相关论文: On the polar cap cascade pair multiplicity of youn…
We study electron-positron pair production in polar caps of energetic pulsars to determine the maximum multiplicity of pair plasma a pulsar can produce under the most favorable conditions. This paper complements and updates our study of…
We discuss the creation of electron-positron cascades in the context of pulsar polar cap acceleration models and derive several useful analytic and semi-analytic results for the spatial extent and energy response of the cascade. Instead of…
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…
I argue that the problem of electromagnetically driven electron-positron cascades in magnetospheres of neutron stars must be addressed starting from first principles. I describe a general numerical algorithm for doing self-consistent…
We present numerical simulations of the electron-positron plasma creation process in a simple neutron star magnetosphere. We have developed a set of cascade `kernels', which represent the endpoint of the pair cascades resulting from…
Pulsar magnetospheres are thought to be filled with electron-positron plasma generated in pair cascades. The driving mechanism of these cascades is the emission of gamma-ray photons and their conversion into pairs via Quantum…
We present numerical simulations of electron-positron pair cascades in the magnetospheres of magnetic neutron stars for a wide range of surface fields (B_p = 10^{12}--10^{15} G), rotation periods (0.1--10 s), and field geometries. This has…
Using an analytic, axisymmetric approach that includes general relativity, coupled to a condition for pair production deduced from simulations, we derive general results about the spatial distribution of pair-producing field lines over the…
We report on the first self-consistent multidimensional particle-in-cell numerical simulations of non-homogeneous pair discharges in polar caps of rotation-powered pulsars. By introducing strong inhomogeneities in the initial plasma…
We explore the role of complex multipolar magnetic fields in determining physical processes near the surface of rotation powered pulsars. We model the actual magnetic field as the sum of global dipolar and star-centered multipolar fields.…
Electron-positron pair cascades developed in the extreme electromagnetic fields of neutron star polar caps are considered a key source of magnetospheric plasma in these objects. We use a simplified model that maps the Quantum…
Recent advances in numerical algorithms and computational power have enabled first-principles simulations of pulsar magnetospheres using Particle-in-Cell (PIC) techniques. These ab-initio simulations seem to indicate that pair creation…
In the present work one- and two-photon pair production in a subcritical magnetic field have been considered. Two-photon production has been studied in the resonant case, when the cross section considerably increases compared to the…
In this paper we study the possibility of efficient pair production in a pulsar's magnetosphere. It has been shown that by means of the relativistic centrifugal force the electrostatic field exponentially amplifies. As a result the field…
Pulsar wind nebulae (PWNe) dominate the galactic gamma-ray sky at very high energies and they are major contributors to the leptonic cosmic ray flux. However, the question of whether or not pulsars also accelerate ions to comparable…
We present a global kinetic plasma simulation of an axisymmetric pulsar magnetosphere with self-consistent $e^\pm$ pair production. We use the particle-in-cell method and log-spherical coordinates with a grid size $4096\times 4096$. This…
We investigate a pair creation cascade in the magnetosphere of a rapidly rotating neutron star. We solve the set of the Poisson equation for the electro-static potential and the Boltzmann equations for electrons, positrons, and gamma-ray…
It is shown that for moderately hot polar caps (with effective temperature of $\sim 10^6$ K), the efficiency of polar gap acceleration is lower compared to the case in which the polar caps are relatively cool and inverse Compton scattering…
Using a simplified model of cascade pair creation over pulsar polar caps presented in two previous papers, we investigate the expected gamma-ray output from pulsars' low altitude particle acceleration and pair creation regions. We divide…
It was recently proposed that the electric field oscillation as a result of self-consistent $e^{\pm}$ pair production may be the source of coherent radio emission from pulsars. Direct Particle-in-Cell (PIC) simulations of this process have…