Particle-matter interactions

Electron beams Particle-matter interactions > (a) Inelastic interactions (energy transfer with sample species) SPECTROSCOPY (b) Elastic interactions (energy transfer) DIFFRACTION, MICROSCOPY... 

Since in the radiation chemical practice mostly accelerated electron irradiation and y-ray irradiation are applied, a brief summary will follow on the energy absorption of these particles in matter. The basic particle-matter interaction types are discussed in Chap. 8 of Vol. 1 that chapter approaches this problem from the side of the particle and concentrates on the question how the particle loses its energy. The main interaction types will also be mentioned here however, the details will only be discussed in connection with the question of how the molecules gain energy from the energetic particles. 

The atomic scattering factor for electrons is somewhat more complicated. It is again a Fourier transfonn of a density of scattering matter, but, because the electron is a charged particle, it interacts with the nucleus as well as with the electron cloud. Thus p(r) in equation (B1.8.2h) is replaced by (p(r), the electrostatic potential of an electron situated at radius r from the nucleus. Under a range of conditions the electron scattering factor, y (0, can be represented in temis... 

The above observation suggests an intriguing relationship between a bulk property of infinite nuclear matter and a surface property of finite systems. Here we want to point out that this correlation can be understood naturally in terms of the Landau-Migdal approach. To this end we consider a simple mean-field model (see, e.g., ref.[16]) with the Hamiltonian consisting of the single-particle mean field part Hq and the residual particle-hole interaction Hph-... 

In this chapter we introduce some of the fundamental concepts needed to understand how light interacts with matter. We start by examining a system of classical charged particles that interacts with a pulse of electromagnetic radiation. We then quantize the particle variables and develop the semiclassical theory of light interacting with quantized particles. The details of the derivations are not required for subsequent chapters. However, the resultant equations [Eqs. (1.50) to (1.52)] form the basis for the theoretical development presented in Chapter 2, which deals with both the interaction of weak lasers with molecules and with photodissociation processes. 

Beta particle—One type of radioactive decay particle emitted from radioactive atomic nuclei. A beta particle is the same thing as an electron. Cross section—measure of the probability that a subatomic particle will interact with matter. 

Now there seems to be one immediate and important question to be addressed if the particle and wave pictures of light are two versions of the same thing, how can we understand nonlinear light-matter interactions when the electric field is represented by a plane wave The answer lies in a generalization of Eq. (2) which lets the polarization be expressed as a Taylor series in the electric field strength... 

The pioneering work of Bohr [1] on the slowing down of swift alpha particles in matter defines one of the main events opening the way to modern physics. The ion-matter interaction depends crucially on the ion velocity in the high... 

Electrons are charged particles and interact very strongly with matter. This has two consequences for... 

Indeed, the particle interaction with the dilute media depends on their relative velocity but also on various other parameters. E.g., we can assume that the particle directly interacts with the (dark-matter) medium (via a heavy intermediate boson) and the interaction with light is indirect and somewhat weaker. Or on the contrary we can suggest that the dilute medium is weakly coupled to the light directly and... 

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