caa a22 4500 39756967X CHVBK 20180308164837.0 cr unu---uuuuu 161202e199610 xx s 000 0 eng 10.1093/oxfordjournals.jmicro.a023454 doi (NATIONALLICENCE)oxford-10.1093/oxfordjournals.jmicro.a023454 Optimization of Operating Conditions for the FE Gun System of HVEM [Elektronische Daten] [Chiaki Morita, Toshimi Ohye, Hiroshi Shimoyama] Numerical calculations have been conducted on the electron optical characteristics of the field-emission (FE) gun system of the high-voltage electron microscope, which consists of an FE gun, an accelerating tube (AT) and a transfer lens placed between them. Emitted electrons are firstly accelerated to V0 by the FE gun and, finally, to Va by the AT, which includes 34 stages of accelerating electrodes and has an overall length of 1,423 mm. The AT is equipped with a retarding field between the first and second electrodes, and operates as a thick electrostatic lens. The spherical aberration coefficient of the AT lens was calculated as a function of the object position, i.e. the crossover position of the electron beam entering the AT. The operating conditions of the FE gun and the transfer lens have been established so that the aberration effect of the AT lens may be as small as possible for any accelerating voltage (Va) between 400 and 1,000 kV: FE gun voltage (V0) should preferably be larger than 30 kV and the transfer lens should be operated so as to bring the beam crossover to a position near the entrance plane of the AT. These operating conditions can also satisfy the requirement that the electron beam never collides with the AT electrodes. © 1996 Oxford University Press Full-length Papers nationallicence field-emission gun nationallicence high-voltage electron microscope nationallicence accelerating tube nationallicence electrostatic lens nationallicence aberration nationallicence Morita Chiaki Center for Integrated Research in Science and Engineering. Nageya University Furo-cho, Chikusa-ku, Nagoya, 464-01 Japan aut Ohye Toshimi Department of Electrical and Electronic Engineering. Faculty of Science and Technology Meijo University, Shiogamaguchi, Tempaku-ku, Nagoya, 468 Japan aut Shimoyama Hiroshi Department of Electrical and Electronic Engineering. Faculty of Science and Technology Meijo University, Shiogamaguchi, Tempaku-ku, Nagoya, 468 Japan aut Microscopy Oxford University Press 45/5(1996-10), 372-379 0022-0744 45:5<372 1996 45 jmicro https://doi.org/10.1093/oxfordjournals.jmicro.a023454 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1093/oxfordjournals.jmicro.a023454 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Morita Chiaki Center for Integrated Research in Science and Engineering. Nageya University Furo-cho, Chikusa-ku, Nagoya, 464-01 Japan aut NATIONALLICENCE 700 1- Ohye Toshimi Department of Electrical and Electronic Engineering. Faculty of Science and Technology Meijo University, Shiogamaguchi, Tempaku-ku, Nagoya, 468 Japan aut NATIONALLICENCE 700 1- Shimoyama Hiroshi Department of Electrical and Electronic Engineering. Faculty of Science and Technology Meijo University, Shiogamaguchi, Tempaku-ku, Nagoya, 468 Japan aut NATIONALLICENCE 773 0- Microscopy Oxford University Press 45/5(1996-10), 372-379 0022-0744 45:5<372 1996 45 jmicro Metadata rights reserved CC BY-NC-4.0 http://creativecommons.org/licenses/by-nc/4.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-oxford