A study of the secondary electron yield γ of insulatorcathodes for plasma display panels

In order to provide a guideline in the search for the optimum cathode materials for plasma display panels (PDPs), formulas for the simple calculation of the secondary electron yield γ were derived from Hagstrum's theory for an insulator without impurity levels. From these, we obtained the generalized relations between γ and the band parameters of an insulator and the potential energy of an incident particle, which is an ion or a metastable atom. Unlike metals, it is not work function but the sum of band gap and electron affinity that essentially contributes to γ of an insulator, By applying these formulas, the γ values of BaO and MgO for He, Ne, Ar, Kr, and Xe ions and metastable atoms were practically calculated. In particular, the metastable atom-induced γ values of these insulators were calculated for the first time. The γ values of these insulators for these noble gas ions are determined by Auger neutralization only. As for MgO, which is at present the most useful insulator cathode for PDPs, the γ values for Kr and Xe ions become zero. These calculated γ values of MgO for all noble gas ions were compared with experimental results reported previously     

EXPERIMENTAL RESEARCH OF ELECTRO-OPTICAL CHARACTERISTICS OF NOBLE GASES IN AC PLASMA DISPLAY PANEL

Luminous spectra and electric characteristics of gas mixtures:Ar+He,Kr+He,He+Ne,He+Xe,Kr+Ar and Ar+Hg are investigated in order to find out a kind of gas mixture radiatingblue-green light.It was shown in the investigation that the gas mixture of Ar+Hg,which radiates blue-greenlight,and has higher brightness and lower firing voltage,is more satisfactory.     

交流等离子体显示板中惰性气体放电的电光特性实验研究

为了寻求一种供等离子体显示板用的发蓝绿光的混合气体,本文对Ar+He、Kr+He、He+Ne、He+Xe、Kr+Ar和Ar+Hg混合气体的发光光谱和电特性进行了研究。发现混合气体Ar+Hg较为满意,发光颜色为蓝绿色、亮度较高、着火电压较低。     

New infrared laser lines in argon, krypton, and xenon

Fourteen new infrared laser transitions in Ar, Kr, and Xe ranging from3.725 to 17.233 mum are reported. All of the Kr laser transitions and all but one of the Ar and Xe transitions have upper levels in thesordstate: the majority of the transitions satisfy the conditionDelta K = Delta J. Identification of a previously observed, unidentified laser line at 5.804 μm in Ar is given.     

Third-harmonic generation in argon, krypton, and xenon: Bandwidth limitations in the vicinity of Lyman-α

Using experimentally determined oscillator strengths and photoionization cross-sectional data, we compute the dispersion characteristics of Ar, Kr, and Xe up to their first ionization levels and determine the spectral regions in the VUV where these gases exhibit negative dispersion and so can be efficiently used for frequency tripling. We then investigate the bandwidths over which efficient tripling can be achieved in phase-matched gas mixtures. The bandwidth is limited by the rapidly varying dispersion in the vicinity of resonance transitions in the gases. In particular, we look at the case of frequency tripling 3647 Å radiation to 1215.7 Å (hydrogen Lyman-α) and show, that for fundamental wavelength bandwidths as narrow as 1 Å, the rapid change in refractive index with wavelength can preclude phase matching over the entire bandwidth of the radiation.     

Scaling characteristics of the XeF (C→A)excimer laser

The scaling characteristics and medium properties of an injection-controlled XeF(C→A) laser pumped by a 10-ns-high current density electron beam have been investigated. A five-component laser gas mixture, consisting of F₂, NF₃ , Xe, Kr, and Ar was optimized for the scaled laser conditions, resulting in 0.8-J output pulses at 486.8 nm, corresponding to an energy density of small-signal-gain measurements combined with kinetic modeling permitted the characteristics of the dependence of net gain on the electron-beam energy deposition and gas mixture composition, resulting in an improved understanding of XeF(C→A) laser operation     

F_2/Ne/Kr混合气体中三原子准分子Kr_2F形成速率常数的测定

本工作用Ne代替Ar作为缓冲气体,在快放电激励条件下,对Kr_2F的动力学过程进行了研究,观察到较强的Kr_2F荧光辐射,并用时间积分谱的方法测定了Kr_2F的三体形成速率常数。本文还指出了用Ne作为缓冲气体比用Ar作为缓冲气体更有利于增强Kr_2F的辐射。     

