While some francium atoms escape, most stay trapped:
As reported in the Canadian Journal of Physics (2017), laser-trapped francium atoms were irradiated with blue laser light, causing some of them to be photoionized (lose an electron) and lost from the francium trap. The probability of photoionization was in line with the general trend exhibited by the other alkali atoms. Photoionization losses from the laser trap are one of the most serious limitations for a trap-based tests of atomic parity violation, and the results of this experiment importantly support the feasibility of such experiments.