新型横向脉冲快放电S2激光管的设计

针对放电型S2激光管的设计中始终未能很好解决电极可拆卸性及可靠性的难题,首次提出了一个以不锈钢材料作激光管管壳,借助于燕尾槽实现电极可拆卸的设计方案,从而为横向脉冲快放电型S2激光器实现激光振荡创造了条件.     

大容量电容容量简易测量电路

本文介绍一种大容量电容容量简易测量电路,原理如附图所示.其中,Cx是被测电容,常开型按钮开关S3用于对被测电容Cx进行放电.每次测量前应先按动S3将Cx彻底放电.S2是Cx充电定时电阻选择开关.S1是电源开关,当其接通后,+6V电压开始对Cx充电,同时B点得到经VD1、VD2正向压降钳位的稳定电压,指针式石英钟开始计时.     

S2激光器泵浦源的设计

S2激光器产生的蓝—绿激光波长范围为430—520nm,根据理论计算,采用放电泵浦S2双原子分子的泵浦电流脉宽应小于30ns．以Blumlein电路作为泵浦源,设计合理的电路结构,传输线采用宽带引线,减小回路的寄生电感,实现了稳定的快脉冲放电,满足了对放电电流的要求,为放电激励是激光器产生激光提共了条件。     

S2/激光器横向脉冲放电特性的研究

研究了S2激光器横向脉冲放电特性.分析并解释了影响电特性的主要因素,如等离子体温度,充电电压,电容配比及紫外光预电离.     

新型横向脉冲快放电S_2激光管的设计

针对放电型 S2 激光管的设计中始终未能很好解决电极可拆卸性及可靠性的难题 ,首次提出了一个以不锈钢材料作激光管管壳 ,借助于燕尾槽实现电极可拆卸的设计方案 ,从而为横向脉冲快放电型 S2 激光器实现激光振荡创造了条件。     

形成KrⅡ469.5nm激光振荡的动力学过程

用自吸法测试了不同放电条件下在He-Kr空心阴极放电的余辉阶段中Hem(2s3S1)态布居密度随时间的变化.进而计算了这一亚稳态原子和氪基态原子彭宁电离速率常数,从而更深入地讨论了这一激光振荡的激励机制.     

Ne瞬态OGS的机理研究

考察了空阴极放电管中各种放电电流时氛1S→2P的光电流讯号(OGS),在放电电流足够小时1S_2-2P态和1S_i(i=3,4,5)→2P态跃迁的光电流讯号之间的镜像对称性被破坏.本交给出了基于三态模型和阴极轰击弛豫过程假说的理论分析,与实验结果一致.     

电源技术

Y2002-63332-1644 0304998电池充电状态估价=Battery state-of-charge estimation[会,英]/Pang,S.& Farrell,J.//Proceedings of the2001 American Control Conference Vol.2 of 6.—1644～1649(HE)0304999蓄电池组放电时间的计算[刊]/谢拥华//电信技术.—2002,(10).—71～73(L)主要讨论了蓄电池组放电时间的计算方法,并详细阐述了影响蓄电池组放电时间计算准确性的因素,最后给出了一种较为准确地计算蓄电池组放电时间的方法。     

氮分子中3577埃强激光的实验研究

J.Itani等首先在Blumlein快放电装置中用SF_6和N_2的混合物作为工作介质获得了强的3577埃激光作用.以后S.N.Suchard和R.P.Akins对(SF_6+N_2)混合物快放电激发的3577埃氮分子激光进行过研究.我们在本文中报导的是在改进的Blumlein型横向双放电装置中用适量纯氮进行放电激发时,所产生的氮分子激光中有波长3577埃激光,另外在适当SF_6和N_2的比例及总气压下观察到氮分子3159埃高增益受激发射.我们实验中所用的,是由带有直角三角形平板传输线作为脉冲形成网络的Blumlein 快放电装置,在装置的放电区域接近阴极的部分插入了第三电极A_3,这个第三电极我们称之为诱导电极,它在快放电中起着改变阴极发射性质并起使激活空间预电离的作用.整个装置图1所示.     