电子束泵浦XeF(C→A)激光的实验研究

给出了电子束泵浦XeF(C→A)准分子激光的实验资料并作了一些初步分析,这些结果是在选用最佳混合气体(对应电子束横向激发采用8大气压Ar,16托Xe,8托NF3;对应纵向激发采用2大气压Ar,8托Xe,3托NF_3)条件下得到的。着重研究了光学谐振腔对宽带内波长调谐性和输出功率的影响。用纵向电子束激发,在74毫微米宽带范围内(从455毫微米到529毫微米)得到了连续可调谐的窄带激光输出。当用棱镜作为色散元件时,其线宽约为5毫微米;如果用衍射光栅代替棱镜则线宽可窄至1毫微米左右。     

惰性气体超极化的光抽运方法及比较

某些无放射性的具有自旋特性的惰性气体同位素（如^3He和^129Xe）,可通过激光抽运超极化,得到很高的非热平衡极化度和长驰豫时间的惰性气体。极化后惰性气体同位素核磁共振的灵敏度提高10^3～10^5倍。介绍了目前极化惰性气体常用的两种方法——自旋交换光抽运和亚稳态能级交换。     

An investigation of the role of Ne, Ar, and Kr as buffer gas in a coaxial e-beam pumped KrF laser

The role of Ne, Ar, and Kr as a buffer gas was investigated in a KrF laser pumped by a coaxiale-beam. The coaxial diode has a length of 20 cm and the anode tube diameter is 1 cm. The tube can be pressurized with the laser gas mixture up to 12 bar while a current density of 250 A/cm²can be achieved. It is found that both the maximum energy extraction and the optimized gas pressure with each buffer gas increase in the sequence Kr-Ar-Ne. From the experimental results, the quenching parameters of Kr, Ar, and Ne are deduced.     

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.     

Electron-beam pumped KrF laser extraction measurements for high Kr concentration gas mixtures

Energy extraction measurements are obtained with a 350 ns electron-beam pumped KrF laser (Ar diluent) at Kr concentrations from 4-99.6 percent. During the measurements, the F2number density is held constant at8.9 times 10^{16}cm^-3, and the average pump rate is maintained at ≈120 kW/cm³by adjusting the total pressure of the gas mixtures in order to compensate for the different electron stopping powers of Ar and Kr. For the 4, 10, and 99.6 percent Kr cases, total pressures are 1040, 1004, and 665 torr, respectively. Average output efficiencies in percent of 9.3 at 4 percent Kr, 11.2 at 10 percent Kr, and 9.2 at 99.6 percent Kr are obtained. Peak power efficiencies in percent of 9.6 at 4 percent Kr, 12.5 at 10 percent Kr, and 11.6 at 99.6 percent Kr are derived from the data. Our computer model predictions agree with the results.     

Time-resolved spectroscopic study of high-pressure self-sustaineddischarge-pumped atomic xenon lasers

To explore the lasing kinetics of UV-preionized, self-sustained discharge-pumped atomic xenon (5d→6p) lasers, the time-resolved spectroscopy of the laser output from the multiline laser resonator is reported. The dilutents used were Ar and He. Increasing Xe concentration shortened the 1.73-μm laser pulse duration and decreased the total (multiline) laser output energy, because increased Xe metastable state population contributes to the increase of the 6p state population (lower laser level) by electron-impact excitation and radiation trapping during discharge pumping. High-excitation-rate pumping resulted in the decrease of the laser output power of 1.73- and 2.63-μm lines. Increasing the total gas pressure leads to high-efficiency operation due to modest-excitation-rate pumping at high pressures     

Kinetically tailored properties of electron-beam excited XeF(C → A) and XeF(B → X) laser media using an Ar-Kr buffer mixture

Use of a two-component buffer gas comprised of Ar and Kr results in electron-beam excited XeF(C rightarrow A) laser pulse energy and intrinsic efficiency values comparable to those of UV rare gas-halide lasers. Herein we report measurements of transient absorption confirming that the primary effect of a buffer comprised of Ar and Kr is a significantly lower level of ionized and excited species that absorb in the blue-green spectral region. Spectral analysis of a variety of mixtures shows that the Ar-Kr buffer also benefits XeF(C rightarrow A) laser performance due to an increase in gain in the 400-450 nm region caused by the presence of the Kr2F excimer. In addition, a large increase in absorption at ∼ 351 nm, also due to Kr2F, suppresses oscillation on the competitive XeF(B rightarrow X) transition and, for certain conditions, makes efficient simultaneous oscillation of the XeF(B rightarrow X) and XeF(C rightarrow A) laser transitions possible.     

