Determining the clock frequency shift due to collisions in a 1-D optical lattice clock with 88Sr

We describe our experiment which evaluates frequency shifts due to collisions in a 1-D optical lattice clock with ⁸⁸Sr. The atoms in the lattice are probed on the ¹S₀-³P₀ transition which is highly forbidden but becomes weakly allowed by applying a static homogeneous magnetic field which mixes ³P₁ to the ³P₀ state. Using the method of interleaved stabilization, we have quantified the density dependent shift of the ⁸⁸Sr clock transition. By knowing the coefficient of the shift we can determine optimum conditions under which a 1-D lattice clock with ⁸⁸Sr can be operated with a fractional accuracy of 10^-16.