A permanent magnet trap for buffer gas cooled atoms and molecules

Cold molecules are set to provide a wealth of new science compared to their atomic counterparts [1]. Here we want to present preliminary results for cooling and trapping atoms/molecules in a permanent magnetic trap. By replacing the conventional buffer gas cell [2] with an arrangement of permanent magnets, we will be able to trap a fraction of the molecules right where they are cooled. For this purpose we have designed a quadrupole trap using NdFeB magnets, which has a trap depth of 0.4 K for molecules with a magnetic moment of 1 $\mu_{\mathrm{B}}$. Cold helium gas is pulsed into the trap region by a solenoid valve and the atoms/molecules are subsequently ablated into this and cooled via elastic collisions, leaving a fraction of them trapped. This new set-up is currently being tested with lithium atoms as they are easier to make. After having optimised the trapping and detection processes, we will use the same trap for YbF molecules. \\[4pt] [1] L.D. Carr, D. DeMille, R.V. Krems and J. Ye, \textit{New J. Phys}. 11, 055049 (2009)\\[0pt] [2] S. M. Skoff, R. J. Hendricks, C. D. J. Sinclair, J. J. Hudson, D. M. Segal, B. E. Sauer, E. A. Hinds and M. R. Tarbutt, \textit{Phys. Rev. A} 83, 023418 (2011)