As far as I understand, there is no theory of sonoluminescence, and therefore there is no theory of bubble fusion. But such a theory must exist. Let's solve this problem together. In my opinion, the main thing here is the correct formulation of the problem. So, I dare to assume that we only need to find a solution (wave function) for a one-dimensional Schrodinger equation with a peridic potential, the period of which oscillates along the measurement line. In other words, we need to formulate the quantum mechanics of a charged particle in the field of a chain of nuclei along which a sound wave moves. I suppose first the potential can be simplified to a stationary wave consisting of the sum over all n expressions
V(x) = \delta(x - n(a\cos(Kx) + a))
where K is the wave vector of the sound wave and where a is average length between adjacent nuclei.
I will be glad if you start brainstorming this problem.