共查询到18条相似文献,搜索用时 171 毫秒
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在电子和离子光学理论(特别是象差理论)中,广泛地应用了矩阵的运算方法。本文讨论了旋转对称电子光学系统与重叠场(环形电场与非均匀磁场的叠加)离子光学系统中存在初级象差下的变换矩阵,证明了这些变换矩阵的行列式数值恒为1.这个普遍结论是刘维定理的具体应用。这对于电子和离子光学象差理论及计算机辅助设计具有一定意义。
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本文描述一种具有大显象场的全息光学干涉仪。它达到了干涉仪的象差校正,并制成热流无象差干涉图。100mm显象场的干涉仪可用于研究透明介质。 相似文献
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电子和离子光学的研究范畴是带电粒子在电磁场中聚焦、成象、偏转等的规律。它的理论基础是经典力学、经典电动力学和光学.它依据带电粒子在电磁场中运动与光线在光学媒质中传播之间的相似性,运用类似于光学的方法和概念(例如费马原理、光程函数、折射率、射线、透镜和象差等)形成自己的理论体系.在二、三十年代,电子和离子光学开始发展.现在电子和离子光学已渗透到无线电电子学、电子和离子显微学、质谱学、固体物理和表面物理、材料科学、高能加速器物理和等离子体物理等许多学科领域中. 电子和离子光学包括如下几个主要方面:1.旋转对称成… 相似文献
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本文研究了旋转对称磁透镜和磁偏转器的复合系统,给出了场和轨迹的普遍表达式。利用向量形式来描写电子轨迹,讨论了高斯光学性质。运用变分原理(费马原理)计算了三级象差,得出了复合系统普遍的象差公式。它们以矩阵的形式表出,形式简洁,便于进行数值计算。本文的结果具有较大的普遍性,概括了文献上关于偏转象差的已有结果,并对复合系统作了较完整的论述和严格的计算,因而可以广泛地研究各种电子束管和电子光学仪器的偏转象差。 相似文献
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近来磁六极透镜作为球差校正器引起了人们的注意。本文研究了磁圆形透镜和磁六极透镜的场分布叠加形成的复合系统的象差。我们在复数域中定义了内积,采用了复数的表象和微分算符,全面讨论了这种复合系统的高斯光学性质及二、三、四级象差,得出了各级象差所有的象差系数的公式。
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本文将文献[1]的方法和结果加以推广,研究了旋转对称静电透镜和磁偏转器的复合系统。给出了场和轨迹的普遍表达式,讨论了高斯光学性质,得出了这种系统普遍的三级象差和象差系数的公式。这两篇文章有助于较全面地研究各种电子束管和电子光学仪器的偏转象差。
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Abstract To improve performances of mass spectrometers dedicated to isotopic or chemical analysis, the methods of the ion optics are to be used. To apply the transfer matrix method of ion optics in mass spectrometer design, the matrix elements of various mass analyzers as Wien filters and crossed field sectors, of energy analyzers as electric prisms, were presented. These elements result from ion trajectory calculations representing solutions of the Euler–Lagrange equations. The basic parameters of an unconventional double focusing mass spectrometer were calculated and compared with those of classical design instruments. 相似文献
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介绍了一种改进的反射式飞行时间质谱装置用于光解质量选择的团簇离子. 该装置中采用了\选质-减速-解离-再加速"的方式. 团簇离子在反射式飞行时间的一级聚焦点被选质,接着被减速,并且立即被光解,光解所产生的碎片以及没有被光解的母体离子被重新加速,这一系列过程都在靠近一级聚焦点的位置完成. 相对文献中报道的其他方式,采用这一方式更利于光解碎片和母体离子的分离,更容易确定光解激光的触发时间,同时,由于母体离子在一级聚焦点的空间分布比较窄,也有利于光解激光束照射到所有的团簇离子,从而提高光解效率. 对母体离子、碎 相似文献
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简要阐述了求解离子光学系统电场结构分布以及带电粒子在该电场中运行轨迹的通用数值计算方法,分析了在保证计算精度的前提下,节省磁盘空间、提高计算速度的PC级计算机上优化算法,并提出一种寻找最佳超松弛因子的可行性方法.在PC级计算机上应用该计算方法对一台无栅网结构高分辨率反射式飞行时间质谱仪进行计算,给出了电场分布、粒子飞行轨迹和设定各种不同条件对电场进行优化的结果.根据计算结果调整的反射式飞行时间质谱仪达到了其优化工作状态,所测得的质谱分辨率显著提高. 相似文献
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Designs of a quadrupole ion trap (QIT) as a source for time-of-flight (TOF) mass spectrometry are evaluated for mass resolution, ion trapping, and laser activation of trapped ions. Comparisons are made with the standard hyperbolic electrode ion trap geometry for TOF mass analysis in both linear and reflectron modes. A parallel-plate design for the QIT is found to give significantly improved TOF mass spectrometer performance. Effects of ion temperature, trapped ion cloud size, mass, and extraction field on mass resolution are investigated in detail by simulation of the TOF peak profiles. Mass resolution (m/Δm) values of several thousand are predicted even at room temperature with moderate extraction fields for the optimized design. The optimized design also allows larger radial ion collection size compared with the hyperbolic ion trap, without compromising the mass resolution. The proposed design of the QIT also improves the ion-laser interaction volume and photon collection efficiency for fluorescence measurements on trapped ions. 相似文献
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Cation and anion formation is studied experimentally upon inelastic low
energy electron interactions with 5-bromouridine (BrUrd) using a crossed
electron/neutral beams set-up combined with a quadrupole mass spectrometer.
The BrUrd molecule belongs to the class of radiosensitizers that increase
the sensitivity of DNA (or RNA) to ionizing radiation. In the case of
positive ion formation the ionization efficiency curves are measured near
the threshold and the corresponding appearance energies are determined using
a non-linear least square fitting procedure. The anion yields are
investigated in the electron energy range from about 0 to 14 eV. From the
comparison of the present results for negative and positive ions information
concerning the underlying mechanism of radiosensitizers is deduced. 相似文献
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The equations of motion for a charged particle in crossed magnetic and electric fields are used to make a numerical simulation
of the operation of a magnetic resonance mass spectrometer for which the ion trajectory in the analyzer is divided into various
sections. The calculations take into account the real structural dimensions and the parameters of the main components and
systems and also allow for its operating characteristics in various regimes, as obtained by investigating a prototype. The
calculation s yield the optimum geometric, electrical, frequency, phase, and magnetic parameters of the device, for which
one can achieve a resolution R
5096≈1.35×106 and a current efficiency K
I
≈0.006.
Zh. Tekh. Fiz. 69, 89–96 (April 1999) 相似文献
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A. I. Boriskin V. M. Eremenko S. N. Mordyk O. R. Savin A. N. Skripchenko V. E. Storizhko S. N. Khomenko 《Technical Physics》2008,53(7):927-933
The ion-optical systems of a mass spectrometer with a laser ion source and coordinate-sensitive microelectronic detector are analyzed using the matrizant method. The dispersion properties of the mass spectrometer, as well as ion beam radial and axial focusings in its optimized ion-optical system, are determined, and first-and second-order angular and velocity aberrations of the image are corrected. The basic parameters and characteristics of a refined (according to calculation results) version of the laser mass spectrometer with a coordinate-sensitive microelectronic detector are presented. 相似文献