Ionization in a Bose-Einstein condensate of metastable Helium: a quantitative monitoring tool

Abstract

Residual ionization in a BEC of 2 3 S1 metastable Helium (He*), can be used to monitor in real time the evolution of a single sample of condensate. We use this method, combined to Time Of Flight measurements, to study the decay of the condensate. It has also allowed us to measure 2-body and 3-body ionizing collisions rate constants. This method should allow for the study of the growth of a condensate, in particular in the hydrodynamic regime. We point out the importance of quantum depletion in He* BEC's.