  Elastically bent single-crystal Laue case diffraction crystals provide
interesting new opportunities for imaging and spectroscopy applications. The
diffraction properties are well understood, however, the ability to easily
model the diffracted beams hinders assessment of the focal, phase and energy
dispersive properties needed for many applications. This work begins to collect
the elements needed to ray trace diffracted beams within bent Laue crystals for
the purpose of incorporation into other powerful ray tracing applications such
as SHADOW. Specifically, we address the condition in a bent Laue crystal where
a cylindrically bent Laue crystal will focus all the polychromatic diffracted
beams at a single location when a specific asymmetry angle condition is met for
a target x-ray energy - the so-called "magic condition". The focal size of the
beam can be minimized, but this condition also results in excellent
energy-dispersive properties. The conceptual and mathematical aspects of this
interesting focusing and energy dispersive phenomenon is discussed.
