Measurements of Cu Atoms Diffusion Coefficients in He and Ne - Optimalisation of a Novel Method

A novel method based on two-pulse excitation of a hollow cathode discharge to determine metal atoms diffusion coefficients in noble gases was tested in Cu-He and Cu-Ne systems. The excitation conditions such as time duration of the discharge current pulses and configurations of the hollow cathode discharge were checked. Measurements carried out over the wide range gas pressures allowed obtaining the Cu atoms time-decay curves from which the diffusion coefficients were calculated. The values for Cu atom diffusion coefficients of 570 and 310 cm$\text{}^{2}$ s$\text{}^{-1}$ mbar in He and Ne, respectively were in a good agreement with earlier reported data achieved by using the absorption spectroscopy method. The diffusion coefficient of Cu in $\text{}^{3}$He, the lighter isotope of helium, was also found to be 670 cm$\text{}^{2}$ s$\text{}^{-1}$ mbar that agreed well with the kinetic theory of gases. To authors believe this value was not reported previously.