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1.
Simulations of a double Z-pinch hohlraum, relevant to the high-yield inertial-confinement-fusion concept, predict that through geometry design the time-integrated P2 Legendre mode drive asymmetry can be systematically controlled from positive to negative coefficient values. Studying capsule elongation, recent experiments on Z confirm such control by varying the secondary hohlraum length. Since the experimental trend and optimum length are correctly modeled, confidence is gained in the simulation tools; the same tools predict capsule drive uniformity sufficient for high-yield fusion ignition.  相似文献   

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在4 MA以下电流驱动Z箍缩黑腔辐射特性和耦合效率研究牵引下,研制出了柱型动态黑腔。利用CHO低密度泡沫的自持能力,结合辅助夹具解决了泡沫柱的装配及定位问题。基于负载丝受小应变作用,丝阵和泡沫柱通过μm量级的自由滑动和转动,具备自动适应靶室环境变化能力。实验结果表明:研制出的动态黑腔在Angara-5-1装置环境中具有自动适应能力,各项参数满足物理实验的需求,获得的最高动力学黑腔X光辐射温度为62.7 eV,实验结果重复性优于91.5%。  相似文献   

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在4 MA以下电流驱动Z箍缩黑腔辐射特性和耦合效率研究牵引下,研制出了柱型动态黑腔。利用CHO低密度泡沫的自持能力,结合辅助夹具解决了泡沫柱的装配及定位问题。基于负载丝受小应变作用,丝阵和泡沫柱通过μm量级的自由滑动和转动,具备自动适应靶室环境变化能力。实验结果表明:研制出的动态黑腔在Angara-5-1装置环境中具有自动适应能力,各项参数满足物理实验的需求,获得的最高动力学黑腔X光辐射温度为62.7 eV,实验结果重复性优于91.5%。  相似文献   

4.
We demonstrate the hohlraum radiation temperature and symmetry required for ignition-scale inertial confinement fusion capsule implosions. Cryogenic gas-filled hohlraums with 2.2 mm-diameter capsules are heated with unprecedented laser energies of 1.2 MJ delivered by 192 ultraviolet laser beams on the National Ignition Facility. Laser backscatter measurements show that these hohlraums absorb 87% to 91% of the incident laser power resulting in peak radiation temperatures of T(RAD)=300 eV and a symmetric implosion to a 100 μm diameter hot core.  相似文献   

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The European Physical Journal D - We studied the directional dependency of electronic stopping power of swift light ions in nickel using real-time time-dependent density functional theory. We...  相似文献   

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Infinite conformal symmetry of critical fluctuations in two dimensions   总被引:3,自引:0,他引:3  
We study the massless quantum field theories describing the critical points in two dimensional statistical systems. These theories are invariant with respect to the infinite dimensional group of conformal (analytic) transformations. It is shown that the local fields forming the operator algebra can be classified according to the irreducible representations of the Virasoro algebra. Exactly solvable theories associated with degenerate representations are analized. In these theories the anomalous dimensions are known exactly and the correlation functions satisfy the system of linear differential equations.Professor A. B. Zamolodchikov was unable to attend the conference to present this invited paper personally.  相似文献   

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激光间接驱动惯性约束聚变实验中,黑腔内情况复杂,在激光烧蚀和辐射烧蚀等的驱动下,光斑区、冕区、纯辐射烧蚀区、射流区的多种等离子体以不同规律运动.发展了X光双能段窄能带的时间分辨成像方法,用以观测黑腔内多种等离子体的运动情况.在真空黑腔中观测到清晰的射流,分析了射流产生机制及其速度;在黑腔中充气,能有效消除射流和抑制冕区等离子体运动,但两种物质界面处可能会出现流体力学不稳定性等现象,分析了界面处的压力平衡关系和密度陡变情况.  相似文献   

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The two-point correlation functions of classical electromagnetic zero-point radiation fields are evaluated in four-vector notation. The manifestly Lorentz-covariant expressions are then shown to be invariant under scale transformations and under the conformal transformations of Bateman and Cunningham. As a preliminary to the electromagnetic work, analogous results are obtained for a scalar Gaussian random classical field with a Lorentz-invariant spectrum.  相似文献   

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《Nuclear Physics B》1996,466(3):444-462
We study the model of (2 + 1)-dimensional relativistic fermions in a random non-Abelian gauge potential at criticality. The exact solution shows that the operator expansion contains a conserved current — a generator of a continuous symmetry. The presence of this operator changes the operator product expansion and gives rise to logarithmic contributions to the correlation functions at the critical point. We calculate the distribution function of the local density of states in this model and find that it follows the famous log-normal law.  相似文献   

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Generalized expressions are obtained for the power of synchrotron radiation of both charged and uncharged systems with charge distribution having spherical symmetry. The distribution is considered arbitrary in the radial direction.Tomsk Polytechnic Institute. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 12–15, September, 1993.  相似文献   

16.
In dynamic force microscopy the cantilever of an atomic force microscope is vibrated at ultrasonic frequencies in the range of several 10 kHz up to several MHz while scanning a sample surface. The amplitude and phase of the cantilever vibration as well as the shift of the cantilever resonance frequencies provide information about local sample surface properties. In several operation modes of dynamic force microscopy, for example force modulation microscopy, tapping mode or atomic force acoustic microscopy, the sensor tip is in contact with the sample at least during a fraction of its vibration cycle. The periodic indentation of the tip with the sample surface generates ultrasonic waves. In this paper, the ultrasonic radiation of a vibrating cantilever into a sample and its contribution to the damping of the cantilever vibration are calculated. The theoretical results are compared to experiments.  相似文献   

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点火黑腔内环激光通道内靠近黑腔壁的区域是内环激光受激拉曼散射(SRS)背向散射产生与发展的主要区域。根据内环通道在该区域满足通道内外压力平衡和能量平衡,提出了间接驱动惯性约束聚变点火黑腔等离子体定标关系。该定标关系在一定程度上统筹考虑靶丸性能、激光器指标和激光等离子体相互作用(LPI)。在此基础上,根据靶丸抑制流体不稳定的需求,提出了一个350eV点火黑腔设计,该设计可以较好地抑制内环LPI的发展,并对激光器设计提出了更高的要求。  相似文献   

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It is shown here that real crystals besides their crystallographic symmetry (230 space groups) display another kind of symmetry called in this paper — the dynamic symmetry (1651 Shubnikov groups). The dynamic symmetry manifests itself during transformation by the crystal structure of quantities whose symmetry has two-color operations.An example is given of application of dynamic symmetry for interpretation of phenomenon of forbidden reflexions in an X-ray pattern of ethylidene-N, N′-diacetamide crystals.  相似文献   

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The exponential blueshift associated with the event horizon of a black hole makes conformal symmetry play a fundamental role in accounting for its thermal properties. Using a derivation based on two-point functions, we show that the full spectrum of thermal radiation of scalar particles by Kerr black holes can be explicitly derived on the basis of a conformal symmetry arising in the wave equation near the horizon. The simplicity of our approach emphasizes the depth of the connection between conformal symmetry and black hole radiance.  相似文献   

20.
We show that correlated dynamics and long time memory persist in self-organized criticality (SOC) systems even when forced away from the defined critical point that exists at vanishing drive strength. These temporal correlations are found for all levels of external forcing as long as the system is not overdriven. They arise from the same physical mechanism that produces the temporal correlations found at the vanishing drive limit, namely the memory of past events stored in the system profile. The existence of these correlations contradicts the notion that a SOC time series is simply a random superposition of events with sizes distributed as a power law, as has been suggested by previous studies.  相似文献   

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