Model of pulsar pair cascades in non uniform electric fields: growth rate, density profile and screening time

Understand

Time-dependent cascades of electron-positron pairs are thought to be the main source of plasma in pulsar magnetospheres and a primary ingredient to explain the nature of pulsar radio emission, a longstanding open problem in high-energy astrophysics.

• During these cascades - positive feedback loops of gamma-ray photon emission, via curvature radiation by TeV electrons and positrons, and pair production -, the plasma self-consistently develops inductive waves that couple to electromagnetic modes capable of escaping the pulsar dense plasma.
• In this work, we present an analytical description of pair cascades relevant in pulsars, including their onset, exponential growth and saturation stages.
• We study this problem in the case of a background linear electric field, relevant in pulsar polar caps, and using an heuristic model of the pair production process.