Recombination contributions to the anisotropic emission from a laser produced copper plasma

We report here the results of a study of polarisation resolved emission from a laser produced copper plasma. We found that in the case of such a plasma, the degree of polarisation was higher for a background pressure of 1 × 10⁻² mbar than for 1 × 10⁻⁵ mbar, but the time evolution of this parameter was similar for both. Optical diagnostics revealed differences in the electron temperature and density also. A collisional radiative model was then employed to calculate the time varying rates of both radiative and 3-body recombination. We found that the rates were strongly polarisation and time dependent for our plasma and thus we suggest that both 3-body and radiative recombination play a role in the ultimate optical anisotropy of the plasma. (paper)