Accuracy validation of flux limited diffusion models for calculating alphaparticle transport in ICF plasmas

Within the framework of a one dimensional study, the accuracy is examined o f two kinds of flux limited diffusion model: one is the artificially flux l imited model developed by Corman and the other is based on the Levermore-Po mraning theory, for evaluating the alpha particle heating rate in laser imp loded DT targets. It is found that the former model cannot correctly evalua te the ignition condition and the gain since it significantly underestimate s the heating rate in the region where alpha particles are born. Contrary t o this: in the latter model, which can estimate well the profile of the alp ha particle heating rate, not only the time integrated burn properties but also the fuel evolution in space and time are in good agreement with result s obtained on the basis of accurate transport calculations.