Reflection of Radiation from a finite number of Equally Spaced Parallel Planes

Equations are derived for the fractions of the incident energy which are absorbed, reflected and transmitted by $n+1\mathrm{}$ equally spaced parallel planes, taking account of all possible internal reflection, in terms of the corresponding fractions for a single plane, $a$, $r$ and $t$ respectively. When $a$ and $r$ are very small, as in the case of x-rays incident on a crystal surface, they may be computed from measurements of the reflected fraction $R_N$ for $N$ large, and of the transmitted fraction $T_n$, for $n$ small.