Asymmetry of bremsstrahlung by moderately relativistic polarized electrons

The asymmetry of bremsstrahlung by transversely polarized electrons using Sommerfeld–Maue wave functions has been calculated. In order to simplify the final formula the relativistic approximation has been used. The results obtained show a linear dependence of the asymmetry on the atomic number Z for the range 4≤Z≤26. It is shown that the approach developed gives the zeroth asymmetry for ultrarelativistic energies as expected but for initial electron energies ～5 MeV the asymmetry may achieve a magnitude ～8% (for Z=26). Polarimetry of electrons with energy higher than 1 MeV (where conventional Mott polarimeters have large experimental difficulties) may be carried out using the bremsstrahlung process providing a reasonable asymmetry and high cross section.     

The scattering of electrons by atomic hydrogen

A method is presented which reduces the problem to the scattering of a single electron in an equivalent potential. The complexities of the electron-electron interaction are embodied in this potential. An exact expression is given for the potential, and various approximation methods are discussed. The adiabatic approxmation is investigated and the imaginary part of the potential is examined.     

Vector meson production by inelastic scattering of polarized electrons off polarized nucleons

A general analysis of vector meson production by inelastic scattering of polarized electrons (or muons) off polarized nucleons is presented. Cross section and vector meson decay angular distribution are discussed in terms of s-channel helicity amplitudes for natural and unnatural parity exchange. The question of experiments suitable for analyzing the more refined dynamical features of ?⁰-production is discussed in detail. Estimates are given for the effects to be expected from unnatural parity exchange.     

Investigation of the effect of nucleus charge and atomic electron distributions on the processes of polarized bremsstrahlung of electrons in crystals

The process of polarized bremsstrahlung of electrons in crystals has been theoretically investigated with application of the new method taking into account the screening of the Coulomb nucleus field by atomic electrons. Real changes in the cross sections of both polarized and unpolarized bremsstrahlung and the degrees of particle polarization in a silicon crystal are obtained.     

Left-right asymmetry in Compton scattering on polarized electrons

In Compton scattering on polarized electrons a left-right asymmetry of the order 10⁻³ has been observed which must be attributed to higher-order corrections of the scattering amplitude. This effect might provide a test of quantum electrodynamics.     

Elastic scattering of electrons by atomic hydrogen at intermediate energies

The improved second Born computational method of Das has been used in computing the differential cross section for the elastic scattering of electrons by atomic hydrogen at intermediate energies (in the range 20–50eV). The results show that the method of Das works nicely down to energies of 20 eV.     

Magnetic neutrino scattering on atomic electrons revisited

We reexamine the role of electron binding effects in the inelastic neutrino–atom scattering induced by the neutrino magnetic moment. The differential cross section of the process is presented as a sum of the longitudinal and transverse components, according to whether the force that the neutrino magnetic moment exerts on electrons is parallel or perpendicular to momentum transfer. The atomic electrons are treated nonrelativistically. On this basis, the recent theoretical predictions concerning the magnetic neutrino-impact ionization of atoms are critically discussed. Numerical calculations are performed for ionization of a hydrogenlike Ge⁺³¹ ion by neutrino impact.     

Absolute differential bremsstrahlung cross section for the scattering of 0.6-keV electrons by xenon atoms

The spectral distribution of the absolute differential cross section for total bremsstrahlung, including ordinary and polarization, for the scattering of 0.6-keV electrons from free xenon atoms has been measured. The bremsstrahlung photons have been detected at an angle of 97° with respect to the electron motion direction. The investigations have been carried out in the ultrasoft x-ray spectral region 60–240 eV. The results are compared with the total cross sections for bremsstrahlung calculated in several approximations for the scattering of 5-and 25-keV electrons by Xe atoms. Both the value and the spectral distribution of the experimental absolute cross sections are most satisfactorily reproduced by the calculations in the distorted partial wave approximation.     

Photon antibunching upon scattering by an atomic Bose-Einstein condensate

Antibunching of photodetections from different modes is shown to arise when two quantized light modes are scattered by an atomic Bose-Einstein condensate. This effect appears because of the uncertainty in the position of the condensate wave function relative to the optical lattice formed by the light beams. It is shown how the information contained in the history of photodetections leads to a spatial localization of the condensate wave function.     

Capture of polarized electrons into excited atomic states in grazing scattering from a magnetized Ni(110) surface

The spin polarization of electrons captured into excited atomic levels of atoms during the scattering of fast ions from a magnetized Ni(110) surface under a grazing angle of incidence is deduced from the polarization of the fluorescence light. In our studies we have investigated the dependence of the spin polarization on projectile velocity and angle of incidence and observed generally small polarizations for captured electrons.     

Elastic scattering of electrons by the metastable 2s state of atomic hydrogen

A two-potential approach is used to study the elastic scattering of electrons by the metastable hydrogen atom. The results or differential and total cross sections are presented at 200 and 400 eV energies and compared with the available calculations. Also a comparison between elastic scattering from 2s and 1s states of hydrogen is made.     

Study of Compton scattering of gamma rays from atomic electrons

In the present work, measurements are made on the intensity and angular distribution of Compton scattered gamma rays of energy 279 keV from K-shell electrons of tin at scattering angles ranging from 30° to 150° and also determined the K-shell to free electron differential collision, absorption and scattering cross section ratio. For this purpose, two NaI(Tl) scintillation detectors working in coincidence with 30 nsec resolving time are used to record the events. The experimental results are compared with the available experimental and theoretical data.     

Weak and magnetic inelastic scattering of antineutrinos on atomic electrons

Neutrino scattering on electrons is considered as a tool for laboratory searches for the neutrino magnetic moment. Inelastic $\bar \nu _e e^ - $ scattering on electrons bound in the germanium (Z=32) and iodine (Z=53) atoms is studied for antineutrinos generated in a nuclear reactor core and in ⁹⁰Sr-⁹⁰Y and ¹⁴⁷Pm artificial sources. On the basis of the relativistic Hartree-Fock-Dirac model, both the magnetic-and weak-scattering cross sections are calculated for the recoil electron energy range between 1 and 100 keV, where a higher sensitivity to the neutrino magnetic moment could be achieved. Particular attention is paid to an approximate procedure that allows us to take into account the effects of atomic binding on the inelastic-scattering spectra in a simple way.