Prediction of superionic state in LiH_(2) at conditions enroute to nuclear fusion  

作　　者：李福德 王豪 李津龙 耿华运 Fude Li;Hao Wang;Jinlong Li;Huayun Geng(National Key Laboratory of Shock Wave and Detonation Physics,Institute of Fluid Physics,CAEP,Mianyang 621900,China;HEDPS,Center for Applied Physics and Technology,and College of Engineering,Peking University,Beijing 100871,China)

机构地区：[1]National Key Laboratory of Shock Wave and Detonation Physics,Institute of Fluid Physics,CAEP,Mianyang 621900,China [2]HEDPS,Center for Applied Physics and Technology,and College of Engineering,Peking University,Beijing 100871,China

出　　处：《Chinese Physics B》2023年第10期566-571,共6页中国物理B（英文版）

基　　金：Project supported by the National Key Research and Development Program of China(Grant No.2021YFB3802300);the National Natural Science Foundation of China(Grant No.11672274);the NSAF(Grant No.U1730248)。

摘　　要：Hydrogen and lithium,along with their compounds,are crucial materials for nuclear fusion research.High-pressure studies have revealed intricate structural transitions in all these materials.However,research on lithium hydrides beyond LiH has mostly focused on the low-temperature regime.Here,we use density functional theory and ab initio molecular dynamics simulations to investigate the behavior of LiH_(2),a hydrogen-rich compound,near its melting point.Our study is particularly relevant to the low-pressure region of the compression pathway of lithium hydrides toward fusion.We discovered a premelting superionic phase transition in LiH_(2)that has significant implications for its mass transportation,elastic properties,and sound velocity.The theoretical boundary for the superionic transition and melting temperature was then determined.In contrast,we also found that the primary compound of lithium hydrides,LiH,does not exhibit a superionic transition.These findings have important implications for optimizing the compression path to achieve the ignition condition in inertial confinement fusion research,especially when lithium tritium-deuteride(LiTD)is used as the fuel.

关 键 词：lithium polyhydrides high pressure and high temperature superionic state phase transition 

分 类 号：TL62[核科学技术—核技术及应用]