共查询到19条相似文献,搜索用时 194 毫秒
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详细研究了CuBr激光充氢后的激光动力学过程,解释了实验中观测到的两个现象:1)充氢后功率增大,其主要原因是:充氢使中心气体温度和CuBr分子蒸汽密度降低,从而减少了电子碰撞离解CuBr的有量损耗,导致电子温度上升。同时,脉冲期间的电子密度增加,电子密度的趋肤效应减弱,激光的“黑心”现象被改善。2)存在一个最佳充氢范围,其原因是:充氢后,随着气体温度的进一步降低,电子温度和铜原子度也将下降,它们与 相似文献
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在边界等离子体中,氢分子具有相当高的密度,这些分子与等离子体发生碰撞可使氢分子的振动分布发生变化.本文讨论氢分子的行为,采用了最新的截面数据,对于文献中尚无可利用的截面,运用半经典的Gryzinski方法进行计算.基于准静态近似和准稳态碰撞辐射模型对氢及其同位素分子D2和T2的振动分布进行了研究.结果表明:当电子温度低于10 eV时,氢及其同位素分子的振动分布在较低的振动能级随着电子温度的升高而减小;而在较高的振动能级,分布则呈现相反趋势. 相似文献
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详细讨论了封离型CO2激光器中CO2,N2和He三混合气体含量被优化组合后的激光动力学机理.气体优化可以提高激光输出功率的主要机理是通过适当增加N2含量,使N2激发态与CO2激光上能级的碰撞频率增加,提高了激光能级粒子数密度和相对布居数.同时,适当减少CO2含量,使总的电子动量输运碰撞频率减小、放电电流增大,导致增加激光上转动能级的弛豫速率和减小能级寿命,从而提高了谐振腔内的激光饱和光强. 相似文献
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详细讨论了封离型CO2激光器中CO2,N2和He三混合气 体含量被优化组合后的激光动力 学机理. 气体优化可以提高激光输出功率的主要机理是通过适当增加N2含量, 使N2激发 态与CO2激光上能级的碰撞频率增加,提高了激光能级粒子数密度和相对布居数 . 同时, 适当减少CO2含量,使总的电子动量输运碰撞频率减小、放电电流增大,导致增 加激光上转动能级的弛豫
关键词:
2激光')" href="#">CO2激光
气体动力学
强化机理 相似文献
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使用朗谬尔探针方法研究了低压CF4气体感应耦合等离子体(ICP)的放电特性.结果表明 ,CF4等离子体的电子呈现双温分布:一类是密度低、能量高的快电子,另一类是密度高 、能量低的慢电子.快电子温度The、慢电子温度Tce以及它们的平均 电子温度Te随射频输入功率的增加而下降;而它们的密度nhe,nce和ne随功率的增加而上升.从电子与气体粒子碰撞能量平衡的角度解释了双温电子特性与射频输入功率之间的关系.
关键词:
感应耦合等离子体
CF4气体
朗谬尔探针
电子温度 相似文献
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A mathematical model describing the discharge kinetics and lasing characteristics of copper bromide vapor laser with neon and hydrogen additives has been developed. The suggested model is based on a “zero-dimensional” model and offers simple mechanisms to explain discharge kinetics mechanisms, different physical processes and hydrogen additive effects on the copper bromide vapor laser.The model estimates the temporal evolution of discharge voltage and current, population densities, laser beam density, electron temperature and radial distribution of pressure and buffer gas temperature. The suggested mechanism assumes that the electron detachment from negative hydrogen ions does not contribute to the copper ionization process.Numerical solutions of a nonlinear rate equation system predict the generation of nanosecond pulses. The calculated maximum values of discharge voltage, current, average output laser power, electron temperature, etc. are in good agreement with other reported calculated and experimental data. 相似文献
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Development of master oscillator power amplifier (MOPA) system of copper bromide laser (CBL) operating at 110 W average power is reported. The spectral distribution of power at green (510.6 nm) and yellow (578.2 nm) components in the output of a copper bromide laser is studied as a function of operating parameters. The electrical input power was varied from 2.6 to 4.3 kW, the pulse repetition frequency (PRF) was changed from 16 to 19 kHz, and the pressure of the buffer gas (neon) was kept fixed at 20 mbar. When the electrical input power was increased to 4.3 kW from 2.6 kW, the tube-wall temperature also increased to 488°C from 426°C but the ratio of the green to yellow power decreased to 1.53 from 3.73. The ratio of green to yellow power decreased to 1.53 from 1.63 when the PRF of the laser was increased to 19 kHz from 16 kHz. These observations are explained in terms of electron temperature, energy levels of transitions, and voltage and current waveforms across the laser head. 相似文献
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A wide-aperture copper vapour laser was demonstrated at ∼10 kHz rep-rate with hydrogen additive in its buffer gas. Maximum
power in excess of ∼50 W (at 10 kHz) was achieved by adding 1.96% hydrogen to the neon buffer gas at 20 mbar total gas pressure.
