• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2004년도 학술대회지
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• pp.301-305
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• 2004

Effects of ion implantation on the adhesion strength of DLC film as a function of ion doses and implanted energies were investigated. Ti ions were implanted on the Si-wafer substrates followed by DLC coating using ion beam deposition method. Adhesion strength of DLC films were determined by scratch adhesion tester. Morphologies and compositional variations at the different ion energies and doses were observer by Laser Microscope and Auger Electron Spectroscopy, respectively. From results of scratch test, the adhesion strength of films was improved as increasing ion implanted energy, however there was no significant evidence with ion dose.

• Journal of Astronomy and Space Sciences
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• 제11권2호
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• pp.250-272
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• 1994

Various plasma instabilities driven by the ion beams have been proposed in order to explain the broadband electrostatic noise (BEN) in the earth's geomagnetic tail. Ion acoustic, ion-ion two stream, and electron acoustic instabilities have been proposed. Here we consider a theoretical investigation of the generation of BEN by cold streaming ion beams in the earth's magnetotail. Linear theory analysis and particle simulation studies for the plasma sheet, which consists of warm electrons and ions as well as cold streaming ion beams, have been done. Both beam-ion acoustic and ion-ion two stream instabilities easily occur when the beam and warm electron temperature ratio, $T_b/T_e$ is small enough. The numerical simulation results confirm the existence of broadband electrostatic noise whose frequency is ranged from $\omega$=0 to $\omega$$\omega_{pe}$.

• 한국환경과학회지
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• 제11권9호
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• pp.993-999
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• 2002

Waste paper cup was sulfonated to be used as ion exchanger. Removal characteristic of copper and lead ion by prepared ion exchanger was investigated. The sulfonation was conformed by the high intensity band of $SO_3H$ group around 1100~$1160cm^{-1}$. The synthesized ion exchanger had greater removal ability for copper and lead ion than the original waste paper cup. Ion exchange system reached the final equilibrium plateau within 30min. The maximum removal capacities $q_{max}$ were calculated as 9.79mg/g fur copper and 15.95mg/g for lead, respectively. The affinity of lead based on a weight was higher than that of copper. The ion exchange phenomena appeared to follow a typical Freundlich isotherm.

• Nuclear Engineering and Technology
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• 제35권3호
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• pp.226-233
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• 2003

The discharge characteristics of a prototype ion source was investigated, which was developed and upgraded for the NBI (Neutral Beam Injection) heating system of KSTAR (Korea Superconducting Tokamak Advanced Research). The ion source was designed for the arc discharge of magnetic bucket chamber with multi-pole cusp fields. The ion source was discharged by the emission-limited mode with the control of filament heating voltage. The maximum ion density was 4 times larger than the previous discharge controlled by a space-charge-limited mode with fully heated filament. The plasma (ion) density and arc current were proportional to the filament voltage, but the discharge efficiency was inversely proportional to the operating pressure of hydrogen gas. The maximum ion density and arc current were obtained with constant arc voltage ($80{\sim}100V$), as $8{\times}10^{11}cm^{-3}$ and 1200 A, respectively. The estimated maximum beam current was about 35 A, extracted by the accelerating voltage of 80kV.

• Applied Science and Convergence Technology
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• 제25권6호
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• pp.116-119
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• 2016

In this study, we fabricated the $K^+$ ion source for the various purposes and investigated the emission characteristics. The fabricated $K^+$ ion source was painted in the tungsten filament to make filament type ion source. The RGA spectra show that the filament type $K^+$ ion source has a good out gassing character, so it can be used in the ultra-high vacuum system. The maximum $K^+$ ion current was 20 mA when filament temperature was 1410 K and filament potential was 50 V. When the filament temperature was 1070 K, the initial beam current was 50 mA and decreased only by 2% during 4 hours. The emitting energy was measured to be 2.04 eV. This low value means that the fabricated specimen is a good $K^+$ ion source. We conclude that this filament type ion source can be used in various fields, including the LEIS research.

