Predictive modeling of the deuterium gas puffing effect on impurity and heat flux compression for the HL-2M divertor by SOLPS

•Deuterium gas puffing is proposed on HL-2M lower-single null (LSN) divertor, using SOLPS with 4MW energy flowing into the srape-off layer (SOL). The divertor detachment is very sensitive to the gas puffing location and rate. Moreover, it is easy to achieve detachment when puffing deuterium near the divertor region with a deuterium gas puffing rate of 1022 s−1.•A reasonable deuterium gas puffing is an effective solution to induce intrinsic impurity ions to accumulate in the divertor region, which has a beneficial impact on compressing impurity level and enhancing divertor detachment simultaneously.•The effective ion charge Zeff reduces resulting from the impurity flow pattern modification induced by the deuterium gas puffing and pumping. The impurities retain in the ionization region and even flow downstream when they finish ionization before reaching the stagnation point with gas puffing.