Computational Design of Infrared Enhanced Layering of ICF Capsules

A computational model is presented for infrared heating of frozen hydrogen layers in cryogenic ICF capsules. The model contains linked ray trace and heat conduction programs. The conduction part of the model has been validated with a cryogenic hohlraum experiment without infrared irradiation. The complete model has been used to design and analyze experiments on infrared layering of D₂ in a hohlraum. The modeling provides an understanding of how to control the long scale length ice thickness perturbations by varying the infrared power balance and beam pointing. Based on the confidence developed in the model by comparison to experiment, design calculations are presented for IR layering systems for ICF ignition targets.