Only Experiment Will Tell

What about,

$n=\cfrac{a_\psi}{a_\psi-d}$  and

$n=\cfrac{\psi_{n\,i}}{\psi_{n\,r}}$ ??

A new expression for $n$ is derived in the post "Success Is In The Way You Handle The Question"

In this perspective,

$\psi_r=h.f_r=\psi_o+x_rF=2\pi a_{\psi\,r}mc$

$\psi\propto a_\psi$

and obviously,

$a_\psi-d=a_{\psi\,r}$

we still have a valid and consistent expression for $n$.  As far as this view is concerned, $\psi$ deformed uniformly into a smaller sphere of new radius $a_{\psi\,r}$.

So, X-ray can be made more penetrating by passing through a prism.  Only experiment will tell.