Role of momentum and velocity for radiating electrons

Abstract

This version is available at https://strathprints.strath.ac.uk/55486/ Strathprints is designed to allow users to access the research output of the University of Strathclyde. Unless otherwise explicitly stated on the manuscript, Copyright © and Moral Rights for the papers on this site are retained by the individual authors and/or other copyright owners. Please check the manuscript for details of any other licences that may have been applied. You may not engage in further distribution of the material for any profitmaking activities or any commercial gain. You may freely distribute both the url (https://strathprints.strath.ac.uk/) and the content of this paper for research or private study, educational, or not-for-profit purposes without prior permission or charge.Any correspondence concerning this service should be sent to the Strathprints administrator: strathprints@strath.ac.ukThe Strathprints institutional repository (https://strathprints.strath.ac.uk) is a digital archive of University of Strathclyde research outputs. It has been developed to disseminate open access research outputs, expose data about those outputs, and enable the management and persistent access to Strathclyde's intellectual output. Radiation reaction remains one of the most fascinating open questions in electrodynamics. The development of multi-petawatt laser facilities capable of reaching extreme intensities has leant this topic a new urgency, and it is now more important than ever to properly understand it. Two models of radiation reaction, due to Landau and Lifshitz and to Sokolov, have gained prominence, but there has been little work exploring the relation between the two. We show that in the Sokolov theory electromagnetic fields induce a Lorentz transformation between momentum and velocity, which eliminates some of the counterintuitive results of Landau-Lifshitz. In particular, the Lorentz boost in a constant electric field causes the particle to lose electrostatic potential energy more rapidly than it otherwise would, explaining the long-standing mystery of how an electron can radiate while experience no radiation reaction force. These ideas are illustrated in examples of relevance to astrophysics and laser-particle interactions, where radiation reaction effects are particularly prominent.

From quantum to classical modeling of radiation reaction: A focus on stochasticity effects

“…These developments have motivated various theoretical works devoted to the treatment of radiation reaction in both classical electrodynamics [20][21][22][23][24][25][26], and QED [27][28][29][30][31][32] (see also Ref. [3] for a review).…”

“…Kinetic plasma simulations have demonstrated that it can alter the physical nature of radiationdominated relativistic current sheets at ultra-high magnetization [17]. Its importance was also demonstrated for the interpretation and modeling of gamma-ray flares in the Crab-Nebulae [18] and of pulsars [19].These developments have motivated various theoretical works devoted to the treatment of radiation reaction in both classical electrodynamics [20][21][22][23][24][25][26], and QED [27][28][29][30][31][32] (see also Ref.[3] for a review). Radiation reaction, treated either using a radiation friction force in the framework of classical electrodynamics or a Monte-Carlo procedure to account for the quantum process of high-energy photon emission, has also recently been implemented in various kinetic simulation codes, in particular Particle-In-Cell (PIC) codes [4][5][6][33][34][35].…”

Relativistic Doppler-boosted γ-rays in High Fields

“…However it is well known that the so-called Lorentz-Abraham-Dirac (LAD) equation suffers from anomalies, leading to unphysical solutions. Detailed discussions comparing models are given in references 47 , 48 . In order to account for the RR force, we consider the Landau Lifshitz equation 34 .…”

Self-force on a charged particle in an external scalar field

“…Until recently, this has been a matter of purely theoretical concern, as under most experimental conditions the self-force represented a negligible correction to any applied forces. Rapid advances in laser technology have changed this situation [2], and the prospect of experimentally accessing regimes where the self-force is not only non-negligible, but actually dominates the dynamics, has rejuvinated interest in understanding its fundamental properties [3][4][5][6][7][8][9][10].…”

“…In the Sokolov model of the self-force[26], the particle can only lose energy in an electrostatic field, regardless of whether or not it is ultra-relativistic[7].…”