Buffer-gas loading of atoms and molecules into a magnetic trap

We describe a method for loading paramagnetic atoms or molecules into a magnetic trap. A ³He buffer gas is employed to thermalize atoms or molecules to a temperature of approximately 240 mK, lower than the depth of the trap. A model is described that indicates an initial loading density of approximately 10¹³ cm^-3. Once loading has taken place the buffer gas is removed by cryopumping. Evaporative cooling can then be applied to further lower the temperature and increase the density of the trapped sample.