Self-diffusion and inter-diffusion coefficients of liquid lithium isotopes

Diffusion processes in a liquid mixture of lithium isotopes

“…Since increases with T , it follows that a temperature rise is expected to produce a strong diminution of N /N . This result is in full agreement with the corresponding diminution of K m , as deduced earlier from our interpretation of diffusivity data [1,2] .…”

“…However, such a discussion will not be given here, because we will not use the asymptotic behaviour to determine G(u) . The presence of a factor u 4 exp( u 2 ), which is found to weight G(u) in the integral expressing the current density of diffusing particles [1], shows that the knowledge of G(u) for u is of little interest. Roughly, we can say that the values of u contributing to the integral lie in the interval 0 u 3 , which approximately defines the width of the peak corresponding to the above factor.…”

“…The corresponding form of equation (4) becomes a generalization of equation (42) of the quoted reference [1], so that, putting…”

“…Since, however, the solution of equation (5) represents a tremendous analytical problem, the above procedure becomes necessary. In the quoted paper [1] it was adopted in connection with a trial function of the form…”

“…Since no phonons exist for K > K m , it follows that the processes referring to case 1 are confined to values of K falling in the range between 0 and K m . The theory of these processes [1] concerns the scattering of a particle by a system carrying longitudinal waves, under the assumption that all the particles interact through a Fourier transformable potential (r) . The probability rate is found to be proportional to K 2 , which in the above range is approximately V 0 2 .…”