Photons

Section author: Axel Huebl

Module author: Heiko Burau

Radiation reaction and (hard) photons: why and when are they needed. Models we implemented ([Gonoskov] and [Furry]) and verified:

Would be great to add your Diploma Thesis [Burau2016] talk with pictures and comments here.

Please add notes and warnings on the models’ assumptions for an easy guiding on their usage :)

Note

Assumptions in Furry-picture and Volkov-States: classical em wave part and QED “pertubation”. EM fields on grid (Synchrotron) and density modulations (Bremsstrahlung) need to be locally constant compared to radiated coherence interval (“constant-crossed-field approximation”).

Attention

Bremsstrahlung: The individual electron direction and gamma emission are not correlated. (momentum is microscopically / per e- not conserved, only collectively.)

Attention

“Soft” photons from low energy electrons will get underestimated in intensity below a threshold of … . Their energy is still always conserved until cutoff (defined in …).

Note

An electron can only emit a photon with identical weighting. Otherwise, the statistical variation of their energy loss would be weighting dependent (note that the average energy loss is unaffected by that).

References

Gonoskov

A. Gonoskov, S. Bastrakov, E. Efimenko, A. Ilderton, M. Marklund, I. Meyerov, A. Muraviev, A. Sergeev, I. Surmin, E. Wallin. Extended particle-in-cell schemes for physics in ultrastrong laser fields: Review and developments, Physical Review E 92, 023305 (2015), https://dx.doi.org/10.1103/PhysRevE.92.023305

Furry

W. Furry. On bound states and scattering in positron theory, Physical Review 81, 115 (1951), https://doi.org/10.1103/PhysRev.81.115

Burau2016

H. Burau. Entwicklung und Überprüfung eines Photonenmodells für die Abstrahlung durch hochenergetische Elektronen (German), Diploma Thesis at TU Dresden & Helmholtz-Zentrum Dresden - Rossendorf for the German Degree “Diplom-Physiker” (2016), https://doi.org/10.5281/zenodo.192116