The instability of gravity-capillary waves in the strong electric and magnetic fields on a neutron-star surface

Abstract

We investigate the amplification of gravity-capillary waves on the surface of a liquid metal, immersed in a strong magnetic field, by an external electric field. The implication for the physical situation characteristic for the surface of a neutron star is discussed. In particular, we consider in this paper the magnetic polar-cap region of a neutron star, with the following parameters: the surface magnetic field ≌(1–2)×1012 G; the mass density of matter (iron) in the very surface layer ≌103 g cm−3; the rotationally-induced electric field near the surface ≌106–107 CGSE, to be assumed. It is shown that the instability of gravity-capillary waves develops when the temperature of the liquid phase of matter ≲105 K and the binding energy of ions within the surface ≌0.1–0.2 KeV. The growth time (≈10−9 s) and the characteristic length-scale (≈10−4 cm) of the instability are estimated. We point out the possibility that this instability can initiate an intensive generation of charged particles by the neutron stars (radio pulsars).