English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We investigate the 2nd order process of two photons being emitted by ahigh-energy electron dressed in the strong background electric field foundbetween the planes in a crystal. The strong crystalline field combined withultra relativistic electrons is one of very few cases where the Schwinger fieldcan be experimentally achieved in the electron's rest frame. The radiationbeing emitted, the so-called channeling radiation, is a well studiedphenomenon. However only the first order diagram corresponding to emission of asingle photon has been studied so far. We elaborate on how the 2 photonemission process should be understood in terms of a two-step versus a one-stepprocess, i.e., if one can consider one photon being emitted after the other, orif there is also a contribution where the two photons are emitted'simultaneously'. From the calculated full probability we see that the two-stepcontribution is simply the product of probabilities for single photon emissionwhile the additional one-step terms are, mainly, interferences due to severalpossible intermediate virtual states. These terms can contribute significantlywhen the crystal is thin. Therefore, in addition, we see how one can, for athick crystal, calculate multiple photon emissions quickly by neglecting theone-step terms, which represents a solution of the problem of quantum radiationreaction in a crystal beyond the usually applied constant field approximation.We explicitly calculate an example of 180 GeV electrons in a thin Siliconcrystal and argue why it is, for experimental reasons, more feasible to see theone-step contribution in a crystal experiment than in a laser experiment.

Investigation of two photon emission in strong field QED using channeling in a crystal