Collimation of plasma-produced x-rays by spherical crystals: Ray-tracing simulations and experimental results

Ray-tracing simulations, validated by experimental results, demonstrate that high intensity collimated x-ray beams can be produced from an isotropic x-ray source. A spherically bent mica crystal was used to collimate and monochromatize x rays emitted by a femtosecond laser-produced plasma. The result is a short pulse x-ray beam with a high degree of collimation ~less than 1 mrad divergence!, good spectral resolution (10,Dl/l,10), and tunability over a wide spectral range. The role of the experimental parameters in the resulting beam divergence is thoroughly analyzed by ray-tracing modeling. These simulations are validated by test experiments. The ray-tracing calculations define a set of boundaries in the experimental parameters, which will guarantee the achievement of collimated beams better than 1 mrad in further experiments. © 1999 American Institute of Physics. @S0034-6748~99!01303-9#