Tsunenari Saito

Tohoku University

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Trends

Author Order

Document Type

Co-Authors

O. J. Sovers

Jet Propulsion Laboratory

Yuko Matsumoto

National Center For Child Health and Development

Takashi Kawano

Keihin (Japan)

Yoshizo Takai

Osaka University

Kazuyuki Ueno

Iwate University

Ryuichi Shimizu

International Institute for Advanced Studies

Shigeo Kubota

Kawasaki Hospital

Seisuke Yamanaka

Digital Video (Italy)

Byung Mook Weon

Sungkyunkwan University

Gong Seog Park

Cooperative Institutions

Osaka University

Graduate School USA

Sony (Taiwan)

Osaka Institute of Technology

International Institute for Advanced Studies

Sony Corporation (United States)

Sony Computer Science Laboratories

Materials Science & Engineering

Pohang University of Science and Technology

Imaging Center

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Field

Numerical calculations of focal and aberration properties of unipotential electron lenses

Journal of Applied Physics (1977)

Tsunenari Saito O. J. Sovers

Focal properties and aberration coefficients of equidiameter unipotential electron lenses are calculated by numerical solution of Laplace’s equation and the electron trajectory equations. A wide range of central electrode length-to-diameter ratios is investigated. The variation of focal and aberration properties with lens geometry is well described by relatively simple analytic functions, which are found to be useful in practical lens design problems. Agreement with experimentally measured focal properties is excellent.

Electrostatic lens

Electron optics

Contrast transfer function

10.1063/1.323989

Cite

Citations (14)

Design of complex electron lenses consisting of two double cylinders

Journal of Applied Physics (1979)

Tsunenari Saito Masahiro Kikuchi O. J. Sovers

A family of complex electron lenses, consisting of two coaxial double-cylinder elements with unequal diameters, is investigated. It is concluded that the dominant contribution to the spherical aberration of such lenses arises in the accelerating component. Considerable reduction of the shperical aberration coefficient is possible in comparison with the unipotential and bipotential lenses customarily employed in cathode-ray-tube electron-optical systems.

Electron optics

Electrostatic lens

Coaxial

Geometrical optics

10.1063/1.325784

Cite

Citations (8)

A New Trinitron Color TV With Beam-Scan Velocity Modulation

IEEE Transactions on Consumer Electronics (1976)

Y. Fuse Seisuke Yamanaka Tsunenari Saito

The greater part of the beam current in current color CRTs is blocked by the aperture masks. Consequently relatively high electron beam currents are required to obtain sufficient brightness, and this usually leads to increased beam spot size on the phosphor screen and to inferior spatial frequency reproduction characteristics. In order to remedy this drawback, the usual practice has been to boost the amplitude of the luminance signal in the high-frequency region. Typical of such methods is the so-called "aperture-compensation method".

CRTS

Aperture (computer memory)

SIGNAL (programming language)

Modulation (music)

10.1109/tce.1976.266759

Cite

Citations (3)

Digital computer studies of electron lenses for cathode-ray tubes

Journal of Applied Physics (1973)

Tsunenari Saito Shigeo Kubota Senri Miyaoka

The focal properties and the third-order aberration coefficients of a number of unipotential lenses and a bipotential lens were investigated numerically using digital methods. The differential quotients of aberration coefficients in terms of the entrance pupil position were obtained in excellent agreement with those given by Berek in glass optics. The aberration coefficients were also calculated under the Fraunhofer condition for an infinite image position. For a fixed focal length, spherical aberration coefficients decrease and astigmatism coefficients increase as the length of the center electrode increases for equidiameter unipotential lenses. The symmetrical bipotential lens is almost astigmatism free for various voltage ratios; however, its spherical aberration coefficient is two to five times larger than those of equidiameter unipotential lenses operated at the same focal length.

