Corrections For Relativistic Effects Research Articles

Computations of relativistic LEED intensities and spin-polarisations for tungsten (001)

The effects of relativistic corrections in low-energy electron diffraction intensity calculations are assessed by reference to relativistic and non-relativistic computations for tungsten (001). Small changes are observed in the calculated intensities and band structures and a significant degree of spin-polarisation is predicted for the diffracted beams. The spin-polarisation profiles are more complicated than those observed in gas-phase experiments because of the influence of multiple scattering. The results suggest that LEED could provide a strong source of polarised electrons for use in scattering experiments. It is suggested that in future LEED experiments both spin-polarisation and intensity measurements should be performed on the diffracted electron beams.

Relativistic Corrections in the Theory of Muon Capture

Computations are presented in closure approximation on the effect of relativistic corrections (\ensuremath{\sim}[velocity of capturing proton]/[velocity of light]) on calculated muon total capture rates. A numerical estimate is made for the cases ${\ensuremath{\mu}}^{\ensuremath{-}}+_{2}\mathrm{He}^{3}\ensuremath{\rightarrow}_{1}\mathrm{H}^{3}+{\ensuremath{\nu}}_{\ensuremath{\mu}}$ and ${\ensuremath{\mu}}^{\ensuremath{-}}+_{2}\mathrm{He}^{4}\ensuremath{\rightarrow}_{1}\mathrm{H}^{4}+{\ensuremath{\nu}}_{\ensuremath{\mu}}$ and a comparison with experiment is given.

ENERGY LOSS OF HIGHLY CHARGED PARTICLES PRODUCED BY FISSION AND BY COSMIC RAYS: III. THE LINEAR DENSITY OF DELTA RAYS. EXPERIMENTS

Delta rays having an energy as low as 2–5 kev. have been counted along the tracks of mesons, protons, and α rays of low velocity, allowing the identification of each. Three methods are presented and applied to determine the efficiency ƒ of counting delta rays of various energies; measured values of ƒ vary between 0.05% at 2 kev. and 100–180% near 50 kev. The number of grains, and the energy distribution among visible delta rays, are analyzed. A new method of determining velocity, based on the analysis of the number of grains in the delta rays, is presented. In the Appendix, the effect of relativistic corrections is computed and discussed. It is small except at large velocities where comparison with experiment is difficult.