Optical trapping of cold fermionic potassium for collisional studies - art. no. 052709

We report on trapping of fermionic K-40 atoms in a red-detuned standing-wav e optical trap, loaded from a magneto-optical trap. Typically, unpolarized samples of 10(6) atoms are loaded at a density of 10(12) cm(-3) and a tempe rature of 65 muK, and trapped for more than 1 s. The optical trap appears t o be the proper environment for performing collisional measurements on the cold atomic sample. In particular, we measure the spherically averaged elas tic collision rate by detecting the rethermalization following an intention al parametric heating of the atoms. We also measure spherically averaged in elastic two-body collision rates for atoms in the ground hyperfine states, through detection of trap losses.