Radiation reaction is related to Compton scattering. In Compton scattering, the interaction is between one electron and one photon producing one photon at a new

Radiation reaction is related to Compton scattering. In Compton scattering, the interaction is between one electron and one photon producing one photon at a new energy, with the electron changing energy. Non-linear Compton is one electron interacting with many photons to produce an electron and a high energy photon. Radiation reaction is essentially one electron scattering off many photons many times, producing many high energy photons. The paper itself is about the first observation of radiation reaction, there is work showing electrons losing energy in non-linear Compton scattering from the 1990s.