Optimization of asymmetrical magnetic lenses with the aid of EOD program

  • Authors

    • Wasan J. Kadhem
    • Ban A. Naser
    • Talib M. Abbas
    https://doi.org/10.14419/ijet.v7i4.21739

  • A common method used for the design of magnetic lenses is the analysis optimization procedure that using the finite element method with the aid of the Munro programs. The latter way has been applied in the present work to investigate asymmetrical magnetic lenses in conjunction with Electron Optical Design software( EOD). The influence of two important geometrical parameters, namely the axial bore diameter and the air gap, on the objective and projector properties. Our results show that all of the optical properties has been studied minutely are improved at the lowest values of these two parameters.

  • References

    1. [1] Moses, R.W. Lens Optimization by Direct Application of the Calculus of Variation. Image Processing and Computer Aided Design in Electron Optics, ed. P.W. Hawkes (Academic Press). (1973)250-272.

      [2] Wasan J. Kadhem, Hassan N. Al-Obaidi. An Inverse Design Approach For Magnetic Lenses Operated Under Infinite Magnification Condition. Optik 124 (2013)3523-3526. https://doi.org/10.1016/j.ijleo.2012.12.001.

      [3] Wasan J. Kadhem. Obtaining doublet magnetic lenses by synthesis technique. Optik 126 (2015) 4066-4071. https://doi.org/10.1016/j.ijleo.2015.07.204.

      [4] Kamminga, W. Properties of Magnetic Objective Lenses with Highly Saturated Polepieces. Optik 45(1976)39-54.

      [5] Tsuno, K. and Harada, Y., Elimination of Spiral Distortion in Electron Microscopy Using an Asymmetrical Triple-Polepiece Lens. J. Phys. E: Sci. Instrum, 14 (1981b) 955-959. https://doi.org/10.1088/0022-3735/14/8/015.

      [6] Tsuno, K. and Honda, T., Magnetic Field Distribution and Optical Properties of Asymmetrical Objective Lenses For an Atomic Resolution High Voltage Electron Microscope. Optik 64 (1983) 367-78.

      [7] Zeitler, E., Analysis of an Imaging Magnetic Energy Filter, Nucl. Inst. Meth. Phys. Res. A, 298 (1990) 234-246. https://doi.org/10.1016/0168-9002(90)90621-C.

      [8] Szilagyi, M., Reconstruction of Electron and Polepiece From Optimized Axial Field Distribution of Electron and Ion Optical System. Appl. Phys. Lett., 45 (1984) 499-501. https://doi.org/10.1063/1.95315.

      [9] Szilagyi, M., Synthesis of Electron and Ion Optical Columns, J. Vac. Sci. Technol. 9 (1991) 2618-2621. https://doi.org/10.1116/1.585659.

      [10] Preikszas, D. and Rose, H., Procedures For Minimizing The Aberrations of Electromagnetic Compound Lenses, Optik 100 (1995) 179-187.

      [11] Lencova, B., Accurate Computation of Magnetic Lenses with FOFEM. Nucl. Inst. In addition, Meth. Phys. Res. A, 427 (1999) 329-337.

      [12] Juma, S. M., and Yahya, A. A., Focal Properties of Unsaturated Asymmetrical Magnetic Electron Lenses. J. Phys. E: Sci. Instrum., 19 (1986) 614-624. https://doi.org/10.1088/0022-3735/19/8/007.

      [13] Tsuno, K. and Honda, T., Magnetic Field Distribution and Optical Properties of Asymmetrical Objective Lenses For an Atomic Resolution High Voltage Electron Microscope. Optik 64 (1983)367-78.

      [14] Munro, E., A set of Computer Programs for Calculating the Properties of Electron Lenses. University of Cambridge, Department of Engineering Report CUED/B-Elect. TR 45 (1975).

      [15] Lencova, B. Software for particle optics computation, http://www.lencova.com. 2009.

      [16] Munro, E., Computer-Aided Design of Electron Lenses by the Finite Element Method. Image Processing and Computer-Aided Design in Electron Optics, ed. P. W. Hawkes (Academic Press) (1973) 284-323.

      [17] Szilagyi, M., Electron and Ion Optics, (Plenum Press: New York). (1988). https://doi.org/10.1007/978-1-4613-0923-9.

      [18] Lence, M. and Lencova, B., Saturated Single Polepiece Objective Lenses. Electron Microscopy, 1984 eds., A Csanady, R. Rohlich and Szaba (Programme Committee of the Eighth European Congress on Electron Microscopy, Budapest) (1984) 27-8.

      [19] Tsuno, K. and Harada, Y., Minimization of Radial and Spiral Distortion in Electron Microscopy Through The Use of A Triple-Polepiece Lens, J. Phys. E: Sci. Instrum., 14 (1981a) 313-319. https://doi.org/10.1088/0022-3735/14/3/013.

      [20] Hawkes, P. W., Magnetic Electron Lenses. (Springer-verlag). (1982). https://doi.org/10.1007/978-3-642-81516-4.

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  • How to Cite

    Kadhem, W. J., Naser, B. A., & Abbas, T. M. (2018). Optimization of asymmetrical magnetic lenses with the aid of EOD program. International Journal of Engineering & Technology, 7(4), 3591-3594. https://doi.org/10.14419/ijet.v7i4.21739