氘化钛阴极的制备

根据串列加速器中铯溅射负离子源（ＳｏｕｒｃｅｓｏｆＮｅｇａｔｉｖｅＩｏｎｓｂｙＣｅｓｉｕｍＳｐｕｔｔｅｒｉｎｇ,ＳＮＩＣＳ）产生负氘离子的要求,制备了一种氘化钛阴极。它由１个圆柱形的铜阴极心和填满其中心孔的氘化钛溅射靶构成,作为溅射靶材料的氘化钛通过高纯度钛粉与氘进行化学反应制得。钛粉在适当的温度下进行真空处理,从而获得良好的化学活性,很容易与氘化合生成氘钛原子比为１．５的氘化钛（ＴｉＤ１．５）。     

氘化聚乙烯靶的研制

文章介绍氘化聚乙烯靶的二种制备方法，即溶液蒸发和真空蒸发法。前者适用于制备厚的自支撑靶，而后者主要用来制作有衬薄靶。靶的厚度和均匀性分别用称重法和分光光度法测量。     

金属镱低压吸氘研究

在真空系统中的氘压低于0.1 MPa条件下研究了金属镱的吸氘性能,并对不同原子比的氘化物的物相进行了分析.在常压、300 ℃下,金属镱吸氘不明显;400 ℃时,金属镱经较长时间活化后吸附一定量的氘;500 ℃时,镱升华.400 ℃时的吸氘实验结果表明:从活化至开始吸氘直至吸附平衡需很长时间;氘/镱原子比的高低与吸氘时间有关,饱和吸氘时的原子比最大为2.00;金属镱为面心立方(fcc)结构,a0=0.549 2 nm.具有不同原子比的氘化镱的X射线衍射(XRD)分析结果显示:氘化镱有2种结构,即面心立方结构(a0=0.524 nm)和正交结构(a0=0.588 nm、b0=0.358 nm、c0=0.678 nm);金属镱吸氘后,立方结构氘化镱晶格常数及晶胞体积均发生收缩现象,收缩率分别约为4%和11%.正交结构氘化镱晶胞体积收缩约14%.     

中子粉末衍射方法在全氢氨基酸分子研究中的应用

研究氨基酸分子结构的传统方法为X射线衍射和氘化后中子衍射。本文应用X射线衍射、中子粉末衍射和拉曼散射研究丙氨酸和亮氨酸分子的结构。结合红外光谱技术,比较全氢、部分氘化和完全氘化的丙氨酸分子结构,发现这两种方法在氨基酸分子结构研究中的不足。同时,应用中子粉末衍射方法对亮氨酸分子进行直接测量,结果表明：中子粉末衍射方法可给出亮氨酸分子的精细结构。     

金属镱低压吸氘研究

在真空系统中的氘压低于0．1MPa条件下研究了金属镱的吸氘性能，并对不同原子比的氘化物的物相进行了分析。在常压、300℃下，金属镱吸氘不明显；400℃时，金属镱经较长时间活化后吸附一定量的氘；500℃时，镱升华。400℃时的吸氘实验结果表明：从活化至开始吸氘直至吸附平衡需很长时间；氘／镱原子比的高低与吸氘时间有关，饱和吸时的原子比最大为2．00；金属镱为面心立方（fcc）结构，a0=0.5492nm。具有不同原子比的氘化镱的X射线衍射（XRD）分析结果显示：氘化镱有2种结构，即面心立方结构（a0=0.524nm）和正交结构（a0=0.588nm、b0=0.358nm、c0=0.678nm）；金属镱吸氘后，立方结构氘化镱晶格常数及晶胞体积均发生收缩现象，收缩率分别约为4％和11％。正交结构氘化镱晶本积收缩约14％。     

氢/氘化钛热解吸的动力学同位素效应

在高真空金属系统上测定了氢化钛和氘化钛在恒容体系中、350~550℃温度下热解吸氢和氘的P-t曲线;应用反应速率分析方法计算了各自在不同温度下的反应速率常数,得到氢化钛和氘化钛热解吸的表观活化能分别为27.1±0.4和42.3±1.9 kJ/mol。氘化钛热解吸氘的表观活化能高于氢化钛热解吸氢的表观活化能,表现出显著的热解吸动力学同位素效应,表明氘化钛热解吸时需要更高的初始能量;同时也说明氘化钛在相同条件下比氢化钛更稳定。     

