Pressure ionization in laser-fusion target simulation

Accurate simulation of high density target implosion requires material properties (ionization, pressure, energy, opacity and transport coefficients) at densities where bound electrons are significantly perturbed by neighboring atoms. In modern laser-fusion simulation codes, this data is supplied by tables and/or calculated from a Stromgren model for ionization equilibrium. Improvements have been made in the Stromgren average-atom model which aim at assuring thermodynamic consistency and obtaining better agreement with more elaborate calculations. Arbitrary degeneracy is allowed for the free electrons. Consistent Coulomb contributions to pressure and continuum lowering are obtained. A new pressure ionization scheme merges bound electrons into the continuum as a smooth function of density and the corresponding contribution to pressure is calculated. Results are shown for aluminum.     

Thermonuclear gain of ICF targets with direct heating of ignitor

As the way of decreasing of the driver energy which is needed for ignition of the LCF targets, the conception of separation of the process of compression of the main mass of the fuel and the process of heating of the ignitor is suggested. Thermonuclear gain of the target with direct heating of the ignitor is calculated. It's shown that using the target with direct heating of the ignitor may lead to considerable decreasing of the driver energy: in (10–20) times for breakeven, and in (5–10) times for thermonuclear gain of 100–300 in comparison with the traditional conception of simultaneous compression and heating of the ICF target.     

Numerical design of a two-cascade cylindrical microtarget for shock-free compression

We present the numerical design of a two-cascade target. The desired target design is intended to provide a shock-free compression of the central DT core, where the fusion reactions take place. We obtain the formula for the energy deposition into each cascade internal layer for both known and unknown energy depositions into the external target layer. The two-cascade target design helps to increase the energy deposition into the DT layer and therefore decrease the energy required for the target ignition.     

Thermonuclear fusion in a strong laser field

Thermonuclear fusion induced by the irradiation of solid deuterated cluster targets and foils with fields of strong femtosecond and picosecond laser pulses is discussed. The thermonuclear-fusion process D(d, n)³He in a collision of two deuterons at an energy of 50 to 100 keV in a deuterium cluster target irradiated with a strong laser pulse is discussed. A theory of thermonuclear fusion proceeding upon the irradiation of clusters formed by deuterium iodide (DI) molecules with the field of a superintense femtosecond laser pulse is developed. This theory is based on an above-barrier process in which the sequential multiple inner ionization of atomic ions within a cluster is accompanied by field-induced outer ionization. The yield of neutrons from thermonuclear fusion in a deuteron-deuteron collision after the completion of a laser pulse is calculated. The yield of neutrons is determined for the thermonuclear-fusion reaction proceeding in the interaction of an intense picosecond laser pulse with thin TiD₂ foils. A multiple ionization of titanium atoms at the front edge of the laser pulse is considered. The heating of free electron occurs in induced inverse bremsstrahlung in the process of electron scattering on multiply charged titanium ions. The yield of alpha particles in the thermonuclear-fusion reaction involving protons and ¹¹B nuclei that is induced in microdrops by a strong laser field is determined. Experimental data on laser-induced thermonuclear fusion are discussed.     

Thermonuclear Instabilities and Fueling in a Tokamak Reactor

The problem of fueling is of primary importance in the conceptual design of a fusion reactor. We consider a possible mechanism of supplying fresh fuel from a cold-plasma layer at the surface of the plasma. The existence of an energetic component of ions, viz, the alpha particles, may excite unstable collective oscillations of the plasma (called the thermonuclear instabilities). Such instabilities could give rise to microscopic processes which, in principle, would allow influx of fresh fuel while helping efflux of reaction products. A three-regime model is used to understand the nature of such fueling mechanisms and the possibility of using a cold-plasma layer as a surface fueling source.     

Compression of two-cascade liners with an internal capillary discharge stage

It is demonstrated that columns of dense high-temperature plasma with various elemental compositions can be obtained when two-stage liners with an internal capillary discharge stage are compressed by current pulses from high-current generators. We also show that high-power pulses of K-line x-rays can be obtained and a homogeneous column of iron-containing plasma can be produced with near-optimal parameters in regard to creating a collisionally pumped 3p–3s x-ray laser based on neonlike iron. Institute of Strong-Current Electronics, Siberian Branch of the Russian Academy of Sciences. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 33–39, December, 1995.     

二级级联式室内可见光通信光学接收天线设计

针对室内可见光通信系统的传统光学接收天线无法同时满足高增益和大视场的问题, 设计了一种二级级联式光学天线. 通过分析信噪比、通信速率与接收天线视场角的关系, 发现视场角为40°–60°的光学天线最适用于室内可见光通信系统. 通过光学仿真软件TracePro的模拟及计算, 给出了所设计的二级级联式光学天线的增益随信号光入射角的变化关系. 结果表明, 相较于传统接收天线, 二级级联式光学天线具有更好的光学性能, 视场角为菲涅耳透镜单独接收时的4 倍. 利用Matlab对二级级联式光学天线竖直向上时的接收功率分布进行仿真, 结果显示探测器接收到的信号功率提升效果明显, 平均值较直接探测时增大了7 dBm, 进一步证实该二级级联式光学天线适用于室内可见光通信系统.     

