高密度氩等离子体电子密度的计算

用屏蔽氢离子模型计算了冲击压缩产生的温度T～2.0eV、密度ρ～0.01g/cm3～0.49g/cm3范围内氩等离子体的电子密度,探讨了不同温度、密度范围内的高密度氩等离子体中粒子之间相互作用对电子密度的影响.     

氧氩比对钴掺杂氧化锌薄膜光电性能的影响

以氧化锌陶瓷靶和金属钴靶为靶材,利用磁控共溅射方法制备钴掺杂氧化锌(Co-ZnO)薄膜。研究了氧氩比对薄膜的结构、光学和电学性能的影响。结果表明:薄膜具有类似于ZnO的六方纤锌矿结构,并沿c轴择优生长;当氧氩比为2:8时,薄膜具有较好的纳米晶粒和表面结构,其霍尔迁移率为2.188×104cm2/V·s,最小电阻率为1.326×104Ω·cm,其薄膜透光率最高,且在紫外区有一个相对较强的发射峰。     

氩氦刀系统低温探针制冷性能实验研究

氩氦刀系统低温探针的温度及制冷量,主要取决于氩气进气温度和节流压力。文中介绍了氩氦刀低温探针的结构、工作过程以及对5mm直径低温探针的制冷性能试验。试验结果表明,当进气压力为20MPa时,1分钟内探针端部在296.3K的空气中,最低温度可达112.9K;当进气压力为18MPa时,探针在291K的水中5分钟内能够形成4.9cm×2.8cm的椭圆冰球;将预冷进气温度从290.4K降低至274.4K,可以使探针制冷量增加约24%。     

飞秒强激光经氩气和氩团簇的传播

通过数值求解三维电场传播方程,理论模拟了飞秒强激光脉冲（50 fs,1016 w/cm2）在氩气和中等尺寸氩团簇中的传播效应.结果表明,飞秒强激光脉冲经氩气传播将发生频谱蓝移展宽和光束发散;而经中等尺寸氩团簇传播,则存在一定程度的自聚焦效应.     

氧氩比对SnO2/Ag/SnO2透明导电膜光电性能的影响

在室温及不同的氧氩比条件下,采用射频磁控溅射Ag层和直流磁控溅射SnO2层,在载玻片衬底上制备出了SnO2/Ag/SnO2多层薄膜.用霍尔效应测试仪、四探针电阻测试仪和紫外-可见-近红外光谱仪等表征了薄膜的电学性质和光学性质.实验结果表明:当氧氩比为1:14时,所制得的薄膜的光电性质优良指数最大,为1.69×10-2 Ω-1;此时,薄膜的电阻率为9.8×10-5Ω·cm,方电阻为9.68Ω/sq,在400～800 nm可见光区的平均光学透射率达85％;并且,在氧氩比为1:14时,利用射频磁控溅射Ag层和直流磁控溅射SnO2层在PET柔性衬底上制备出了光电性质优良的柔性透明导电膜,其在可见光区的平均光学透过率达85％以上,电阻率为1.22×10-4Ωcm,方电阻为12.05Ω/sq.     

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用Langmuir探针对射频(13.56 MHz)感应等离子体进行了诊断,给出了Ar等离子体轴向和径向参数随气压的变化。采用发射光谱测量了等离子体中氩原子的750.3nm谱线强度随气压在轴向的变化,其变化趋势与Langmuir探针测量结果的变化趋势相一致。测量了氩离子的434.8nm谱线强度随气压在轴向的变化并获得了氩离子的434.8nm谱线强度与氩原子的430.0nm谱线强度的比值在轴向三个不同位置的变化。从测得的结果可知:在放电室中上部形成了均匀稳定的高密度等离子体,在靶附近有所降低,在中部以下等离子体密度逐渐变低;在径向6~7 cm以内的区域等离子体参数变化不大,形成了均匀稳定的等离子体,等离子体参数在器壁处变化明显。     