离子注入玻璃

离子注入和离子束分析技术在半导体和金属改性中已获得广泛应用,近年来又开始应用于绝缘体。在1981年第一届绝缘体辐照效应国际会议(REI-81)上,美国Sandia实验室Arnold和意大利Chinellato等发表离子注入玻璃效应的初步研究。Mazzoldi曾应用核反应分析对玻璃辐照效应进行了详细研究。 带电粒子辐照玻璃引起网状损伤并改变了表面化学成分。钠玻璃经离子注入后产生钠离子迁移,Na迁移有两种不同机构,在低质量离子辐照时以电子阻止本领为主,此时钠受到和     

15 MeV～3 GeV电子加速器90°方向光子源项研究

韧致辐射光子是电子加速器屏蔽设计中的重要源项。为研究90°方向光子源项特征以及靶体半径和厚度对90°方向光子源项的影响,采用蒙特卡罗程序MCNPX27对15 MeV～3 GeV电子束轰击铁靶后的辐射源项进行计算。分析了90°方向光子辐射剂量、光子能谱等源项随靶厚度和半径的变化。通过与0°方向光子源项以及靶体内级联电子沉积能量进行对比,进一步分析了90°方向的光子源项特点。结果表明,90°方向光子能量主要集中在10 MeV以内,光子能谱形状与入射电子能量关系较小。受级联电子在靶内能量沉积程度及靶体对光子自吸收的共同影响,靶体半径和厚度是影响90°方向光子源项的重要因素。在电子加速器的屏蔽设计中应考虑靶体尺寸差异所带来的影响,同时建议针对束流90°方向和0°方向光子源项的差异,对加速器辐射屏蔽和防护进行优化设计。     

LaNi_(4.9)Al_(0.1)D_x去氘化动力学性能的氚老化效应

测定了不同材料的LaNi4.9Al0.1Dx去氘化动力不数，评价了Chuan老化对LaNi4.9Al0.1Dx去氘化动力学性能的影响。研究结果表明，反应速率常数随老化时间的延长而降低；Chuan老化不改变LaNi4.9Al0.1Dx去氘化的反应级数；支氘化反应级数a（由氘压决定）和b（由氘浓度决定）分别为0．5和1；活化能随老化时间的延长而增加，老化1120d，速率常数降低了2个数量级，活化能约增加30％。     

氧化层对钛吸附与解吸氘的动力学影响研究(Ⅱ)--氧化层对氘化钛热解吸动力学的影响

测定了3种不同氧化层厚度的氘化钛在873～1073K范围内的热解吸反应速率常数,得到673K下氧化5、2h的氘化钛和未经氧化处理的氘化钛热解吸氘的活化能分别为(29.0±1.0)、(27.6±1.0)和(24.9±1.4)kJ/mol。实验表明:氘化钛表面氧化层具有阻氘性能,氘化钛表面氧化层越厚,表观活化能越大。     

T型半导体量子线的动态屏蔽效应

采用动态屏蔽库仑势计算了T型半导体量子线的载流子自能,讨论了电子、空穴的自能及其对量子线截面尺度的依赖关系。计算结果表明,准一维体系具有很强的量子限域效应,显著增强了载流子间的有效库仑作用。受电子间强烈散射的影响,动态屏蔽导致了电子能带重整化及寿命的很大变化。与准静态近似计算结果相比,动态屏蔽效应对空穴的影响较小。     

Electron Multiplication in Cavities

A computer program which simulates the multiplications of electrons in cavities using Monte Carlo techniques has been developed. This electron multiplication program has provided an understanding of the x-ray energy spectrum produced by cavities and of x-ray photographs taken of cavities at high fields. Also, this simulation has predicted two new effects: (1) an electron avalanche multiplication effect which is non-resonant in nature (as opposed to the well known resonant electron multi-pactoring), and (2) electrons produced in this way tend to form a low energy (on the order of 10 eV) electron cloud near the cavity major diameter.     

