共查询到20条相似文献,搜索用时 750 毫秒
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报道了毛细管放电69.8 nm软X射线激光的光强分布特性. 实验中所用毛细管长度为35 cm, 放电主脉冲电流幅值为11.5 kA, 放电初始气压为14-16 Pa. 测得的光斑强度分布由两部分构成, 在中心有一个占光强绝大部分的主峰, 其发散角约为0.4 mrad, 边缘还有两个小的离轴峰, 峰-峰发散角约为1.5 mrad. 理论上采用几何光学近似的方法对其光强分布进行计算, 光斑如此小的发散角主峰的出现, 可能主要是由于毛细管放电过程中电子密度在轴心处具有轻微凹陷造成的. 相似文献
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利用x射线二极管(XRD),实验上测量了毛细管放电激励下类氖氩469nm软x射线激光的尖 峰信号. 改变毛细管的充气气压和主脉冲放电电流,研究了激光尖峰的产生时间随实验参数 的变化情况. 实验结果表明,激光产生于主脉冲电流波形的前沿,此时的主脉冲电流是其峰 值的65%—75%. 增加毛细管充气气压或者减小主脉冲峰值电流,激光的产生时间将会稍有延 迟. 同时改变毛细管充气气压时,激光尖峰信号在42Pa存在最大值.
关键词:
毛细管放电
软x射线激光
激光产生时间 相似文献
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类锂钙和钾离子X射线激光的实验研究 总被引:1,自引:0,他引:1
探索进入“水窗”波段以寻求X射线激光在近期的科学技术应用,是当前实验室X射光线激研究的一个重要目标.采用复合泵浦方案,我们曾用较低的驱动激光功率首次实现了类锂硅离子5f—3d(8.884nm),5d—3p(8.728nm)跃迁软X射线激光,并第一次发现了类锂硅离子的6f—3d(7.583nm)和6d—3p(7.464nm)新的X射线激光跃迁.最近,我们进一步完成了线聚焦激光辐照CaF_2和KCl平板靶的实验,探索了沿类锂离子等电子数序,将软X射线激光推进至更短波长的现实可能性,实现了类锂钙和类锂钾4f—3d跃迁的软X射线激光,波长分别为5.77nm和6.47nm,增益系数分别达到4.3cm~(-1)和1.6cm~(-1).同时也观察到了类氢氟Hα(8.09 nm)的增益,增益系数为1.4cm~(-1).实验结果进一步显示了复合泵浦类锂离子方案在实现更短波长X射线激光方面的潜力. 相似文献
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毛细管放电条件下类氖序列原子参量计算与分析 总被引:2,自引:0,他引:2
利用多组态求解相对论性的Hartree-Fock-Roothan方程(HFR)方法计算了类氖离子(Z=13~27)2s^22p^5—2s^22p^53s能级之间跃迁的原子参量,包括类氖氩激光系统的能级,振子强度,自发辐射衰变速率,能级寿命,电子碰撞激发截面及电子碰撞激发速率系数等。以类氖氩离子为例,分析了等离子体内46.9nm激光跃迁的粒子数反转的形成及谱线放大过程,讨论了其它几条谱线产生增益的可能性,分析了激光线振子强度随核电荷数的变化规律。根据获得的原子参量,计算了利用毛细管放电产生类氖氩和类氖氪x射线激光的放电参量,其中类氖氩毛细管放电的初始压强的范围为30~90Pa,放电电流峰值为10~50kA。理论计算结果为类氖氩x光激光实验分析,深入研究等离子体反转动力学,激光增益的估算及理论方案设计等提供了基本数据。 相似文献
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理论和实验上研究了Xe介质毛细管放电极紫外光源等离子体时间特性和最佳条件. 从理论上建立了Xe介质一维辐射磁流体力学模型,模拟了不同气压和电流条件下等离子体压缩和辐射特性;实验上测量了放电电流30 kA时不同气压条件下13.5 nm (2%带宽)动态特性. 理论和实验结果表明:不同放电电流条件下,存在最佳气压值,最佳气压随着电流的增加而增加;同时,电流增加时,13.5 nm (2%带宽)辐射光强峰值时刻减小.