Theoretical simulation of electron-beam-excited xenon-chloride (XeCl) lasers

By developing a comprehensive computer code fore-beam excited XeCl lasers, we studied mainly the effect of Ar and Ne diluents on the performance characteristics of XeCl lasers. According to the analysis of the XeCl* formation process, the XeCl* relaxation process, and the 308 nm absorption process, it is found that the XeCl* formation efficiency is determined mainly by the rate of the charge transfer process (from Ar+ and Ne+ diluent ions to Xe+); in other words, by the difference between ionic potentials of Xe and the diluent gas used. The extraction efficiency is found to be decided mainly by the quenching rate of a three-body reaction for a short-pulse (55 ns) and a high-excitation-rate (∼ 3 MW/cm³) pumping, and by the absorption process for a long-pulse (500 ns) and a low-excitation-rate (∼ 0.2 MW/cm³) pumping. However, note that no appreciable difference in the intrinsic efficiency is found between the Ar/Xe/HCl and Ne/Xe/HCl mixtures. We also analyzed the dependence of the intrinsic XeCl laser efficiency on the pumping pulse width and excitation rate for Ar/Xe/HCl and Ne/Xe/HCl mixtures. As a result, the same intrinsic efficiencies are obtainable for both Ar- and Ne-based mixtures although the optimum operating conditions are slightly different. The maximum intrinsic efficiency of 5 percent is obtainable both for the Ar/Xe/HCl mixture at 3 atm and with 1.5 MW/cm³, 200 ns (FWHM) pumping and for the Ne/Xe/HCl mixture at 4 atm and with 2 MW/cm³, 200 ns (FWHM) pumping.     

通过优化工作气体分压提高准分子激光器脉冲能量输出

分别研究了Kr和F2对KrF准分子激光器脉冲能量输出的影响。脉冲能量输出对F2分压的变化非常敏感,并与Kr分压呈二次函数关系。在最优化工作气体分压（F2:He:Kr:Ne=3.15:59.85:195:3050mbar）下,获得了807mJ最大单脉冲输出能量。这个气体成份下的全电效率为1.64%。     

Xe矩阵晶体中准分子Xe_2~＋Cl~－跃迁辐射能量计算

本文计算了Ｘｅ掺杂Ｃｌ矩阵晶体中经激光辐照形成的离子准分子Ｘｅ２＋Ｃｌ－体系的能量。由于极化和与固态Ｘｅ原子的色散相互作用，其能量与气体中的不同。计算表明Ｘｅ２＋Ｃｌ－准分子电子态跃迁对应于实验观测到的辐射。     

Ion laser plasmas

The typical noble gas ion laser plasma consists of a high-current-density glow discharge in a noble gas, in the presence of a magnetic field. Typical CW plasma conditions are current densities of 100 to 2000 A/cm², tube diameters of 1 to 10 mm, filling pressures of 0.1 to 1.0 torr, and an axial magnetic field of the order of 1000 G. Under these conditions the typical fractional ionization is about 2 percent and the electron temperature between 2 and 4 eV. Pulsed ion lasers typically use higher current densities and lower operating pressures. This paper discusses the properties of ion laser plasmas, in terms of both their external discharge parameters and their internal ion and excited state densities. The effect these properties have on laser operation is explained. Many interesting plasma effects, which are important in ion lasers, are given attention. Among these are discharge nonuniformity near tube constrictions, extremely high ion radial drift velocities, wall losses intermediate between ambipolar diffusion and free fall, gas pumping effects, and radiation trapping. The current status of ion laser technology is briefly reviewed.     

Ultraviolet ion laser performance and spectroscopy--Part I: New strong noble-gas transitions below 2500 Å

The performance and spectroscopy of UV ion lasers have been investigated to 1850 Å, the limit of available mirrors. New anomalously strong transitions of about 1-kW peak power were found in Xe IV? at 2315.357 Å and Kr IV at 2191.916 Å. The shortest wavelength new laser transition was Kr IV at 1949.623 Å. Wavelengths were measured for 25 new and many previously known UV laser transitions to about 0.006 Å. Optimum output in watts was also measured as a function of bore current density and gas pressure. All measurements were taken from a 7-mm-bore 150-cm-arc-length tube designed for low electrical inductance providing current excitation pulses with 250-ns full width at half maximum (FWHM).     

Nonlinear optical processes in atoms and molecules using rare-gas halide lasers

The use of nonlinear optical processes expands the flexibility of excimer systems in the study of a wide range of atomic and molecular phenomena and materials. These mechanisms have already allowed for the selective excitation of states in the 10 to 20 eV range involving bound state excitation, ionization, and molecular dissociation. Specific examples involving the electronic excitation of H2, Kr, and Xe, the production of Xe⁺for the analysis of the molecular properties of XeF*, and nonlinear photodissociation of N2O and OCS are discussed.