Chromatic aberration

Electrostatic lens

Astigmatism

Optical aberration

Contrast transfer function

Electron optics

Position (finance)

10.1063/1.1661990

Cite

Citations (11)

Evolution of a dipole in two-dimensional flows

Bulletin of the American Physical Society (2007)

Yuko Matsumoto Tsunenari Saito Kazuyuki Ueno

Source

Cite

Citations (0)

Oxide cathodes for reliable electron sources

Journal of Information Display (2005)

Byung Mook Weon Jung Ho Je Gong Seog Park Nam Je Koh David S. Barratt

Abstract In this paper, we investigate the oxide cathodes for the development of reliable electron sources. Poisoning in oxide cathodes is one of the serious problems in achieving reliable electron emission. In particular, early poisoning induces poor life performance as will be demonstrated herein. The survivability of electron emission sources is significantly improved by high doping of high‐speed activator. The robust oxide cathodes with 0.17 % Mg operating at about 1,050 K are expected to work for very long times (>100,000 hours). We suggest that this key idea will contribute to solving the basic problems in oxide cathodes such as poisoning or ion bombardment for high power or high frequency applications of electron sources.

10.1080/15980316.2005.9651988

Cite

Citations (3)

Spherical aberration coefficients of double-cylinder electrostatic lenses over wide magnification ranges

Journal of Applied Physics (1979)

Tsunenari Saito O. J. Sovers

Focal properties and spherical aberration coefficients of double-cylinder bipotential electron lenses are calculated by numerical solution of Laplace’s equation and the electron trajectory equations. A wide range of electrode gap sizes is investigated. The variation of focal and aberration properties with lens geometry, magnification, and focus voltages is represented by analytic functions. These describe the entire family of lenses to a high degree of approximation, and are expected to be useful in practical lens design problems. At a fixed focal length, it is possible to decrease the spherical aberration coefficient substantially by increasing the electrode gap size.

Electrostatic lens

Contrast transfer function

Electron optics

10.1063/1.326381

Cite

Citations (7)

Unique source for scandium oxide layer deposition on tungsten for surface study of high electron emissivity

Surface and Interface Analysis (1999)

Takashi Kawano Tsunenari Saito Yoshizo Takai Ryuichi Shimizu

The objective was to prepare scandium oxide layers on tungsten for the surface study of Sc-O/W(100) emitters using two design types of a compact evaporator for Sc2O3 and for metallic scandium deposition. Both of these evaporators were compatible with ultrahigh vacuum operation in a specimen chamber optimized for surface analytical measurements. The Sc2O3 evaporator allowed Sc2O3 to be deposited on a substrate while maintaining its stoichiometric composition. It was also demonstrated that scandium oxide layers could be prepared effectively on a substrate by deposition of metallic scandium followed by oxygen exposure. Copyright © 1999 John Wiley & Sons, Ltd.

Scandium

Deposition

10.1002/(sici)1096-9918(199911)27:11<981::aid-sia662>3.0.co;2-1

Cite

Citations (8)

Unique source for scandium oxide layer deposition on tungsten for surface study of high electron emissivity

Surface and Interface Analysis (1999)

Takashi Kawano Tsunenari Saito Yoshizo Takai Ryuichi Shimizu

Scandium

Deposition

Tungsten Oxide

10.1002/(sici)1096-9918(199911)27:11<981::aid-sia662>3.3.co;2-t

Cite

Citations (0)

A moment model with variable length scale for the motion of a vortex pair in two-dimensional incompressible flows

Physics of Fluids (2009)

Yuko Matsumoto Kazuyuki Ueno Tsunenari Saito

A simple model for the motion of a vortex pair in two-dimensional inviscid flows is presented. In this model the motion of the vortex pair is expressed by a set of ordinary differential equations for the dipole moment, the length scale, and the centroid position. The length scale is the distance between the positive vortex and the negative vortex in the pair. A self-propelling velocity of the model vortex pair is introduced in response to a wide range of the length scale. If a background flow is a linear function of the position, the dipole moment and the length scale of the model are exact. This model works well for a separated vortex pair, although it is not applicable to an asymmetrically deformed vortex pair.

Inviscid flow

Burgers vortex

Length scale

Vortex stretching

Position (finance)

Starting vortex

10.1063/1.3118648

Cite

Citations (8)