Applicability analysis of diffusion approach for calculation of radiativecharacteristics of the high pressure gas discharge

An analysis of the diffusion approach applicability for the radiation transfer calculations in the high pressure gas discharge has been carried out. It was shown that the diffusion approximation led to asymptotically correct results for the cases of optically thin and optically thick plasma columns. In the case of intermediate values of optical thickness the distinction between exact and diffusion approaches did not exceed 20 %.