  Similar to the terrestrial collision accelerators of electron-antielectron,
another kind of accelerator is above a positively or negatively charged pulsar
polar cap. In the case of pulsars with magnetic axis parallel (anti-parallel)
to rotational axis, relativistic antielectron (electron) with Lorentz factor
about 10^6 hit the electrons in the polar caps. These scenarios are
investigated both for pulsars being bare strange stars and for pulsars being
neutron stars. Such a study may be valuable to differentiate neutron stars and
bare strange stars observationally.
