Magnetic trapping of copper and silver using buffer gas loading

Atomic silver and coppper are magnetically trapped using buffer gas loading. Copper (Cu) is trapped in the $4s\;^2{\rm S}_{1/2}$, $m_j=1/2$ state with lifetimes as long as 8s. Silver (Ag) is trapped in the $5s\;^2{\rm S}_{1/2}$, $m_j=1/2$ state with lifetimes as long as 2.3 s. Lifetimes are limited by collisions with background $^3$He. Inelastic Zeeman state-changing collisions are observed between Ag and $^3$He. The ratio of transport to inelastic cross-sections for Ag-$^3$He is found to be $2.9\pm 0.2\times 10^6$ at 410 mK in a 4.0 T anti-Helmholtz trapping field. The spin relaxation cross-section is observed to vary with temperature as $T^{5.8\pm 0.4}$ between 300 mK and 630 mK and vary with trap magnetic field detph as $B^{-0.9\pm 0.2}$ between 2 T and 4 T. The transport to inelastic cross-section ratio for Cu-$^3$He collisions is found to be $8.0\pm 0.3\times 10^{6}$ at 400 mK. Comparison is made to alkali-noble gas theory, showing that additional considerations are necessary beyond the typical treatment restricted to the $s$ valence electron.