Introduction Comparison of equivalent Helium and Deuterium discharges can supply important information for a deeper understanding of impurity sources and radiation characteristics in the divertor region. In a He plasma, a significantly different impurity release and its radiation behaviour is expected, which has a strong impact on divertor physics, modifying the character of detachment and density limits. When compared to Deuterium plasma the L-mode density limit in Helium is approximately twice as high (1.4 times the Greenwald limit).