Maruhn–Greiner Maximum of Uranium Fission for Confirmation of Low Energy Nuclear Reactions LENR via a Compound Nucleus with Double Magic Numbers

One of the most convincing facts about LENR due to deuterons of very high concentration in host metals as palladium is the measurement of the large scale minimum of the reaction probability depending on the nucleon number A of generated elements at A = 153 where a local maximum was measured. This is similar to the fission of uranium at A = 119 where the local maximum follows from the Maruhn–Greiner theory if the splitting nuclei are excited to about MeV energy. The LENR generated elements can be documented any time after the reaction by SIMS or K-shell X-ray excitation to show the very unique distribution with the local maximum. An explanation is based on the strong Debye screening of the Maxwellian deuterons within the degenerate rigid electron background especially within the swimming electron layer at the metal surface or at interfaces. The deuterons behave like neutrals at distances of about 2 picometers. They may form clusters due to soft attraction in the range above thermal energy. Clusters of 10 pm diameter may react over long time probabilities (megaseconds) with Pd nuclei leading to a double magic number compound nucleus which splits like in fission to the A = 153 element distribution. An erratum to this article can be found at     

Electron- and photon-induced desorption

The process of electron and photon induced desorption as a quantum effect (that is, as opposed to thermal effects) has now been firmly established. Considerable data exists on electron induced desorption in the low energy range of approximately 0–200 eV. It now seems certain that these low energy electrons interaction directly with the adsorbed gas species and that desorption effects are fairly independent of the substrate material. Results from several laboratories showing the similarity of data for carbon monoxide adsorption and desorption on different metals will be discussed as a typical system. True photodesorption has now been established but is based on very much fewer experimental results. Our most recent data seem to indicate that the photodesorption process involves first absorption by the substrate with desorption occurring via a secondary process. Thus, the photodesorption process is very much substrate dependent. Recent results obtained on a number of different substrate materials will be discussed and the possible mechanism considered.     

Impact of nuclear irradiation on helium bubble nucleation at interfaces in liquid metals coupled to permeation through stainless steels

The impact of nucleating gas bubbles in the form of a dispersed gas phase on hydrogen isotope permeation at interfaces between liquid metals, like LLE, and structural materials, like stainless steel, has been studied. Liquid metal to structural material interfaces involving surfaces, may lower the nucleation barrier promoting bubble nucleation at active sites. Hence, hydrogen isotope absorption into gas bubbles modelling and control at interfaces may have a capital importance regarding design, operation and safety.He bubbles as a permeation barrier principle is analysed showing a significant impact on hydrogen isotope permeation, which may have a significant effect on liquid metal systems, e.g., tritium extraction systems. Liquid metals like LLE under nuclear irradiation in, e.g., breeding blankets of a nuclear fusion reactor would generate tritium which is to be extracted and recirculated as fuel. At the same time that tritium is bred, helium is also generated and may precipitate in the form of nano bubbles.Phenomena modelling is exposed and implemented in openFROM^® CFD tool for 0D to 3D simulations. Results for a 1D case show the impact of a He dispersed phase of nano bubbles on hydrogen isotopes permeation at an interface. In addition, a simple permeator simulation, consisting in a straight 3D pipe is exposed showing the effect of a He dispersed gas phase on hydrogen isotope permeation through different stainless steels. Results show the permeation reduction as a function of the interface area covered by He bubbles.Our work highlights the effect of gas bubble nucleation at interfaces and the importance of controlling these phenomena in nuclear technology applications.     

Cold fusion: What do we know? what do we think?

Summary Considering the experiments which have been listed as convincing in Fig. 1, two groups have provided evidence for the existence of an unidentified small heat source. The low level of heat that is produced in the Texas A&M and Stanford work, can most plausibly be explained by a chemical explanation. The absence of helium and neutrons is consistent with this explanation, however, the high tritium level observed by Texas A&M is not.In the dry cell tests two groups present good evidence for an unidentified small neutron source. The best guess for an explanation may be hot fusion cascade. In our opinion, there is really no convincing case yet for nuclear fusion, certainly not of any practical value, but there seems to be a real effect and it has to yet be identified.There are far more groups with good equipment who found no effect at all. There may be some possible reasons for that, but there is certainly no clear reason for it. We think that the evidence suggests that more work is appropriate. We think that funding should be commensurate with the understanding of this phenomenon and of its possible usefulness.     