压缩氘氚球的热核燃烧特性研究

本文利用LARED-S程序模拟了等密度和等压力条件下压缩氘氚球的热核反应燃烧过程.对于等密度模型,模拟了两个具体算例,与国外计算结果进行了比较,验证了程序的可靠性.对于等压力模型,利用数值模拟给出了热核反应燃烧与压缩氘氚球初始状态之间的关系曲线,分析发现,氘氚装量、压力和主燃料密度的增加有利于提高热核反应放能和燃耗,中心热斑的温度和面密度分别达到70—80 MK和3—4 kg·m^-2时热核反应才有显著的放能,提高主燃料密度,可以适当放宽对中心热斑的点火要求.最后对实际点火靶进行了数值模拟并且与等压力模拟计算结果进行了比较分析.     

激光核聚变诊断设备双光束交汇瞄准技术研究

 针对惯性约束激光核聚变诊断设备的精确安装瞄准问题,提出一种新的基于双光束交汇瞄准系统。瞄准指示光学系统采用里斯特显微物镜结构,物像距为180mm,放大倍率为10倍,数值孔径为0.25。机械结构设计采用二维指向可调、沿瞄准指示光学系统光轴可以移动的三维调整机构。系统整体占用空间锥角为28°,小于设计要求极限30°。分析了系统的瞄准误差,结果表明该系统的瞄准精度可达到25μm。该系统瞄准精度有望在激光核聚变靶室得到广泛应用。     

原子物理在受控核聚变中的应用

本文简介受控热核反应过程中遇到的许多原子物理问题,对于这些问题的了解和深入研究将有助于人类更早、更有效地控制热核反应. Many atomic physics processes in controlled thermonuclear fusion reactor areintroduced.The knowledge and detail study of these processes are very useful for mankind to controlthermonuclear fusion earlier and more efficiently.     

压缩氘氚球的热核燃烧特性研究

本文利用LARED-S程序模拟了等密度和等压力条件下压缩氘氚球的热核反应燃烧过程.对于等密度模型,模拟了两个具体算例,与国外计算结果进行了比较,验证了程序的可靠性.对于等压力模型,利用数值模拟给出了热核反应燃烧与压缩氘氚球初始状态之间的关系曲线,分析发现,氘氚装量、压力和主燃料密度的增加有利于提高热核反应放能和燃耗,中心热斑的温度和面密度分别达到70—80 MK和3—4 kg·m^-2时热核反应才有显著的放能,提高主燃料密度,可以适当放宽对中心热斑的点火要求.最后对实际点火靶进行了数值模拟并且与等压力模拟计算结果进行了比较分析. 关键词： 压缩氘氚球 等密度模型 等压力模型 热核反应聚变     

Heavy ion inertial fusion: Initial survey of target gain versus ion-beam parameters

Inertial-fusion targets have been designed for use with heavy-ion accelerators as drivers in fusion energy power plants. We have made an initial survey of target gain versus beam energy, power, focal radius, and ion range. This provides input for understanding the trade-offs among accelerator designs.     

Theoretical research on enhancement of gain for Ni-like Ag 13.9nm x-ray laser using a new two-layer target

For experiments such as on Ni-like Ag x-ray laser, driven by 1\omega laser, the gain region is only several~nm depth near the target surface, this paper proposes a new two-layer target, in which a thin layer (several nm depth) of silver is plated on the surface of some other materials. Furthermore, the Ni-like Ag 13.9~nm x-ray laser produced by three new kinds of two-layer target with CH, Al and Ge as foundation, was theoretically studied.     

Helium-3 as a Perspective Fuel for Power Generation through Aneutronic Thermonuclear Fusion

Physics of Atomic Nuclei - The aneutronic D3–He (deuterium–helium-3) fuel cycle is considered as a viable alternative to D–T (deuterium–tritium) fusion since it is...     

非Maxwell分布下平均热核反应率的计算

研究氘氚（DT）服从不同的速度分布函数时平均热核反应率的计算,当T服从Maxwell分布,D服从Maxwell分布、单能分布、一类特殊的非Maxwell分布时,用Monte Carlo方法（蒙卡方法）和直接积分两种方法同时计算DT的平均热核反应率,并验证蒙卡方法的正确性.利用蒙卡方法计算非Maxwell分布时的DT平均热核反应率,与Maxwell分布下的结果有较大的差别,说明在类似的情况下如果采用热动平衡下的平均热核反应率会引入较大的误差,相关认识可供非平衡效应研究参考.     

国际热核实验反应堆(ITER)计划与未来核聚变能源

能源短缺和环境恶化是人类社会面临的共同挑战.由于资源丰富、环境友好和零碳排放,核聚变能源是未来的理想能源.上世纪90年代以来,磁约束核聚变研究取得重大进展,以建造国际热核实验反应堆（ITER）为标志,聚变能源开发进入工程实施阶段,如果ITER计划取得预期成果,有望在本世纪中叶实现核聚变能源商用化.     

速度分群情况下氘氚热核反应率的模拟与分析

研究两种原子核粒子参与反应的热核聚变,假定一种原子核粒子处于热动平衡状态,对另一种原子核粒子速度分布进行分群,推导分群热核反应率以及平均热核反应率,编制相应计算程序;以氘氚热核聚变反应为例计算分群热核反应率和相应的平均热核反应率,并与直接积分结果进行对比;同时,细致研究平均热核反应率与速度分群数目的关系.