quantitative measurement of ionization produced by charged particles in their passage through a gas. A proportional counter is simply an ionization chamber in which the effect of gas amplification is used. Analogous to gas ionization in the ionization chamber is the generation of free charge carriers in solids. The etching technique is very simple and has been well established for a range of solid state detectors and particles—from α-particles to fission fragments. Apart from ionization, some atoms and molecules are also excited to higher energy levels during the interaction of ionizing radiation with matter. In many physics experiments and radiological techniques it has become possible to record the intensity distribution of radiation in space and in time, sometimes accompanied by the energy of the ionizing particles or ionizing radiation.