This increase in output power was about 70% as compared to ∼30 W achieved with pure neon at 5.5 kHz rep-rate. The 70% enhancement
achieved was significantly higher than the maximum reported value of 50% so far in the literature. The enhancement was much
higher (about 150%) as compared to its 20 W power at 10 kHz rep-rate using pure neon as the standard CVL operation. 相似文献
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Hernqvist K. G. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1978,6(3):238-243
A performance analysis is presented for the hydrogen dissociator used in hydrogen masers to provide a beam of atomic hydrogen. An analysis of the discharge characteristics yields relations for electron temperature as a function of vessel size and gas pressure and for plasma density as a function of power input. Also a relation between ion impact energy at the wall and electron temperature is derived. For a typical dissociator (2" diameter, 0.1 Torr hydrogen pressure, and 4 watt input power) these relationships yield an electron temperature of 39,000°K, a plasma density of 1011 cm-3 and an ion impact energy of 20 volts. The dissociation rate is calculated using published cross-sections. Assuming a recombination rate of 4 × 10-3, the analysis yields an atomic hydrogen density of about 1014 cm-3, a degree of dissociation of 2%, and an atomic beam flux of 1.3 × 1018 cm-2 × sec-1 for the example quoted. This beam flux is in good agreement with estimated values for hydrogen masers. A coefficient for performance ? is derived for the hydrogen dissociator, defined as the ratio of atomic beam flux to discharge power consumption. It is shown that ? is a function of the electron temperature and has a maximum at 87,000°K. It is concluded from this analysis that the discharge in presently used hydrogen dissociators is well optimized given the pressure constraints of the system. 相似文献
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B.L. Pan G. Chen B.N. Mao T.T. Xia Z.X. Yao 《Applied physics. B, Lasers and optics》2006,82(2):295-297
A small-size discharge heated barium vapor laser with an axial temperature controller was designed and made. The operational
characteristics of the laser with different hydrogen additives and two excitation circuits were experimentally investigated
and compared. The results indicate that the addition of a small ratio (1.5%) of hydrogen to neon and the interactive circuit
(IC) can greatly increase the laser output power. The maximum average laser power of 3.5 watts and a record specific power
of 117.3 mW/cm3 at a 1.5 μm wavelength were obtained under optimal discharge conditions. Some possible mechanisms were suggested to explain
the enhanced effect of the hydrogen additive and IC to the laser output performances.
PACS 42.55.Lt; 42.60.Lh; 52.80.Tn 相似文献
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E. A. Kralkina P. A. Nekliudova V. B. Pavlov K. V. Vavilin 《Moscow University Physics Bulletin》2014,69(1):92-95
This paper presents the results of investigating the power absorption mechanism of an inductive RF discharge plasma. Dependences of the frequency of elastic electron collisions with inert gas atoms (helium, neon, argon, and krypton) on the pressure are given. In the frequency range of 3 × 106–3 × 107 s?1, an equivalent plasma resistance and the power input into the plasma are determined by the values of collision frequency and electron density within a skin layer and do not depend on the type of gas within the limits of experimental error. Upon reaching the electron temperature of ~1 eV, the energy of the main part of electrons lies in the range of Ramsauer’s minimum for elastic cross section. This leads to a decreasing elastic-collision frequency in heavy inert gases as compared to helium. 相似文献
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Abstract A 27.12 MHz low flow (3 1/min), laminar flow, atmospheric pressure neon ICP has been generated. The forward power used is 500 W with a reflected power of less than 5 W. Using higher powers caused the plasma to either extinguish or form numerous filaments. The Hß line is used to determine an electron number density of 8 × 1013cm?3. The N2 +(0, 0) and OH(0, 0) transitions did not readily emit. This fact, coupled with the low electron density and low input power, indicates a relatively cool plasma. 相似文献
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对用Blumlein电路放电激励的钡蒸气激光在掺氢和不掺氢时的输出特性进行了实验研究.结果表明,用掺氢1.5%的氖气作缓冲气体能使激光功率增加近2倍.在此基础上,进一步比较了相互作用电路与Blumlein电路时钡蒸气激光的输出特性,发现相互作用电路能显著提高钡蒸气激光的输出功率和效率,获得了3W最大功率和0.4%效率的1.5μm波长激光输出.测量并分析了各工作参量与激光功率之间的关系,定性解释了掺氢与相互作用电路的作用机理 .
关键词:
Blumlein电路
相互作用电路
掺氢
钡蒸气激光 相似文献
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利用螺旋波等离子体化学气相沉积(HWP-CVD)技术,以氢气为反应气体产生等离子体。通过采集氢的可见到紫外发射光谱,对等离子体进行了原位诊断,由氢Balmer系分析得到了不同实验参数对激发态氢原子相对密度的影响,通过对Fulcher带的分析,得到实验参数对氢振动温度的影响。结果表明:低压氢等离子体状态可借用日冕模型来诊断;激发态氢原子密度随入射功率增加而增加,随压强增加而减少,氢分子振动温度随压强增加先增大后减小;电子温度和电子密度是低压氢等离子体状态变化的关键因素。 相似文献