G. Thorkildsen et al., Approximate solution of the Takagi-Taupin equations for a semi-infinite crystal in the three-beam Laue-Laue case, ACT CRYST A, 57, 2001, pp. 389-394
An analytical approximate solution of the Takagi-Taupin equations for a sym
metrical three-beam Laue-Laue case in a perfect non-absorbing semi-infinite
crystal slab has been obtained. The expression, a second-order expansion,
is valid for situations where the effective crystal thickness does not exce
ed half the actual extinction length and it is shown to be in perfect agree
ment with the full numerical solution of the fundamental equations.