Magnetic resonance imaging of fluid motion associated with electrodeposition processes

This paper describes an investigation of convection associated with electrodeposition processes using nuclear magnetic resonance (NMR) imaging. A convection of ZnSO₄ solution was generated at a Rayleigh number of 3.4×10¹¹ in an electrolytic bath which had a pair of horizontal zinc electrodes. Stejskal-Tanner plots of the fluid were measured with q gradients up to 1.1×10² mm^-1. Probability density functions (average propagators) of the displacement of fluid in the q gradient interval Δ=45 ms were obtained by Fourier transform of the Stejskal-Tanner plots. In the z direction, the bandwidths of the average propagators with and without convection were 8.5±1.3×10^-2 mm and 4.1±0.3×10^-2 mm, respectively. Maps of x, y, and z components of the flow velocity were calculated from phase maps. The bandwidth of the average propagator obtained from the flow velocity map was 4.4±0.6×10^-2 mm. These methods enable noninvasive and quantitative evaluation of transport phenomena by convection in electrodeposition processes.