Optimizing area-backlighter performance in a difficult geometry

It is relatively easy to predict backlighter performance when few beams intercept a simple flat target and backlight an optically thin object. However, when faced with a thick target, noncooperating geometry, and multiple objects in the path of the laser beams, it becomes a challenge to find the optimum arrangement to satisfy all these conditions. On Omega, we came up with a unique solution, using more than one coaxial foil to optimize, not only the pointing and focusing, but also the uniformity and flux of x rays on the target using as many of the laser beams as possible. We will describe, the method used, the geometry used, and compare the prediction and the measurement. (C) 2003 American Institute of Physics.