Collisional dephasing of the Na13d13ftransition using the Ramsey method of separated rf fields

Abstract
The collisional dephasing of the Na 13d13f transition by Ne and CO has been investigated using the Ramsey method of separated radio-frequency fields. Upper limits for the dephasing cross sections are determined which are far smaller than the geometric size of the excited Na atoms. This leads to the conclusion that the separation of the potential cruves of the Na 13dX and 13fX states is nearly constant as a function of internuclear separation.