Factors Affecting Particle Flow In Gravity-Driven Dense Granular-flow Target

The Accelerator Driven Subcritical System(ADS)is mainly composed of high current proton accelerator,high-power spallation target and subcritical reactor.The core component of ADS is the spallation target.The dense particle flow target is a new type of spallation target to meet the ultra high beam power of the ADS system.In recent years,the ADS spallation target team of the Institute of modern physics has proposed a Dense Granular-flow Target(DGT),which is driven by gravity.The core principle of the concept is to use dense granular flow as heat exchanger of target materials and target materials.DGT well avoids the disadvantages of flow instability in Heavy Liquid Metal(HLM)target,material corrosion and chemical toxicity leakage of HLM.It combines the advantages of solid targets and liquid targets,therefore DGT is the best choice for effective disposal of nuclear waste in the future.In the process of studying liquid heavy metal(HLM)target and DGT,people realized that the flow of target material and free surface play a very important role in the safe operation of ADS.This paper studies the influence of the structural parameters of gravity-driven dense particle flow targets on particle flow.In the experiment of cylindrical funnel target particle flow,the factors affecting the flow rate were compared under large openings and small open bottom funnels.Experiments indicate that the undulatory behavior of the free surface of the particle directly below the beam tube is stable.In the slant grain flow target experiment,the effect of the skew angle and the width of the chute opening on the particle flow was studied.The above experiment was simulated by discrete element method.The simulation results were in good agreement with the experimental results.The entire study makes sense for the design of gravity driven dense particle flow targets.