Optimizing capture efficiency in a magneto-optical trap

We have studied the user of vapor-cell magneto-optical traps for the collection and investigation of trace elements of radioactive isotopes. The fundamental processes governing efficient collection of neutral isotopes in a trap have been identified and integrated into a model that accurately describes the collection process. The model has been verified experimentally; a 6% capture efficiency has been demonstrated for stable Cs isotopes and we predict a simple change in trapping cell geometry will allow a 50% capture efficiency. This paper discussed the issues involved in efficient capture, such as the trapping laser properties and wall-coatings. It describes a new cell design for efficient capture and discusses current work towards trapping small numbers of ²²¹Fr (T_1/2 equals 4.8 minutes) atoms.