• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.379-381
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• 2002

Mitsubishi Electric Corporation has marketed a series of multimedia CRTs enabling bright picture windows in a high-resolution date display screen. The key components of the multimedia CRTs named Diamondtran $M^2$ are a high-gm (low drive-voltage) electron gun and an aperture grille mask. A high-gm electron gun has been developed by designing a beam forming region with high-gm configuration combining with a high current-density cathode. The development of next generation high-gm guns are also introduced

• Bulletin of the Korean Chemical Society
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• v.12 no.3
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• pp.241-243
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• 1991

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.6
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• pp.153-158
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• 2007

The present study covers numerical analysis of a thermionic scanning electron microscope(SEM) column. The SEM column contains an electron optical system in which electrons are emitted and moved to form a focused beam, and this generates secondary electrons from the specimen surfaces, eventually making an image. The electron optical system mainly consists of a thermionic electron gun as the beam source, the lens system, the electron control unit, and the vacuum unit. For a systematic design of the electron optical system, the beam trajectories are investigated through numerical analyses by tracing the ray path of the electron beams, and the quality of resulting image is evaluated from the analysis results.

• Proceedings of the Korean Vacuum Society Conference
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• 1997.07a
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• pp.95-95
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• 1997

• Vacuum Magazine
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• v.4 no.1
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• pp.12-15
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• 2017

The Pohang Accelerator Laboratory X-ray Free Electron Laser (PAL-XFEL) is a 0.1 nm hard X-ray FEL which aims at providing photon flux higher than $1{\times}10^{12}$ photons/pulse using a 10-GeV electron linac. The vacuum system of the machine consists of an injector section including an S-band photocathode RF gun, 10-GeV electron linac section based on S-band normal conducting accelerating structures and a 150-m long out-vacuum undulator system. We introduce the present status of PAL-XFEL vacuum systems.

• Journal of the Korean Ceramic Society
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• v.37 no.1
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• pp.6-11
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• 2000

Electron emission from the Pb(ZrxTi1-x)O3 ferroelectrics by pulsed electric field has been investigated as a function of Zr/Ti ratios such as 35/65, 50/50 and 65/35 below 250kV/cm. Electrons were emitted regardless of the applied field polarity to the rear electrode. When the negative field was applied to the rear electrode, the electron emission charge was more stable. It was proved that the electrons were emitted at the edge of the upper electrode. The emission charge increased in order of 65/35>50/50>35/65. The electron emission characteristics were dependent on the ferroelectric properties such as polarization and coercive field. The emission charge and emission threshold field were affected by the polarization change and the coercive field, respectively. This result explains that the electron emission is a field emission with polarization induced surface potential by a modified Fowler-Nordheim plot of emission charge.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.5
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• pp.52-57
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• 2008

Most of the electrons emitted from the filament, are captured by the anode. The portion of the electron current that leaves the gun through the hole in the anode is called the beam current. Electron beam probe is called the focused beam on the specimen. Because of the lenes and aperture, the probe current becomes smaller than the beam current. It generate various signals(backscattered electron, secondary electron) in an interaction with the specimen atoms. Backscattered electron provide an useful signal for composition and local specimen surface inclination. Secondary electron is used far the formation of surface imagination. The steady electron beam probe is very important for the imagination formation and the brightness. In this paper, we show the results of developed elements that create electron beam probe and the measured beam probe in various acceleration voltages by Faraday cup. These data are used to analysis and improve the performance of the system in the development.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.401-404
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• 2004

The electron beam machining provides very high resolution up to nanometer scale, hence the E-beam writing technology is rapidly growing in MEMS and nano-engineering areas. In the optical column of the e-beam writer, there are several lenses condensing and focusing electron beams from electron gun with fringing magnetic fields. To achieve small spot size as 1-2 nm for higher power of electron beam, magnetic lenses should be designed considering their magnetic field distribution. In this paper, the magnetic field at two condenser lenses and object lens are calculated with finite element method and discussed its performances.

• Applied Microscopy
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• v.36 no.spc1
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• pp.63-69
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• 2006

By utilizing a field emission gun and a biprism installed on a transmission electron microscope (TEM), electron holography is extensively carried out to visualize the electric and magnetic fields of nanomaterials. In the electric field analysis, the distribution of electric potential in a sharp tip made of W coated with $ZrO_2$ is visualized by applying the voltage to the tip. Denser contour lines due to the electric potential are observed with an increase in the bias voltage. In the magnetic field analysis by producing the strong magnetic field with a sharp magnetic needle made of a permanent magnet, the in situ experiment is carried out to investigate the magnetization of hard magnetic materials. The results of these experiments clearly demonstrate that electron holography is a promising advanced transmission electron microscopy technique to characterize the electric and magnetic properties of nanomaterials.

• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1391-1393
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• 1995

An electron gun system for the Pohang Light Source has been installed and operated successfully. The basic design parameters are acceleration voltage of 80 kV, maximum peak emission current of 5 A, minimum pulse width of 1 ns, and maximum repetition rate of 100 Hz. The gun has a triode structure and is composed of a cathode, a focusing electrode(Wehnelt), and an anode. To sustain a $5{\times}10^{-9}$Torr vacuum, a $230{\ell}/s$ Ion pump has been adopted. We adopted a control and monitoring system based on the fiber-optic technology. In this article, we present the structure and operation principle of the system with special interest on the nanosecond pulser, remote control and monitoring system.