Bremsstrahlung polarization correlations and their application for polarimetry of electron beams

Abstract

SynopsisThe correlation between electron spin and photon linear polarization in atomic-field bremsstrahlung was measured with a polarized electron beam. The angle of photon polarization and the photon emission intensity were found to be correlated with the spin orientation. These effects are interpreted in terms of spin-orbit interaction. They lead to a new technique of electron beam polarimetry.

Radiative-electron-capture-to-continuum cusp inU88++N2collisions and the high-energy endpoint of electron-nucleus bremsstrahlung

“…The screening effects lead to a cross section at the high-energy endpoint of the bremsstrahlung spectrum, which is reduced compared to the point-Coulomb results, thus preventing clean experimental conditions for electron-nucleus bremsstrahlung in pure Coulomb fields [14,19]. Recent measurements performed by Tashenov et al [23,24] and by Märtin et al [25] used an approach similar to that of Nakel et al and studied the effects of a polarized incoming electron on the polarization of the emitted photon, but no coincidence with the scattered electron was applied.…”

Polarization of atomic bremsstrahlung in coincidence studies

“…Most of the studies of atomic bremsstrahlung in the past were dedicated to the properties of the emitted photons, while the scattered electrons remained unobserved. In these works, the angular distribution of the emitted radiation [1][2][3][4][5][6] and its polarization [7][8][9] was investigated. Due to experimental limitations, less attention was paid to setups where the emitted photons and the scattered electrons are observed in coincidence.…”

Linear polarization of x-ray transitions due to dielectronic recombination in highly charged ions

“…[55][56][57] and the x-ray em ission asym m etry [58,59] identified strong contributions o f the Breit interaction, especially in heavy gold and uranium ions, the C om pton linear polarim etry gives a higher sensitivity to this intrinsically relativistic effect, even in the m uch lighter xenon ions, where this effect is less pronounced [12]. M oreover, as was dem onstrated in the earlier Com pton polarim etry work, the sensitivity o f this m ethod can be further significantly im proved [26,42,60,61], opening a large exploration space, in particular allow ing one to access the quantum electrodynam ics corrections o f the generalized Breit interaction [62,63].…”

“…A pplication o f the C om pton polarim etry technique provides a significant advantage over the Bragg polarim etry technique, previously used at EBITs [17,48,[72][73][74], by m easuring, in addition to the degree o f polarization, the angle o f polariza tion [42,61 ] and by being effective in a broader range o f ener gies [41,75], O ur im plem entation o f the C om pton polarim etry is also significantly more accurate [26,41,42,60,61,76] than a sim ilar techniques used in nuclear physics [77][78][79][80], The high polarim etry accuracy allows deep probes o f the electronim pact ionization and excitation [48,[72][73][74]81,82], resonant excitation [83], and radiative recom bination [26,51,84] by revealing the alignm ent [51,84,85] …”