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Design and study the effect of inner bore diameter on the magnetic and optical properties of the unipolar lens

Authors

  • Mohammed.K.A. AL- Janan Department of physics, College of Science, University of Tikrit, Salahaddin, Iraq. https://orcid.org/0000-0001-7546-2793
  • R.Y. J. AL-Salih Department of physics, College of Science, University of Tikrit, Salahaddin, Iraq.

DOI:

https://doi.org/10.21123/bsj.2022.7075

Keywords:

Chromatic aberration, Magnetic lens, Optical aberration, Resolving power, Spherical aberration

Abstract

    Many designs have been suggested for unipolar magnetic lenses based on changing the width of the inner bore and fixing the other geometrical parameters of the lens to improve the performance of unipolar magnetic lenses. The investigation of a study of each design included the calculation of its axial magnetic field the magnetization of the lens in addition to the magnetic flux density using the Finite Element Method (FEM) the Magnetic Electron Lenses Operation (MELOP) program version 1 at three different values of current density (6,4,2 A/mm2). As a result, the clearest values and behaviors were obtained at current density (2 A/mm2). it was found that the best magnetizing properties, the highest value of magnetic flux, the lowest value of band width of the axial magnetic field strength had been obtained when the width of the inner cavity was of (55 mm). The effect of current density on the optical properties has also been studied, the chromatic and spherical aberration values have been decreased significantly. Thus, lens was chosen as the best design among the proposed designs unipolar lens.

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References

Sultan S, Alabdullah A, Abdel Azeez A. Effect of Pole Face Thickness on Magnetization of the Single-pole Magnetic Lens. Rafidain J Sci.2020; 29 (4): 44-52.

Yassin S, Mohammed A, Space-Charge Effect on the Theoretical Design of Electron Gun Operated under Zero Magnification Condition. Baghdad Sci J. 2014;11(2) :572-576.

Hawkes P W. Recent advances in electron optics and electron microscopy. ISO4.2004 ;29 (1): 837-855.

Mohammed I Design of six electrode Enzial electrostatic lens low aberrations for electron gun. Baghdad Sci J. 2010;7 (3) :1127-1131.

Bogner A, Juneau P, Tolled H, Basset G, Gauthier C. history of scanning electron microscopy: Towards wet-STEM imaging Micron. 2007; 38: 390–401.

Abbas T, Sahi Q. Design and study of optical properties of electromagnetic symmetric dipole lenses using (EOD) program. JUBPAS. 2017; 25 (6) :1991-1997. https://www.journalofbabylon.com/index.php/JUBPAS/article/view/295

El-Shahat S, Al Amir A, Hassan G, Studies on the effect of pole piece shape for saturated single pole magnetic lens, Proceedings of the 1st International Conference on New Ho-rizons in Basic and Applied Sci, Hurghada-Egypt. 2013; 1 (1) : 290–298.

Numan N, Theoretical Study of Geometrical Properties and Aberrations in Doublet Magnet Lenses, J Univ Babylon Eng Sci, 2018;26 (8) :178-187. https://www.journalofbabylon.com/index.php/JUBES/article/view/1596

Plies E, Modren Electron Optics in SEM and Inspection"., Proceedings of the 12th European Congress on Electron Microscopy. 2000; 3: 1423-1425. https://www.tib.eu/en/search/id/TIBKAT%3A318631741/Proceedings-of-the-12th-European-Congress-on-Electron/

AL-Salah R, Al-Abdulla A, Alkattan E, Simple program for computing objective optical properties of magnetic lenses, Int J Comput Appl Tec. 2022; 66 (3-4): 254-259.

Weninger C, Baum P, Temporal Distortion in Magnetic Lenses. Ultramicroscopy. 2012; 113: 145-151.

Al-Shamma M, Al-Khashab M. Improvement of the Optical Performance of the Geometrical Parameters of Snorkel Magnetic Lens. Raf J Sci 2019; 28 (1) :85-97.

Egerton R. Physical Principle of Electron Microscopy.Springer: An Introduction to TEM, SEM, and AEM 7 Ed, ISBN.2005

Oday H, Fatin J, Fatma N. Investigation of the Optical Properties of the Achromatic Quadrupole Lens by Using the Rectangular Potential Distribution Model. Um-Salama Sci J, 2009; 6(2) :386-393.

Hasan S, Obaid S, Erhayial M. Recent Development-2 of CADTEL Software the Optimum Conditions of Scherzer Imaging in the Electron Magnetic Lenses. Iraqi J Sci. 2022 63(1): 131-148

Wasan J Kadhem, Ban A Naser, Talib M. Abbas. Optimization of asymmetrical magnetic lenses with the aid of EOD program. Int J Eng Technol. 2018; 7(4): 3591-3594.

Etienne Gagnon, Nana Kwame Owusu, Amy L Lytle. Time evolution of the Coulomb screening effects on terahertz generation at the surface of InAs. J Opt Soc Am B. 2016;33 (3); 367-372.

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