Radiation Reaction Features in Collective QED Signatures

Signatures of collective QED driven behavior will be necessary to distinguish the unique aspects of the QED plasma regime. Recent publications [1,2,3] suggest that a laser frequency upshift in a QED cascade, analogous to an upshift in an ionizing plasma, could serve as such a signature. However, this effect is heavily suppressed in the relativistic regime, and great care will need to be taken to ensure detectability. We extend previous work and explore other features of upshifts and other signatures which could arise in similar configurations.

[1] Qu, Kenan, Sebastian Meuren, and Nathaniel J. Fisch. "Signature of collective plasma effects in beam-driven qed cascades." Physical review letters 127.9 (2021): 095001.

[2] Qu, Kenan, Sebastian Meuren, and Nathaniel J. Fisch. "Collective plasma effects of electron–positron pairs in beam-driven QED cascades." Physics of Plasmas 29.4 (2022): 042117.

[3] Griffith, Alec, Kenan Qu, and Nathaniel J. Fisch. "Particle Deceleration for Collective QED Signatures." PoP Accepted; arXiv preprint arXiv:2204.06755 (2022).