Li Xiaodong, Wan Jiangfeng, Zhang Sheng, Lin Ping, Zhang Yanshi, Yang Guanghui, Wang Mengke, Duan Wenshan, Sun Jian'an, Yang Lei
College of Physics and Electronics Engineering and Joint Laboratory of Atomic and Molecular Physics of NWNU, Lanzhou, China.
Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China.
PLoS One. 2017 Nov 2;12(11):e0187435. doi: 10.1371/journal.pone.0187435. eCollection 2017.
A spallation target is one of the three core parts of the accelerator driven subcritical system (ADS), which has already been investigated for decades. Recently, a gravity-driven Dense Granular-flow Target (DGT) is proposed, which consists of a cylindrical hopper and an internal coaxial cylindrical beam pipe. The research on the flow rate and free surface are important for the design of the target whether in Heavy Liquid Metal (HLM) targets or the DGT. In this paper, the relations of flow rate and the geometry of the DGT are investigated. Simulations based on the discrete element method (DEM) implementing on Graphics Processing Units (GPUs) and experiments are both performed. It is found that the existence of an internal pipe doesn't influence the flow rate when the distance from the bottom of the pipe to orifice is large enough even in a larger system. Meanwhile, snapshots of the free surface formed just below the beam pipe are given. It is observed that the free surface is stable over time. The entire research is meaningful for the design of DGT.
散裂靶是加速器驱动次临界系统（ADS）的三个核心部件之一，对此已研究了数十年。最近，有人提出了一种重力驱动的致密颗粒流靶（DGT），它由一个圆柱形料斗和一个内部同轴圆柱形束流管道组成。无论是在重液金属（HLM）靶还是DGT中，对流速和自由表面的研究对于靶的设计都很重要。本文研究了DGT的流速与几何形状之间的关系。同时进行了基于图形处理器（GPU）上实现的离散元法（DEM）的模拟和实验。研究发现，即使在较大的系统中，当管道底部到孔口的距离足够大时，内部管道的存在不会影响流速。同时给出了束流管道正下方形成的自由表面的快照。观察到自由表面随时间是稳定的。整个研究对DGT的设计具有重要意义。