关键词:
极紫外光刻光源
毛细管放电
磁流体力学
Xe等离子体 相似文献
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基于速率方程理论,建立了光抽运气体波导产生太赫兹(THz)激光的能量转化模型,理论分析并求解得到抽运光吸收系数、THz小信号增益系数以及THz输出功率表达式.计算结果表明,THz输出功率随工作物质气压的升高先增加后逐渐减少,随抽运功率的增加、输出镜反射率的减小而增加;最佳工作气压随抽运功率的增大而增大;激发态粒子数以及THz光子通量随波导截面径向逐渐减小,而THz小信号增益系数逐渐增加;抽运饱和、弱抽运吸收与激发态工作物质对THz激光的吸收是限制激光转化效率提高的根源;基于该模型的计算结果与相关文献中的实验数据符合较好. 相似文献
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实验中测量了0.38V_(Bohr)(460 keV)高电荷态Xe~(q+)(4≤q≤20)离子轰击高纯Ni表面发射的400-510 nm光谱.实验结果包括NiⅠ原子谱线,NiⅡ离子谱线,以及入射离子中性化发射的XeⅠ,XeⅡ和XeⅢ谱线.研究了谱线XeⅡ410.419,XeⅢ430.444,XeⅡ434.200,XeⅡ486.254,NiⅠ498.245,NiⅠ501.697,NiⅠ503.502,NiⅠ505.061和NiⅠ508.293 nm的光子产额随着入射离子电荷态的变化.结果表明,入射离子中性化和溅射Ni原子发射谱线的光子产额随着入射离子电荷态的增加而增加,其趋势与入射离子势能一致. 相似文献
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Lilly J.L. Subramanian V.V. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》2001,29(6):927-934
Formation of an atmospheric pressure dusty air plasma is explored experimentally in this paper. The plasma is created by seeding an air flow with graphite particles and irradiating the particulates with a focused CO2 laser beam. The graphite particles are, thus, heated to thermionically emitting temperatures, and average particle temperatures and average particle number densities are measured. The presence of charges is inferred both from these measured quantities using a simple theoretical transient model, and experimentally by applying a dc bias across the irradiated region. It is found that an electron density of ~6.7 × 105 cm-3 (6.7 × 1011 m-3) can be produced at steady state in the presence of O2. This value can be increased to 3.6 × 107 cm-3 (3.6 × 1013 m -1) in the ideal case where an electron attachment to O2 is suppressed and where a lower work function particulate is used 相似文献
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Bauer H.R. Kirkman G. Gundersen M.A. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1990,18(2):237-246
Temperature, energy, and densities of two electron distribution function components, including an isotropic bulk part and an anisotropic beam, are analyzed for a hydrogen pseudospark and/or back-lighted thyratron switch plasma with a peak electron density of 1-3×1015 cm-3 and peak current density of ≈104 A/cm2. Estimates of a very small cathode-fall width during the conduction phase and high electric field strengths lead to the injection of an electron beam with energies ⩾100 eV and density of 1013-1014 cm-3 into a Maxwellian bulk plasma. Collisional and radiative processes of monoenergetic beam electrons, bulk plasma electrons and ions, and atomic hydrogen are modeled by a set of rate equations, and line intensity ratios are compared with measurements. Under these high-current conditions, for an initial density n H2=1016 cm-3 and electron temperature of 0.8-1 eV, the estimated beam density is ≈1013 -1014 cm-3. These results suggest the possibility of producing in a simple way a very high-density electron beam 相似文献
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Pedrow P.D. Nasiruddin A. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1989,17(1):17-23
