The effect of trap anharmonicity on the critical temperature for Bose-Einstein condensation

The anharmonicity of a magnetic atomic trap at long distances from its center (forty times the radius of the first atomic orbit along the elongated axis, i.e. hundreds of microns) is shown to increase up to 45 % the temperature for Bose-Einstein condensation. This effect is perhaps small in the traditional traps, but should certainly be taken into account in magnetic microtraps, which characteristic dimensions are of order 1 mm.