Effects of a liquid lithium curtain as the first wall in a fusion reactor plasma

This paper explores the effect of a liquid lithium curtain on fusion reactor plasma, such curtain is utilized as the first wall for the engineering outline design of the Fusion Experimental Breeder （FEB-E）. The relationships between the surface temperature of a liquid lithium curtain and the effective plasma charge, fuel dilution and fusion power production have been derived. Results indicate that under normal operation, the evaporation of liquid lithium does not seriously affect the effective plasma charge, but effects on fuel dilution and fusion power are more sensitive. As an example, it has investigated the relationships between the liquid lithium curtain flow velocity and the rise of surface temperature based on operation scenario II of the FEB-E design with reversed shear configuration and high power density. Results show that even if the liquid lithium curtain flow velocity is as low as 0.5 m/s, the effects of evaporation from the liquid lithium curtain on plasma are negligible. In the present design, the sputtering of liquid lithium curtain and the particle removal effects of the divertor are not yet considered in detail. Further studies are in progress, and in this work implication of lithium erosion and divertor physics on fusion reactor operation are discussed.[第一段]     

液态锂回路的净化及在线检测系统

介绍了液态锂回路中的净化及在线检测装置。该装置采用了冷阱法和热阱法,使回路中产生的C、 O、N 和氢同位素等杂质降至10wppm 以下。目前,已经利用四电极测电阻法测量了放锂前后的电阻随温度的变化曲线,再经过多项式拟合,计算得到了纯锂的电阻率随温度变化的函数。     

氢化锂中氢行为的第一性原理研究

采用基于密度泛函理论的第一性原理,对氢化锂中间隙氢离子的形成以及迁移行为进行了研究,结果表明间隙氢离子沿[1 1 1]方向迁移势垒最小,迁移到最近邻间隙和次近邻间隙时由其近邻氢离子主导的可能性更大,室温下间隙氢离子可自发迁移到最近邻间隙和第三近邻间隙.氢离子迁移到次近邻间隙和第四近邻间隙形成Frenkel缺陷的可能性最大,是形成Frenkel缺陷最可能的两个位置.     

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在对国内外液态锂回路研究综述的基础上,重点介绍了四川大学流动液态锂回路的研究进展。为开展等离子体与流动自由液态锂表面相互作用的研究而设计了该回路,其目标是：(1)获得稳定、均匀的流动自由液态锂表面;(2)研究等离子体辐照下液态锂的蒸发、溅射以及氢、氢同位素和氦在液态锂中的滞留行为;(3)研究等离子体辐照下液态锂与结构材料的相容性。系统包括液态锂循环部分和直线高密度等离子体发生装置。     

原子吸收光谱法测定铝锂合金中锂

本文研究了用原子吸收光谱法在笑气－乙炔火焰中测定铝锂合金中锂的最佳条件。其电离干扰可通过加进钾进盐来控制。应用本法测定合金中 锂的含量，获得了满意结果。     

近化学计量比双掺铁锰铌酸锂晶体紫外光致吸收特性的研究

研究了不同锂含量的双掺铁锰铌酸锂晶体的紫外光致吸收特性,结果表明,同成分晶体的紫外光致吸收系数较低,随着锂含量的增加,晶体的紫外光致吸收系数逐渐增大,当晶体中的锂含量达到49.57mol%附近时,紫外光致吸收系数达到最大值4.20 cm-1,进一步增加晶体中的锂含量,饱和光致吸收系数开始下降。在此基础上,提出了近化学计量比双掺铁锰铌酸锂晶体的双色非挥发全息存储的三中心模型,即随着晶体锂含量的增加,双掺铁锰晶体的光折变中心除了Fe2+/Fe3+,Mn2+/Mn3+外,还将增加双极化子/小极化子中心。     

EAST液态锂限制器分配盒参数对锂流动性影响

为考察溢流孔结构几何参数及壁面电导率对液态锂流动的影响,通过数值模拟方法对不同尺寸、形状及壁面电导率的溢流孔中液态锂的流动进行了数值模拟。结果表明：溢流孔的截面宽度越小,其出口的速度分布越均匀,速度峰值也越小,但溢流孔进出口之间的压力降会显著增加;且随着壁面电导率增大,MHD压降也随之增大。对于圆形及椭圆形截面的溢流孔,其出口的速度分布远比矩形溢流孔均匀。另外,关于限制器热平衡的计算有助于保证限制器的安全稳定运行。结果对分配盒几何参数的设计、电磁泵及冷却系统的设计具有重要的指导意义。     

纳米碳管的电化学贮锂性能

用透射电镜、高分辨透射电镜、X射线衍射和拉曼光谱表征了用催化热解法制备的纳米碳管的结构,研究了纳米碳管的电化学嵌脱锂性能。以纳米级铁粉为催化剂热解乙炔气得到的纳米碳管石墨化程度较低,结构中存在褶皱的石墨层、乱层石墨和微孔等缺陷,具有国交高的贮锂容量,初始容量为640mAh/g,但循环稳定性较差。而以纳米级氧化铁粉为催化剂热解乙烯得到的纳米碳管结构比较规则,循环稳定性较好,但贮锂容量较低,初始容量为282mAh/g。讨论了纳米碳管的结构对其温度特性和不同电流密度下的充放电容易的影响。     

Differential and Integral Cross Sections for Electron Impact Excitation of Lithium

The differential and integral cross sections for electron impact excitation of lithium from the ground state 1s22s to excited states 1s22p, 1s23l （l=s, p, d） and 1s24l （l=s, p, d, f）at incident energies ranging from 5 eV to 25 eV are calculated by using a full relativistic distorted wave method. The target state wavefunctions are calculated by using the Grasp92 code. The continuum orbitals are computed in the distorted-wave approximation, in which the direct and exchange potentials among all the electrons are included. A part of the cross sections are compared with the available experimental data and with the previous theoretical values. It is found that, for the integral cross sections, the present calculations are in good agreement with the time-independent distorted wave method calculation, for differential cross sections, our results agree with the experimental data very well.     

锂铌比对铪铁铌酸锂晶体全息存储性能的影响

以掺杂4mol%Hf4+的LiNbO3:Fe:Hf系列晶体([Li]/[Nb]比变化)为研究对象,研究了系列晶体的可见吸收光谱,在632.8nm的写入光下晶体的衍射效率、灵敏度和抗光散射能力在不同[Li]/[Nb]下的变化规律.研究发现Hf4+的浓度达到阈值浓度后,随着[Li]/[Nb]比的增大,晶体的可见吸收边会发生红移,而且晶格中[Fe2+]/[Fe3+]也会增加,这就导致随着[Li]/[Nb]比的增加,样品的衍射效率逐渐减小,写入时间缩短,灵敏度增大.同时,在晶体中,随着[Li]/[Nb]的增大,陷阱中心Fe2Li+数量增大会使得晶体抗光散射能力减弱.