Numerical Modelings Of Snowflake Divertor In CFETR With SOLPS

China Fusion Engineering Test Reactor (CFETR) is now in conceptual design phase. CFETR is proposed as a good complement to ITER for demonstrating of fu-sion energy. Main goals are determined for fusion power:Pf=50 200 MW; duty cycle time≥0.3-0.5; and tritium breeding ratio～1.2.100 MW heat flux is conserva-tively assumed to flow into scrapped-off layer (SOL). Considering the smaller major radius R=5.7 m of CFETR compared with ITER, and also for exploring an effective way to manage heat exhaust in a future fusion reactor, other than the standard divertor, a snowflake divertor (SFD) is now proposed as an optional choice for CFETR. Snowflake divertor(SFD) has caused a wide concern due to its properties of significantly reducing heat flux on target plates. Compared to the standard divertor, it represents a broader flux expansion and a longer connection length to divertor plate. In our previous work , divertor geometry is preliminary designed under the consideration of compatibility of ITER-like and snowflake magnetic configuration.Most closely associated with the operating state of divertor plasma parameters is the the plasma density, as the density increases, the divertor will experience shealth limited,conduction limitide and detachment three operational state. In this thesis work, we used the method of gas puffing in the main chamber with deuterium to density scan in order to obtain the complete situation of snowflake divertor operation state with the density evolution, give proper operating range. On the other hand is considered an impurity radiation, based on experience in the design of ITER, without considering the tritium lag and other issues, CFC divertor itself sputtered C impurity radiation can provide enough heat to reduce peak divertor targets of load. In order to more efficiently carry out CFETR divertor design work, this paper still in C as an impurity radiation as a future filled with W divertor radiation impurities (such as N, Ne, Ar, etc.) in place, the results will also serve as the future of radiation impurities determination criteria required to achieve the effect. The current calculation in order to avoid a pneumatic position selection brings uncertainty calculations assume divertor targets material is introduced into the C natural impurities. Simulation results show that as the density increases, especially after the divertor completely detachment, C impurities more easily through the X point into the core, before C impurity in the core region and the proportion of scraping layers less than 1.5%. Therefore, due to the demand of impurities constraining performance, divertor able to run (in accordance with the desired operating range ITER) in some detachment, so the upper limit of gas puffing rate given.Based on SOLPS simulation, we obtained complete picture of CFETR snowflake divertor operational stateg as puffing rate increas, and due to the purpose of restrictions on engineering Target peak heat load and the C-discipline, given the current optimum operating range divertor gas puffing rate corresponding 1 sim3 times10023s-1. Within that, inborad divertor is in a partially detachment, and outboard divertor is conduction limited or partially detachment. Further optimization of the physical and engineering calculations are undergoing.