• Nuclear Engineering and Technology
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• v.41 no.5
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• pp.709-714
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• 2009

An ion implanter, which can serve as a metal-ion supply, has been constructed and performance tested. Copper ions are generated and extracted from a Bernas ion source with a heating crucible that provides feed gases to sustain the plasma. Sable arc plasmas can be sustained in the ion source for a crucible temperature in excess of $350^{\circ}C$. Stable extraction of the ions is possible for arc Currents less than 0.3 A. Arc currents increase with the induced power of a block cathode and the transverse field in the ion source. $Cu^+$ ions in the extracted beam are separated using a dipole magnet. A $20{\mu}A$ $Cu^+$ ion current can be extracted with a 0.2 A arc current. The ion current can support a dose of $10^{16}ions/cm^2$ over an area of $15\;cm^2$ within a few hours.

• Bulletin of the Korean Chemical Society
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• v.27 no.4
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• pp.539-544
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• 2006

Proton transfer reactions and ion-molecule reactions of bifunctional ethanes of $H_2NCH_2CH_2NH_2$, $H_2NCH_2CH_2OH$, and $HOCH_2CH_2OH$ were studied using Fourier transform mass spectrometry (FTMS). The rate constants for proton transfer reactions between the fragment ions and neutral molecules were obtained from the temporal variation of the ion abundances. The rate constants were consistent with the heats of reaction. The fastest proton transfer reactions were the reactions of $CH_2N^+$, $CHO^+$, and $CH_3O^+$ for $H_2NCH_2CH_2NH_2$, $H_2NCH_2CH_2OH$, and $HOCH_2CH_2OH$, respectively. The $[M+13]^+$ ion was formed by the ion-molecule reaction between $H_2C=NH_2 ^+$ or $H_2C=OH^+$ and the neutral molecule. The major product ions generated from the ion-molecule reactions between the protonated molecule and neutral molecule were $[2M+H]^+$, $[M+27]^+$, and $[M+15]^+$.

• Carbon letters
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• v.24
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• pp.55-61
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• 2017

Carbon micropatterns (CMs) were fabricated from a negative-type SU-8 photoresist by proton ion beam lithography and pyrolysis. Well-defined negative-type SU-8 micropatterns were formed by proton ion beam lithography at the optimized fluence of $1{\times}10^{15}ions\;cm^{-2}$ and then pyrolyzed to form CMs. The crosslinked network structures formed by proton irradiation were converted to pseudo-graphitic structures by pyrolysis. The fabricated CMs showed a good electrical conductivity of $1.58{\times}10^2S\;cm^{-1}$ and a very low surface roughness.

• Microbiology and Biotechnology Letters
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• v.38 no.3
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• pp.235-243
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• 2010

For decades, traditional mutation breeding technologies using spontaneous mutation, chemicals, or conventional radiation sources have contributed greatly to the improvement of crops and microorganisms of agricultural and industrial importance. However, new mutagens that can generate more diverse mutation spectra with minimal damage to the original organism are always in need. In this regard, ion beam irradiation, including proton-, helium-, and heavier-charged particle irradiation, is considered to be superior to traditional radiation mutagenesis. In particular, it has been suggested that ion beams predominantly produce strand breaks that often lead to mutations, which is not a situation frequently observed in mutagenesis induced by gamma-ray exposure. In this review, we briefly describe the general principles and history of particle accelerators, and then introduce their successful application in ion beam technology for the improvement of crops and microbes. In particular, a 100-MeV proton beam accelerator currently under construction by the Proton Engineering Frontier Project (PEFP) is discussed. The PEFP accelerator will hopefully prompt the utilization of ion beam technology for strain improvement, as well as for use in nuclear physics, medical science, biology, space technology, radiation technology and basic sciences.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.1104-1108
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• 2004

