van der Waals interaction of an atom with the internal surface of a hollow submicrometer-size cylinder

We analyze the van der Waals interaction of an atom with the internal surface of a metal or dielectric submicrometer-sized cylinder and derive closed analytical equations for the van der Waals surface potential and force in the electrostatic approximation. We show that for a concave cylindrical surface the van der Waals potential energy can be up to four times larger than for a flat surface. This result is qualitatively explained by a reduction in the effective distance between the atom and the concave surface compared to that for a flat surface. We also evaluate the shape of an atomic beam propagating inside a hollow dielectric submicrometer-sized cylinder and we propose a scheme that will enable a precise measurement of the van der Waals constant C-3.