0000000000889811
AUTHOR
Vladimir A. Yerokhin
Spin-orbit interaction in bremsstrahlung and its effect on the electron motion in a strong Coulomb field
Linear polarization of bremsstrahlung x rays produced in collisions of longitudinally polarized 2.1-MeV electrons with gold atoms was studied using the Compton scattering technique. We observed that the angle of x-ray polarization is strongly correlated with the incoming electron polarization. This correlation reveals the dominance of the spin-orbit interaction in bremsstrahlung and indicates a striking effect of the electron spin on the electron motion in a strong Coulomb field. The results confirm the validity of the theoretical predictions in a computationally challenging energy regime.
Atomic physics studies at the gamma factory at CERN
The Gamma Factory initiative proposes to develop novel research tools at CERN by producing, accelerating and storing highly relativistic, partially stripped ion beams in the SPS and LHC storage rings. By exciting the electronic degrees of freedom of the stored ions with lasers, high-energy narrow-band photon beams will be produced by properly collimating the secondary radiation that is peaked in the direction of ions' propagation. Their intensities, up to $10^{17}$ photons per second, will be several orders of magnitude higher than those of the presently operating light sources in the particularly interesting $\gamma$--ray energy domain reaching up to 400 MeV. This article reviews opportuni…
Determination of the electron’s mass from g -factor experiments on 12 C 5+ and 16 O 7+
Abstract We present a derivation of the electron’s mass from our experiment on the electronic g factor in 12C5+ and 16O7+ together with the most recent quantum electrodynamical predictions. The value obtained from 12C5+ is me=0.0005485799093(3) u, that from oxygen is me=0.0005485799092(5) u. Both values agree with the currently accepted one within 1.5 standard deviations but are four respectively two-and-a-half times more precise. The contributions to the uncertainties of our values and perspectives for the determination of the fine-structure constant α by an experiment on the bound-electron g factor are discussed.
Strong effect of the electron spin on bremsstrahlung observed in the relativistic regime
We have studied bremsstrahlung produced by polarized 2.1 MeV electrons colliding with a thin gold target. We have observed a strong correlation between the orientation of the electron spin and the angle of x-ray linear polarization at the x-ray high energy tip region. This indicates a dominance of the spin-orbit interaction in bremsstrahlung.
Compton transmission polarimeter for a very precise polarization measurement within a wide range of electron currents
For new experiments with polarized electron and positron beams the precise and quick measurement of the beam polarization is required. The relative electron polarization has been monitored on-line using a compact transmission Compton polarimeter for a wide range of average electron currents up to 100/μA and electron beam energy of 3.5 MeV. The asymmetry induced by the beam polarization can be monitored precisely with ΔA/A < 0.2 %. Even small relative variations of the beam polarization during a beam time may be detected using this polarimeter, such as an increase ~ 1 % and subsequent decrease of the beam polarization.