玻璃微球内氘结晶行为研究  

Crystallization behaviors of deuterium in glass microsphere

作　　者：尹剑[1] 陈绍华[1] 温成伟[1] 夏立东[1] 李海容[1] 黄鑫[1] 余铭铭[1] 梁建华[1] 彭述明[1] 

机构地区：[1]中国工程物理研究院核物理与化学研究所,绵阳621900

出　　处：《物理学报》2015年第1期186-192,共7页Acta Physica Sinica

基　　金：国家重大专项资助的课题~~

摘　　要：为研制出满足惯性约束聚变(ICF)实验的氘氚(DT)冷冻靶,需要控制DT结晶生长过程,实现DT单晶生长,由此减少影响冰层均匀化及聚变实验的晶体缺陷.本文运用晶体生长形态动力学理论建立了密排六方晶体(hcp)单晶生长模型,实验中通过对靶室进行±3 m K精确控温,采用可见光背光成像技术在线表征了低温下玻璃微球内氘(D2)的结晶生长过程,结果表明:在20—100 Pa低温氦气导热环境下,通过缓慢降温可显著降低氘晶体生长过程中形成的缺陷;当降温速率达到2 m K/min时,观测到了氘燃料的两种单晶生长过程,实验具有可重复性;建立的hcp单晶生长理论模型与实验结果符合,并与美国利弗莫尔国家实验室(LLNL)的DT单晶生长过程进行了对比,提出了冷冻靶内D2/DT燃料的单晶生长方法.To develop deuterium-tritium （DT） cryogenic targets that meet the inertial confinement fusion （ICF） experiment requirements, the DT crystal seeding growth process needs to be controlled to obtain single crystalline DT-ice, thus reducing the crystal defects formed during crystal growth and improving ice-layering. In this paper, the close-packed hexagonal （hcp） single crystal growth mode has been established through kinetic theory of crystal growth morphology. Experimentally, the target chamber temperature is controlled to within ±3 mK and the deuterium （D2） crystal growth process can be observed by backlit shadowgraphy. Results show that slow cooling can reduce the crystal defects sig- nificantly at the 20-100 Pa conducting helium pressure. When the cooling rate reaches 2 mK/min, two single crystal growth modes are observed with good reproducibility. Experimental results conform with the proposed hcp single crys- tal growth model. Compared with the results from Lawrence Livermore National Laboratory （LLNL）, the methods of D2/DT single crystal growth in the cryogenic target are proposed.

关 键 词：惯性约束聚变 背光成像 降温速率 单晶生长 

分 类 号：TL632[核科学技术—核技术及应用]