Electrostatic trapping of metastable NH molecules

Research paper by Steven Hoekstra, Markus Metsala, Peter C. Zieger, Ludwig Scharfenberg, Joop J. Gilijamse, Gerard Meijer, Sebastiaan Y. T. van de Meerakker

Indexed on: 07 Jan '08Published on: 07 Jan '08Published in: Physics - Atomic Physics


We report on the Stark deceleration and electrostatic trapping of $^{14}$NH ($a ^1\Delta$) radicals. In the trap, the molecules are excited on the spin-forbidden $A ^3\Pi \leftarrow a ^1\Delta$ transition and detected via their subsequent fluorescence to the $X ^3\Sigma^-$ ground state. The 1/e trapping time is 1.4 $\pm$ 0.1 s, from which a lower limit of 2.7 s for the radiative lifetime of the $a ^1\Delta, v=0,J=2$ state is deduced. The spectral profile of the molecules in the trapping field is measured to probe their spatial distribution. Electrostatic trapping of metastable NH followed by optical pumping of the trapped molecules to the electronic ground state is an important step towards accumulation of these radicals in a magnetic trap.