  A spatial structure of the zone blocked by the dipolar electric field of a
Rydberg atom is calculated taking into account a possibility of excitation to
the states with neighboring values of the principal quantum number. As a
result, it was found that the blocked zone represents a number of co-centric
spherical shells rather than a solid ball, and the respective pair correlation
function should have additional maxima at small interparticle distances.

Atomic Physics;Optics