• 한국전기전자재료학회논문지
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• 제16권3호
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• pp.175-180
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• 2003

As the integrated circuit device shrinks to the deep submicron regime, the ion implantation process with high ion dose has been attracted beyond the conventional ion implantation technology. In particular, for the case of boron ion implantation with low energy and high dose, the stabilization and throughput of semiconductor chip manufacturing are decreasing because of trouble due to the machine conditions and beam turning of ion implanter system. In this paper, we focused to the improved characteristics of processing conditions of ion implantation equipment through the modified deceleration mode. Thus, our modified recipe with low energy and high ion dose can be directly apply in the semiconductor manufacturing process without any degradation of stability and throughput.

• 한국군사과학기술학회지
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• 제14권6호
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• pp.1107-1113
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• 2011

In this paper, ion beam technology was investigated through the published papers. Ion beam technology is mainly used by the focused ion beams. There are two different types of application methods. One method is to remove the material from the substrate, the other one is to deposit the materials on the surface of the substrate or specimen. Based on the literature review there are 1.5 times more published research papers related to the deposition than those of the removal.

• 통합자연과학논문집
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• 제5권3호
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• pp.175-181
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• 2012

Oxepane high explosives substituted to explosive group such as azido, nitrato and hydrazino are investigated theoretically the acid catalyzed reaction using the semiempirical MINDO/3, MNDO and AM1 methods to use as the guidelines of high explosives. The nucleophilicity and basicity of oxepane high explosives can be explained by the value of negative charge on oxygen atom of oxepane and the reactivity in propagation step can be represented by the value of positive charge on carbon atom and low electrophile LUMO energy. It was known that carbenium ion was favorable due to the stable energy (19.507~32.101 Kcal/mol) between oxonium ion and carbenium ion in the process of cyclic oxonium ion of oxepane high explosives being converted to open carbenium ion in oxepane high explosives. The value of concentration of cyclic oxonium ion and open carbenium ion in equilibrium status was found to be a major determinant of mechanism, it was expected to react faster in the prepolymer propagation step in SN1 mechanism than in that of $S_N2$.

• Korean Chemical Engineering Research
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• 제59권2호
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• pp.219-224
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• 2021

Ion flotation is an efficient method to remove metal ions from aqueous solution. In this work, ion flotation was applied to calcium removal from aqueous solution. The parameters used included sodium stearate (SS) and sodium dodecyl sulfate (SDS) as collectors, 1-butanol and 1-propanol as frothers, pH, and air-flow rate. An L16 orthogonal array was chosen according to the mentioned factors and levels, and experimental tests were conducted according to the Taguchi orthogonal array. The results showed that all of the factors except one had significant effect on the flotation performance. The percentage contribution of parameters showed that type of frother and type of collector made the greatest (43.14%) and the lowest (9.86%) contribution, respectively. In optimal conditions, the recovery of Ca (II) ion was 45.67%. Also, the results illustrated that the Taguchi method could predict calcium removal from aqueous solution by ion flotation with 2.63%. This study showed that the use of ion flotation was an effective method for Ca (II) ion removal from aqueous solution.

• 한국표면공학회지
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• 제37권4호
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• pp.220-225
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• 2004

A new ion beam extraction system is designed using a simple ion mass filter and a micro mass balance and a QMS based detecting system. A quadrupole Mass Filter is used for selective ion beam formation from inductively coupled high density plasma sources with appropriate electrostatic lens and final analyzing QMS. Also a quartz crystal microbalance is set between a QMF and a QMS to measure the etching and polymerization rate of the mass selected ion beam. An inductively coupled plasma was used as a ion/radical source which had an electron temperature of 4-8 eV and electron density of $4${\times}$10^{11}$＃/㎤. A computer interfaced system through 12bit AD-DA board can control the pass ion mass of the qmf by setting RF/DC voltage ratio applied to the quadrupoles so that time modulation of pass ion's mass is possible. So the direct measurements of ion - surface chemistry can be possible in a resolution of $1\AA$/sec based on the qcm's sensitivity. A full set of driving software and hardware setting is successfully carried out to get fundamental plasma information of the ICP source and analysed $Ar^{+}$ beam was detected at the $2^{nd}$ QMS.