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为更好地理解低气压、弱电离条件下潘宁离子源放电过程中离子和电子的动力学行为, 通过建立二维轴对称模型, 采用粒子模拟与蒙特卡罗相结合(PIC/MCC)的方法, 考虑了电子与氢气之间的弹性碰撞、激发、电离以及氢原子、离子之间的弹性碰撞和电荷交换等过程, 对微型氢气潘宁离子源放电和引出过程进行了数值研究. 考察了磁场位形、壁面二次电子发射系数、引出电压和充气压力对放电过程的影响, 得到了实验中难以诊断得到的放电腔内电子与离子数密度分布, 阳极电流、引出极离子电流、单原子氢离子比例和双原子氢离子比例等宏观参数与实验结果相一致. 通过仿真使得对氢气潘宁放电机制的研究从定性过渡到定量, 这对于潘宁离子源的设计和改进具有重要意义.
关键词:
潘宁放电
氢气
粒子模拟
蒙特卡罗 相似文献
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Noble gas ionization detectors make it possible to determine inorganie trace components in gases. Among the several modes of operation of these detectors the hydrocarbon-sensitized argon detector is a farourable compromise with regard to the relation of the expense to the attainable detection limit. The suitability of this detector for the determination of H2, O2, N2, CH4 and CO2, in pure gases is shown. 相似文献
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AbstractThe dependence of calcium and sodium matrix effects on the total excitation energy of analyte emission signals was used as a tool for the study of excitation mechanisms in radial view mode inductively coupled plasma optical emission spectroscopy. A total of 95 atomic and 66 ionic emission signals of aluminum, cobalt, chromium, iron, magnesium, manganese, nickel, and silicon in the 3.0–17.59?eV energy range were measured at the non-robust plasma operating conditions to facilitate the matrix effect study. Different matrix effects versus total excitation energy relationships were observed regarding the energy interval. The change of sign from negative to positive of the both matrix effect versus total excitation energy relationship observed around 14?eV, in the 12.06–17.59?eV energy range, is interpreted as experimental evidence of the action of two non-thermic excitation mechanisms: Penning ionization from approximately 12 to 14?eV and charge transfer from 14 to 17?eV. Based on the energy resonance principle and total spin conservation Wigner’s Theorem, possible reactions between excited ionic argon and ground state analyte ions were proposed. 相似文献
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表面强化技术可以显著提高材料的疲劳性能,广泛应用于航空零部件的加工制造。在试验研究强化工艺对材料疲劳性能的增强效果时,常采用升降法来进行。针对升降法试验中存在的初始应力不易确定的问题,根据线性累积损伤理论和已知表面强化前材料疲劳特性的特点,提出一种快速确定升降法试验初始应力的方法,应用于K417材料激光冲击强化效果试验验证中。该方法仅需通过2~3个试件的实验即可找到适当的初始应力。通过对不同表面状态标准试片的振动疲劳试验,验证了激光冲击强化可较大幅度增强材料的疲劳性能。 相似文献
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K. Blaum D. Beck G. Bollen P. Delahaye C. Guénaut F. Herfurth A. Kellerbauer H.-J. Kluge U. Köster D. Lunney S. Schwarz L. Schweikhard C. Yazidjian 《Hyperfine Interactions》2005,162(1-4):173-179
We have demonstrated for the first time that element-selective laser ionization in combination with ultra-high resolution
mass spectrometry can be used to prepare isomerically pure ion ensembles. Together with β–γ coincidence studies this method allowed a determination of the low-energy structure and the unambiguous identification of
triple β-decaying isomerism in 70Cu. By selective resonant ionization and measurement of the masses of these three states using ISOLTRAP at ISOLDE/CERN with
a relative uncertainty of δm/m ≈ 5 ⋅ 10−8 a clear state-to-mass assignment was possible which resolved the assignment puzzle in 70Cu. 相似文献
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根据Penning阱存储离子的探测原理,系统分析了阱内离子信号及信号本身的噪声、实验仪器及探测电路的噪声干扰,采用适当的品质因数和电子束流,得到较高信噪比和分辨率的离子谱。为深入开展Hn^+(n≥3)对离子的形成机制、离子与中性气体原子或分子碰撞过程等问题的研究创造了更好的条件。 相似文献
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Penning阱存储离子的灵敏探测 总被引:2,自引:1,他引:1
对Penning阱中存储离子的探测原理和技术进行了研究,得到了较高探测灵敏度和较高信器比的H+n(n=1,2,3,4)离子谱,为开展离子与中性气体原子(或分子)碰撞过程等课题的研究创造了条件。 相似文献
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Mohamed A. Mahmoud 《Central European Journal of Physics》2008,6(3):530-538
We have studied the formation of the molecular ion Rb2+ and the atomic ion Rb+. These are created in laser excited rubidium vapor at the first resonance, 5s–5p and 5p-nl transitions. A theoretical model
is applied to this interaction to explain the time evolution and the laser-power dependence of the population density of Rb+ and Rb2+. A set of rate equations which describe: the temporal variation of the population density of the excited states; the atomic
ion density; and the electron density, were solved numerically under the experimental conditions of Barbier and Cheret. In
their experiment the Rb concentration was 1×1013cm−3 and the laser power was taken to be 50–500 mW at vapor temperature = 450 K. The results showed that the main processes for
producing Rb2+ are associative ionization and Hornbeck-Molnar ionization. The calculations have also showed that, the atomic ions Rb+ are formed through the Penning Ionization (PI) and photoionization processes. Moreover, a reasonable agreement between the
experimental results and our calculations for the ion currents of the Rb+ and Rb2+ is obtained.
相似文献
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Stereoselectivity in Autoionization Reactions of Hydrogenated Molecules by Metastable Noble Gas Atoms: The Role of Electronic Couplings 下载免费PDF全文
Prof. Stefano Falcinelli Prof. Marzio Rosi Prof. Simonetta Cavalli Prof. Fernando Pirani Prof. Franco Vecchiocattivi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(35):12518-12526
Focus in the present paper is on the analysis of total and partial ionization cross sections, measured in absolute value as a function of the collision energy, representative of the probability of ionic product formation in selected electronic states in Ne*?H2O, H2S, and NH3 collisions. In order to characterize the imaginary part of the optical potential, related to electronic couplings, we generalize a methodology to obtain direct information on the opacity function of these reactions. Such a methodology has been recently exploited to test the real part of the optical potential (S. Falcinelli et al., Chem. Eur. J., 2016 , 22, 764–771). Depending on the balance of noncovalent contributions, the real part controls the approach of neutral reactants, the removal of ionic products, and the structure of the transition state. Strength, range, and stereoselectivity of electronic couplings, triggering these and many other reactions, are directly obtained from the present investigation. 相似文献