非线性一维光子晶体光开关与光双稳

设计和制备了ZnS/ZnSe叠层共 2 0个周期的非线性一维光子晶体光开关与光双稳器件 理论模拟了波长 5 14 .5nm的氩离子激光 ,在阈值功率密度 1.0× 10 5W/cm2 下 ,完全移出光子禁带 ,实现了光开关 同一器件也可作为光学双稳器件 ,实验测出其阈值功率密度为 1.38× 10 5W/cm2 ,双稳开关时间为 10 0ps 理论与实验结果基本一致     

基于双程放大的毛细管放电69.8 nm激光增益特性

建立了类氖氩C线69.8 nm激光的双程放大实验后反射腔结构,利用45 cm长毛细管作为放电负载得到了其双程放大输出.在相同初始实验条件下,分别测量了单程放大输出与双程放大输出的激光脉冲光强、脉冲宽度以及激光束散角.通过对比单程与双程输出实验结果,利用双程放大激光光强的计算公式,分析得到了增益持续时间大于4 ns,以及增益在毛细管径向上的分布特点.以上结果为建立谐振腔进行毛细管放电类氖氩激光的多程放大实验奠定了基础.     

氩原子基态波函数和能量的解析计算

以第一性原理和变分原理为基础,给出了氩原子基态波函数的一种解析表达式,计算了基态氩原子(含类氩离子)的能量,导出了所涉及的所有积分的解析表达式.对氩原子,所得到的能量理论值与实验值的相对误差为0.22%.     

大容量高密度体全息数据存储

基于晶体体全息存储机理 ,采用半导体泵浦固体激光器取代氩离子激光器作为系统光源 ,设计并构建了小型体全息存储器 ,实现了 15 0 0幅等衍射效率高分辨率全息图的记录和复现 ,其存储容量大于 1 1Gbit ,存储密度大于1 4Gbit/cm3 。     

High Performance, Low Energy Ion Source

An ion accelerator system using one or two fine mesh tungsten grids has been used in a magnetic multipole containment ion source to produce a continuous positive ion beam variable over a wide range of beam currents and accelerator voltages. The ion source plasma is low noise and uniform to ± 1% density variation over 9 cm diameter. Beams up to 4 cm × 4 cm have been extracted which have low divergence (±1%), uniform current density (±2%), small ion energy speed, beam ion energy variable from 200V to several thousand volts, and current densities variable from ?A per cm2 to tens of milliamperes per cm2, limited only by acceleration grid power loading or sputtering.     

Electron beam extraction from a broad-beam vacuum-arc metal plasmasource

We describe experiments demonstrating the formation of a high current electron beam from a vacuum arc plasma. A preexisting vacuum arc ion source was used, with the extraction voltage reversed in polarity so as to form an electron beam rather than an ion beam; no other changes were required. The beam formed was of energy up to 33 keV, beam current up to 70 A, beam diameter about 10 cm, pulse width 500 μs, and energy density up to 25 J/cm². This kind of source can be used for material surface modification     

锂离子束通过钠蒸汽时的中性化效率测量

本文叙述了锂离子束通过钠蒸汽时的中性化效率测量。锂离子源选用锂辉石作发射材料,中性化电荷交换系统由内径为25mm,长度约为120mm的中性化管道和钠蒸发器组成。使用复合型法拉弟筒作为探测器,测量的能量范围1—8keV,最佳中性化效率在96％—94％之间。     

Laser ion beam formation for nanotechnologies

It is suggested to generate cold ion beams by laser collimation and subsequent laser ionization of a primary atomic beam. The primary beam, formed by a standard method, is collimated through transverse cooling by resonance laser radiation. Laser radiation is also used for the multistep ionization of atoms in the collimated beam. Advantages of the proposed method are a low scatter of the initial ion energy (below 10^?1 eV) and a high emittance in the region of the virtual source (～10^?6 cm rad at a beam current on the level of microamperes). The high monochromaticity of the obtained ion beam allows the chromatic aberration effect to be significantly suppressed, which implies good prospects for using such sources in ion beam lithography. The proposed method also allows the spectrum of elements used in ion beam sources to be expanded, which is an independent technological advantage.     

