[en] It poses increased challenge to develop a viable plasma-materials interface solution for next-step long pulse tokamaks, such as a Fusion Nuclear Science Facility (FNSF), which will have lower plasma density than ITER for high performance steady-state current drive and high duty cycle operation. An innovative divertor concept, named small angle slot (SAS), has been developed on the DIII-D tokamak facility at General Atomics to address the challenge of efficient divertor heat dispersal compatible with non-inductive current drive in future tokamaks. The goal of this advanced divertor solution is to optimize the geometry of the target and baffle for the control of neutrals to provide the most efficient and complete energy deposition possible. Modeling using a multidimensional boundary plasma-fluid and Monte-Carlo-neutral transport code package (SOLPS) shows that SAS leverages the strong synergistic effects of a critical small target angle and a gas-tight slot geometry to achieve strongly dissipative divertor plasmas over the entire divertor surface at relatively low main plasma densities. This provides a potential means for simultaneous control of heat flux and erosion at the material surface, which is mandatory for high-performance steady-state fusion plasmas.