Self-diffusion in pure metals

Measurements of the temperature, mass and pressure dependence of the self-diffusion coefficient have proved to be particularly valuable in determining the mechanism of diffusion. The interpretation of these data in terms of diffusion by monovacancies and divacancies has, in general, been successful and has provided information on the properties of these intrinsic defects. In the present review we first develop in some detail the equations that relate defect properties to measurable diffusion parameters for use in this and the following papers. Diffusion in selected pure metals is then reviewed. The potential errors inherent in relating high-temperature diffusion data over a limited temperature range to properties of monovacancies are demonstrated for a number of metals. The magnitude of the temperature dependence of defect properties is not well known, which increases our uncertainty in divacancy properties but has less effect on monovacancy properties deduced from tracer-diffusion measurements.     

Cyclotron instability in ogra

Conclusions The experimental results reported here indicate that a cyclotron instability can and does develop in Ogra. Furthermore, at the present time, as far as we know there is no other possible explanation for the anomalous magnitude and the dependence of electric field (at the cyclotron frequency) on plasma density observed experimentally. The presence of density waves with different phase velocities can cause electron heating and electron loss. In this regard, the fact that the electrons can interact with the electric waves seems to be indicated by experiments with an electron beam carried out by Yu. A. Kucheryaev and D. A. Panov [9]; these experiments indicate that an electron beam passing through a plasma along the magnetic field loses or gains energy by virtue of interaction with waves at the cyclotron frequencies corresponding to H ₂ ⁺ and H ₁ ⁺ ions.On the one hand, the effect of the cyclotron instability can cause ions to form bunches as a result of nonlinear effects, and these can lead to a more effective interaction, with the dissipation and exchange of energy. On the other hand, the existence of electric fields perpendicular to the magnetic field can cause ion drift across the magnetic field when the phase velocity of these waves is approximately equal to the ion velocity. As is evident from the table, this situation can arise in certain modes of operation. For a more detailed explanation of the effect of the cyclotron instability on ion loss and electron loss, it will be necessary to carry out further investigations. The author wishes to take this opportunity to thank I. N. Golovin for his continued interest in this work and for a number of valuable comments offered in discussions of the experimental results. E. P. Velikhov for help in carrying out the calculations, and A. N. Karkhov and V. F. Nefedov for help in carrying out the measurements with Ogra. Fruitful discussions of the experiments and the results of the calculations with colleagues working with Ogra were very helpful in determining the physical pattern of these effects.Translated from Atomnaya Énergiya, Vol. 14, No. 1, pp. 72–81, January, 1963     

The determination of the displacement energy in type 316 austenitic steel

The displacement energy E_d in the 110 direction, which is a good approximation to the polycrystalline value in face-centred cubic metals, has been measured in type 316 austenitic steel at high temperatures using a high-voltage electron microscope to both produce and observe loop growth, dislocation flux and void swelling as a function of electron energy. In the loop growth experiments the threshold voltage for displacements was directly measured, in the other methods the normalized results were compared with Oen's calculated cross sections assuming various values of E_d. The latter method assumes that the effect per electron is independent of dose rate, and this has been verified for void-swelling. The results obtained from all the experiments lie in the range E_d = 18 ± 1.5 eV.     

n沟VDMOSFET单粒子烧毁的二维数值模拟

应用半导体器件二维模拟软件Medici对功率MOSFET器件单粒子烧毁SEB(Single Event Burnout)效应开展了理论模拟研究。理论模拟与以往的实验结果比较吻合,证明采取的物理模型的正确性。得到了SEB灵敏度与载流子浓度、基区宽度和发射结掺杂浓度等参数的变化关系,提出了改善SEB的几种加固措施。该模型对于评估器件SEB效应提供了理论方法。