Ion beam enhanced deposition of AINxOy alloys on InP

AIN_xO_y alloy films are deposited on InP by low energy (20 eV) ion beam enhanced reactive evaporation of aluminum in ultra-high vacuum. The resistivity of the films ranges between 10¹⁵ and 10¹⁶ Ω cm and the dielectric strength exceeds 10⁶ V/cm. The energy of the ions is kept below the threshold energy (found to be in the range 20–100 eV) beyond which ion bombardment of InP surface results in irreversibly degraded electronic properties. Despite this precaution, further improvement of interface properties (implying lowering of ion energy and appropriate post-annealing schemes of the structures) are required for a full development of this technique, which is compatible with the molecular beam epitaxy technology.     

Nitrogen ion spectrum from a low energy plasma focus device

The nitrogen ion spectrum generated from a low energy Mather-type Plasma Focus device is reported. The main species of ions present are N ⁺¹, N⁺², and N⁺³. It is found that its relative concentrations at a distance of several cm from the ion source are in agreement with those predicted for an equilibrium charge-state of the beam, and hence the spectrum of the neutral nitrogen is also derived. By taking into account the lateral spread of the beam due to multiple elastic scattering with the background gas, the derivation of absolute values for the total ion spectrum within the investigated energy range (>170 keV), the total number and total energy of the fast particles has been obtained     

Surface Discharges for Soft X-Ray Preionization in Light-Ion-Fusion Accelerators

We are investigating surface discharges as extreme ultraviolet (XUV) photon sources for preionizing anode surfaces of ion diodes in light-ion-fusion accelerators. Preionization is important both to control the diode impedance and to efficiently generate an ion beam. The surface discharges and their power feeds were constructed in a strip-line configuration to minimize overall system inductance. In some cases a 0.6-?F peaking capacitor was added to the circuit as close as possible to the surface discharge. These discharges radiated peak XUV powers of over 20 MW and total energies of over 5 J when driven by a low-energy (480 J) capacitor bank. These discharges were used to preionize the anode surface in an Applied-B diode on the Nereus accelerator (500 kV,40 kA). Preionizing a cleaned LiF anode with 60 kW/cm2 of XUV photons resulted in improved beam uniformity, flatter impedance profile, and a factor of 4 more ion beam energy coupled through the diode.     

金属杂质辅助低能氩离子束诱导蓝宝石自组织纳米结构

使用实验室自主研发的等离子抛光与刻蚀系统,研究了不同入射能量下不锈钢杂质辅助Ar+离子束刻蚀蓝宝石表面自组织纳米结构的形成机制.采用Taylor Surf CCI2000非接触式表面测量仪和原子力显微镜分别对刻蚀后蓝宝石样品的粗糙度、纳米结构的纵向高度和表面形貌进行了分析.研究表明:引入不锈钢杂质后,当离子束入射角度为...     

Use of the direct negative Cu ion beam deposition for the control of the properties of Cu thin film

Direct metal ion beam deposition (DMIBD) technique for Cu thin film metallization is characterized. With suitable operating conditions, secondary Cu⁻ ion yield, ion/atom arrival rate ratio, ion beam energy spreads were optimized at 15%, 0.3, and 10%, respectively.After optimization of DMIBD system, the effect of Cu ion beam energy on the resistivity, adhesion strength, and surface morphology of Cu thin film was investigated. TEM micrograph shows that the film prepared at 75 eV was polycrystalline, while the film prepared at 0 eV was vertical columnar structure.As ion beam energy is increased from 25 to 75 eV, the resistivity is decreased from 6.21 to 2.09 μΩ cm, while the critical load to cause adhesion failure was increased to about 13 N at 200 eV, which is four-times higher that that of 25 eV.     

强流脉冲离子束能量密度分布的红外诊断

强流脉冲离子束在靶上的能量密度分布是其研究和应用的一个重要参数。为了解决现有束流能量密度诊断方法的不足,利用红外成像仪测量靶背面的温度分布,从而建立了强流脉冲离子束能量密度分布的红外诊断方法。对能量密度1J/cm2量级、脉冲宽度为102 ns量级的束流,该方法测量误差好于5%,空间分辨率可达到1~2mm,具有操作简便、成本低的优点,是强脉冲能量沉积分布的一种高效迅速的诊断方法。