Langmuir probe, photodiode, and optical multichannel analyzer (OMA) measurements have been made on a pulsed CF4 conical theta-pinch plasma. A cloud of CF4 was puffed into a conical theta-pinch coil, converted to plasma, and propelled into the vacuum region ahead of the expanding gas cloud. At a position 67 cm away from the conical theta-pinch coil, the plasma arrived in separate packets that were about 20 μs in duration. The average drift velocity of these packets corresponded to an energy of about 3 eV. The OMA measurements showed that the second packet contained neutral atomic fluorine as well as charged particles. The electron temperature and ion density in the second packet were 2.0 eV and 1.5×1013 cm-3, respectively. The electron temperature and ion density in the wake plasma were 8.3 eV and 4×1011 cm-3 , respectively. This device can be used for plasma processing or as a laboratory test of numerical and analytical models of the expansion of plasma into vacuum 相似文献
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K-band electron spin resonance (ESR) at 4.3 K has revealed the dipole-dipole (DD) interaction effects between [1 1 1]Pb centers (*Si ≡ Si3 defects with unpaired sp3 hybrid [1 1 1]) at the 2 dimensional (1 1 1)Si/SiO2 interface. This has been enabled by the perfectly reversible H2 passivation of Pb, which affects the defect's spin state. Sequential hydrogenation at 253–353°C and degassing treatments in high vacuum at 743–835°C allowed to vary the Pb density in the range 5 × 1010 < [Pb] (1.14 ± 0.06) × 1013 cm-2. With increasing [Pb] fine structure doublets are clearly resolved. It is found that (1 1 1)Si/SiO2 interfaces, dry thermally grown at ≈920°C, naturally comprise a *Si ≡ Si3 defect density — passivated or not — of 1.14 × 1013 cm-2. 相似文献
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GeSn (0.524 eV) single-junction thermophotovoltaic cells based on the device transport model 下载免费PDF全文
Xin-Miao Zhu 《中国物理 B》2022,31(5):58801-058801
Based on the transport equation of the semiconductor device model for 0.524 eV GeSn alloy and the experimental parameters of the material, the thermal-electricity conversion performance governed by a GeSn diode has been systematically studied in its normal and inverted structures. For the normal p+/n (n+/p) structure, it is demonstrated here that an optimal base doping Nd(a) = 3 (7)×1018 cm-3 is observed, and the superior p+/n structure can achieve a higher performance. To reduce material consumption, an economical active layer can comprise a 100 nm-300 nm emitter and a 3 μm-6 μm base to attain comparable performance to that for the optimal configuration. Our results offer many useful guidelines for the fabrication of economical GeSn thermophotovoltaic devices. 相似文献
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报道了Gd3+离子在GdB3O6基质中的光子级联发射特性。用Hitachi M850荧光分光光度计测定了Gd3+ 6GJ能态的位置和Gd3+离子的光子级联发射光谱,Gd3+离子的第一个光子发射为6GJ→6PJ(~600nm)和6GJ→6IJ(~780nm),第二个光子的发射为6PJ→8S7/2(~310nm)。由于6D9/2与6I11/2间能级差(~2900cm-1)和6I7/2与6PJ间能级差(~3900cm-1)较小,多声子弛豫的几率明显超过辐射跃迁几率。因此,当用8S7/2→6GJ(202nm)的紫外光激发时,只能观察到6PJ→8S7/2(~310nm)、6GJ→6PJ(~600nm)和6GJ→6IJ(~780nm)的发射跃迁,未能观察到6IJ→8S7/2(~275nm)和6DJ→8S7/2(~250nm)的发射跃迁。 相似文献
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研究了230MeV的208Pb27+辐照Al2O3样品及随后在600,900,1100K高温条件下退火后的光致发光特性。从辐照样品的测试结果可以清楚地看到在波长为390,450nm处出现了强的发光峰。辐照量为1×1013ions/cm2时,样品的发光峰最强。经过600K退火2h后测试结果显示,380nm发光峰剧烈增强,而其他发光峰显示不明显。在900K退火条件下,380nm的发光峰开始减弱,而在360,510nm出现了明显的发光峰,至到1100K退火完毕后380nm的发光峰完全消失,而360,510nm的发光峰相对增强。从被辐照样品的FTIR谱中看到,波数在460~510cm-1间的吸收是振动模式,经过离子辐照后,吸收带展宽,随着辐照量的增大,Al2O3振动吸收峰消失,说明Al2O3振动模式被完全破坏。1000~1300cm-1之间为Al—O—Al桥氧的伸缩振动模式,辐照后吸收带向高波数方向移动,说明其振动模式受到影响。辐照剂量较小的样品,损伤程度相对较低,经退火晶化后,振动模式基本恢复到单晶状态;辐照剂量较高的样品,损伤程度大,退火处理后表面变得较粗糙,振动模式并未出现,说明结构破坏严重。 相似文献