Energy Loss Of Fast Particles Research Articles

New solution of the Landau kinetic equation for the energy loss of fast particles in crystals

A solution of the Landau kinetic equation for the energy loss of fast particles in crystals has been constructed in the form of a series, each term of which corresponds to the Gaussian distribution. The calculated results are compared with the experimental ones.

Energy loss of fast particles in course of their transition across electron gas plates

The stopping power of fast charged particles passing through an electron gas layer of a metal in the direction normal to the layer surface has been calculated quantum-mechanically for several metals. The origin of the stopping power is the Coulomb interaction between the particle and the electron gas in the layer. A comparison between the theoretical and experimental stopping power for protons is performed in the paper.

Energy loss of fast particles in confined atomic systems at very high temperatures.

Using a self-consistent description of an inhomogeneous electron gas in thermal equilibrium, we formulate a simple model for the stopping power of confined atomic systems at high temperatures. The model is based on previous studies of the energy loss of particles in partially degenerate plasmas. We describe the thermal enhancement of the energy loss in pellet fusion targets, in accord with recent experiments, and we explain this behavior in terms of quantum-mechanical and thermal effects in partially degenerate systems.

An electron gas approach to the energy loss of charged particles in solids: the confined-atom model

The author presents a model to describe the energy loss of fast particles in solids that is based on the Thomas-Fermi model for an electron gas of variable density, with boundary conditions corresponding to an atomic system confined within a Wigner-Seitz cell in the solid. The model explains the oscillations of the stopping cross section as a function of the atomic number Z2 of the solid element, as well as the fluctuations in the mean excitation energy I0=I/Z2.

Z3corrections to the scattering of electrons and positrons in atoms and to the energy loss of fast particles in solids

A calculation of the elastic scattering cross section for the screened Coulomb potential of a charge Ze provides second-order terms, of relativistic and nonrelativistic origin, that are proportional to Z/sup 3/. Here we study the Z/sup 3/ effects in the elastic scattering of electrons and positrons in atoms and in the energy loss of fast charged particles in solids, for a wide range of energies. Owing to the Z/sup 3/ effect, the scattering of electrons in atoms becomes always larger than the scattering of positrons. In the relativistic limit this agrees with the result of McKinley and Feshbach for bare nuclei. The screening effect introduces a nonrelativistic enhancement of the Z/sup 3/ correction; this increases the asymmetry between electron and positron scattering. Using the same approach we calculate the contribution from close collisions to the Z/sup 3/ correction in the energy loss of fast particles in solids. For nonrelativistic velocities the Z/sup 3/ correction shows a behavior similar to the result of Ashley, Ritchie, and Brandt, including distant and close collisions; in the relativistic limit we retrieve the result of Jackson and McCarthy. The limitations of this approach in describing distant collisions, and the validity of the partition rule, aremore » considered.« less

The Specific Primary Ionization and Energy Loss of Fast Electrons in Matter

By utilizing the dependence of the efficiency of a Geiger-Mueller counter upon the primary ionization of a counted particle, the primary ionization by electrons in hydrogen has been determined for energies in the range 0.2 Mev to 9.0 Mev. The relative stopping powers of carbon and ${\mathrm{H}}_{2}$O have also been investigated, the results yielding evidence for the existence of a polarization effect which reduces the energy loss of fast particles in condensed matter. Experimental results are compared with those of the Bethe-Bloch theory and the Halpern-Hall theory which takes into account the polarization properties of the medium.