V2O5(TiO2)/S复合材料作锂电池正极的性能研究

为了改善锂硫电池的循环性能,将单质硫分别与纳米金属氧化物(V2O5,TiO2)机械混合。用XRD对材料的晶体结构进行了表征。通过循环伏安、交流阻抗和电池性能的对比,对材料的电化学性能进行了分析。结果表明:采用V2O5改性的硫材料,首次放电比容量达844.68 mAh.g–1,样品循环容量衰减明显改善,30次后比容量保持在696.71 mAh.g–1。而TiO2/S复合材料,初始放电比容量为578.21 mAh.g–1,30次循环后比容量为347.71 mAh.g–1。     

磁约束放电CO激光模型的研究

建立了磁约束放电 CO激光的模型。在该模型下分析、计算了 CO气体放电系统电子的能量分布函数 ;CO分子的电子碰撞激发速率 ,CO分子各振动态的布居数分布和对应的小信号激光增益系数。研究表明 ,由于磁场的加入 ,在对应 CO分子振动态电子碰撞激发截面的能量范围内电子数有较大的增加。CO分子的电子碰撞激发速率提高。CO分子各振动能级均获得更大的布居数和激光小信号增益。     

100 J侧面滑闪预电离TE CO2激光器

提出了一种新型侧面滑闪放电技术,为TE CO2激光器均匀放电提供高效、均匀的紫外预电离。采用这种技术,成功实现5.5 cm电极间距的高气压CO2均匀放电,放电截面达27.5 cm2。放电体积为5.5 cm×5 cm×90 cm的单元模块采用V(CO2)∶V(N2)∶V(He)=1∶1∶4的混合气体在60 kPa的气压下,获得了53 J的激光脉冲输出,激光比输出能量达3.46×10-4J/(L.Pa)。采用简单的谐振腔,利用两个相同的单元模块串联实现了103 J的激光输出。实验表明双模块器件存在很强的激光脉冲能量增强效应,双模块串联输出的激光能量比单模块激光能量的两倍还大15%。     

Kinetic modeling of CW CO electric-discharge lasers

A rate equation analysis of convective CO electric-discharge lasers (EDL's) is presented. The spatial distribution of CO vibrational levels is governed by a kinetic master equation which contains terms representing electron impact pumping, vibration-vibration (VV) and vibration-translation (VT) energy transfer, and spontaneous and stimulated emission. Electronic pumping rates are derived from the solution to the electron Boltzmann equation. Spectral distributions of small-signal gain and optical flux are calculated in terms of the cross sections for these processes. Good agreement is obtained between predicted and experimentally reported gain and power spectra. For coincident discharge/cavity configurations, the quasi-steady small-signal gain is predicted to have a strong dependence on translational temperature for representative operating conditions. The predicted power output for a wide variety of bulk gas and plasma properties is found to be correlated by a simple energy-time parameter. The performance of other devices which involve separate discharge and cavity regions is also examined. The importance of the threshold excitation energy in understanding a variety of configurations is discussed.     

Saturation studies of the E-beam sustained discharge atomic xenonlaser

In an electron beam sustained discharge xenon laser the discharge energy deposition has been varied in order to investigate the saturation effect on the xenon laser. The current density of the electron beam is varied separately in the range of 0.1-2.7 A/cm² to obtain optimized discharge excitation conditions as a function of electron beam current density and gas pressure. An optimal fractional ionization f=3.5-4×10^-5 is found, independent of the electron beam parameters. The synergy of electron beam and discharge excitation has resulted in a maximum specific energy of 15 J/l at a total gas pressure of 9 bar     

脉冲HF激光器预电离设计及效果评估

气体介质稳定体放电是放电激励气体激光器高效输出的基础和前提,预电离是实现高压气体介质稳定体放电的有效技术途径之一。基于放电激励脉冲HF激光器电气结构总体设计要求设计了结构紧凑的紫外光自动预电离装置, 并对其在气体介质中预电离产生的初始电子数密度进行了数值模拟。模拟结果表明:在整个放电区域内初始电子数密度均在109/cm3左右,满足介质体放电要求。通过激光器能量输出实验评估了预电离效果,对SF6和H2混合气体介质,在充电电压较低时,输出能量有数倍的提高;对SF6和C2H6混合气体介质,在充电电压20 kV时激光器输出能量由200 mJ提高至297 mJ,提高了近50%。实验结果表明:该预电离装置对改善激光器能量输出特性有明显效果。     

磁约束放电的CO激光激发系数

采用磁约束放电CO激光模型研究在外磁场作用下:(1)放电系统电子的能量分布变化;(2)电子对振动态CO分子的碰撞激发几率;(3)CO分子振动平动,振动转动激发系数与磁场、温度的关系.研究表明,外磁场使原电场在电场方向上对电子作用变小,电子能量减小,并导致电子对CO分子的碰撞激发几率系数下降,而对V-V,V-T激发系数影响不大.     

