Interaction of p-Particles with Matter

In the case of P-particles, their ionizing action in a unit of route length (specific ionization) is less, and their penetrative capacity is accordingly more in comparison with a-particles. Passing through matter, P-particles easily disperse. As a result, the trajectories of P-particles in substances exceed 1.5-4 times the thickness of the passed layer. So, the path of P-particles in a substance 

FIGURE 1.2 Dependence of the nnmber of a-particles on the distance from the source. N is the number of a-particles on the distance Z -dN/dl is the number of a-particles with the path Z R is the medium path of a-particles. 

When an electron flow arrives at the surface of a material, a part of particles can be reflected on the angle major 90°. This effect is named as reverse dispersion of electrons and used to resolve a series of applied problems, e.g., to determine the width of hlms. The same effect could be a source of methodical errors, in particular working with electron flows, leading to an increase in the number of particles, and moving to the counter due to their dissipation in the material. 

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