  Neutron stars lose the bulk of their rotational energy in the form of a
pulsar wind: an ultra-relativistic outflow of predominantly electrons and
positrons. This pulsar wind significantly impacts the environment and possible
binary companion of the neutron star, and studying the resultant pulsar wind
nebulae is critical for understanding the formation of neutron stars and
millisecond pulsars, the physics of the neutron star magnetosphere, the
acceleration of leptons up to PeV energies, and how these particles impact the
interstellar medium. With the SKA1 and the SKA2, it could be possible to study
literally hundreds of PWNe in detail, critical for understanding the many open
questions in the topics listed above.