Characteristics of pulse excited electroluminescence from ZnS films containing rare earth fluroide

The transient behavior of the electrical and the optical properties under pulse excitation has been studied and analyzed in detail on the electroluminescent devices made of Au-ZnS: NdF3- Ta2O5-Ta composite films. The ZnS-Ta2O5interface is capable of accommodating a large number of trapped electrons, up to 10¹³cm^-2, with the majority of the interfacial states located at a fixed energy below the conduction band of ZnS. Carrier injection is achieved by electrons tunneling through the Au-ZnS Schottky barrier at a field of 2.6×10⁶V/cm. The threshold field of impact excitation for 1 percent NdF3in ZnS was found to be 1.5×10⁶V/cm; while the coefficient of impact excitation at 2.6×10⁶V/cm was estimated to be 1750 cm^-1. In addition, the emission time constants of several rare earth fluorides were also studied.     

S-on-1测量方式下薄膜激光损伤的累积效应

为了研究薄膜激光损伤机理及影响因素,基于平顶光束辐照测量的原理,采用1064nm的Nd:YAG激光器,对电子束热蒸发方式镀制的HfO₂薄膜在重复频率激光作用下损伤的累积效应进行了理论分析和实验验证。运用损伤阈值的测量原理,分析了1-on-1和S-on-1两种测量方式的特点,并分别开展了测量实验。采用二分法查找辐照激光能量,每个能量密度辐照20个测试点,应用零几率损伤阈值和最小二乘法拟合确定测量结果。结果表明,对同种薄膜,1-on-1测量方式测得的损伤阈值为15.75J/cm2,S-on-1测量方式测得的损伤阈值为11.90J/cm2;从损伤阈值与损伤形貌两方面的对比表明,S-on-1测量方式体现了典型的累积效应。此结果对深入研究薄膜激光损伤的机理和影响因素具有重要意义。     

Excitation cross section of some of the states of NE II, Ar II, and KR II by electron collision

The sudden perturbation method has been used to calculate the excitation cross section of some of the states of Ne II, Ar II, and Kr II by high energy electrons. In this method, the ground state of the noble gas atom, after a collision with a fast electron, is considered to lose one of its valence electrons in a time shorter than the relaxation time of the atom. The resulting configuration is then assumed to be a|(p^{5}) ^{2}P_{j}ranglestate withJ = 3/2or 1/2, with the remaining five valence electrons having the same radial coordinates as in the original|(p^{6})^{1}S_{0}ranglestate of the neutral atom. The configuration|(p^{5})^{2}P_{j}rangleis then expanded in terms of the ionic wave functions having the form of|(p^{4})bar{L}bar{S}, nl', LSJrangle, wherebar{L},bar{S}designate the total orbital angular momentum and the total spin angular momentum of the core electrons,l'is the orbital angular momentum of the excited running electron, andLSJdesignates the final orbital, spin, and total angular momenta of the atom. The coefficients of the expansion are calculated in terms of the coefficients of fractional parentage and3-jsymbols. The radial wave functions for the neutral atoms and their excited ionic states for the involved radial integrals are obtained by using a computer program giving the self-consistent Hartree-Fock wave functions in the Slater approximation. Since no experimental measurements for the excitation cross sections with fast electrons are given, the results of the calculations are indirectly compared with the available work reported on the pulsed Ar II laser. Population of various excited ionic states is calculated assuming a uniform energy distribution of electrons having 1.8 times the ionization threshold of argon, and the results are compared with experimental data reported in the literature.     

Rb(52DJ,7S)+Rb(5S)间的碰撞能量转移

利用脉冲激光双光子激发Rb(5S)到Rb(5DJ,7S)态,在样品池条件下,利用原子荧光光谱方法研究了Rb(SDJ,7S)+Rb(5S)的碰撞能量转移过程.利用三能级模型的速率方程分析,在不同的Rb(5S)密度下,通过对直接荧光和转移荧光的时间积分荧光强度的测量,得到了Rb(5D5/2)→Rb(5D3/2)精细结构转移截面为(3.7±0.9)×10-14cm2.而测得的碰撞转移到Rb(5DJ)以外态的截面是Rb(5D)→Rb(7S)转移截面和碰撞能量合并逆过程截面之和,还可测得Rb(5D)→Rb(7S)的碰撞转移截面为(1.6±0.4)×10-16cm2,故Rb(5D)+Rb(5S)→Rb(5P)+Rb(5P)的截面分别为(3.1±1.2)×10-14cm2(对J=5/2)和(2.0±0.6)×10-14cm2(对J=3/2),5DJ态主要是通过碰撞能量合并的逆过程(即Rb(5DJ)+Rb(5S)→Rb(5P)+Rb(5P))猝灭.