A Study has been made of surface modification of various polymers by ion implantation to change the optical transmittance property at ultraviolet ray (UV, $200\sim400nm$). The substrates were PC (Polycarbonate), PET(Polyethyleneteraphtalate) and PP (Polypropylene). The effects of ion implantation on the change of optical transmittance were investigated in relation to ion species, implantation energies and ion fluences. The N, Ar, Kr, Xe ion implantation performed at ion energies from 20 to 50keV. The fluences ranged from $5\times10^{15}$ to $7\times10^{16}ions/cm^2$. UV/Vis transmittance spectroscopy, FT-IR and XPS were used to investigate optical transmittance, chemical structure and surface chemical state of irradiated polymer. Surface color was changed from the yellow to the dark brown and the transmittance of UV ray in the range UV-A($320\sim400nm$) decreased more than 80% after ion implantation.

• Journal of the Korean Ceramic Society
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• v.38 no.11
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• pp.993-999
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• 2001

Phase formation and proton conduction in BaO doped LaSc $O_3$with perovskite structure were studied. L $a_{0.6}$B $a_{0.4}$Sc $O_{2.8}$, viz. 40at% $Ba^{2+}$ ion doped composition, showed a single cubic phase, while the other compositions doped less than 30 at% $Ba^{2+}$ ion showed the cubic phase and the orthorhombic one. Above $650^{\circ}C$ oxygen ion conduction was dominant in $N_2$atmosphere and below this temperature proton conduction was observed in wet atmosphere. All compositions were found to be the pure proton conductors below 30$0^{\circ}C$. The proton conductivity (bulk) of L $a_{0.6}$B $a_{0.4}$Sc $O_{2.8}$ was higher than those of any other composition.osition.ion.

• Bulletin of the Korean Chemical Society
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• v.25 no.10
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• pp.1538-1544
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• 2004

Fragmentations and proton transfer reactions of mono-, di-, and triethanolamines were studied using FTMS. It was found that the most abundant fragment ion was $[M-CH_2OH]^+$. The $[M-CH_2OH-H_2O]^+$ was observed in the mass spectra of diethanolamine and triethanolamine. By increasing the ion trapping time in the ICR cell, the $[M+H]^+$ and $[M+H-H_2O]^+$ ions were notably increased for all the samples while the $[M+H-2H_2O]^+$ was observed in the mass spectra of diethanolamine and triethanolamine. The proton transfer reactions between the fragment ions and neutral molecules occurred predominantly by increasing the ion trapping time. The rate constants for the proton transfer reactions were calculated from experimental results. The proton transfer reaction of $CHO^+$ was the fastest one, which is consistent with the heats of reaction. The rate constants for proton transfer reactions of triethanolamine were much slower than those of ethanolamine and diethanolamine because of the steric hindered structure of triethanolamine. The plausible structures of observed ions and heats of reaction for proton transfer were calculated with AM1 semiempirical method.

• Journal of Korean Vacuum Science & Technology
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• v.6 no.1
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• pp.30-35
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• 2002

We show that a combined technique of Cs$^{+}$ reactive ion scattering (Cs$^{+}$ RIS) and low-energy secondary ion mass spectrometry (LESIMS) provides a powerful means for probing molecular films and their surface reactions. Simple molecules, including HCI, NH$_3$, D$_2$O, and their mixtures, were deposited into a thin film of several monolayer thickness on Ru(001) at low temperature in vacuum, and the surface was characterized by Cs$^{+}$ RIS and LESIMS. On pure films, D$_2$O, HCI, and NH$_3$ existed in the corresponding molecular states. When HCI and NH$_3$ were co-deposited, ammonium ion(NH$_4$$^{+}$) was readily formed by proton transfer from HCI to NH$_3$. In the presence of water molecules, HCI ionized first to hydronium ion(H$_3$O$^{+}$), which subsequently transferred proton to NH$_3$ to form NH$_4$$^{+}$. The proton transfer, however, did not occur to a completion on ice, in contrast to the complete reaction in aqueous solutions.s solutions.

• Bulletin of the Korean Space Science Society
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• 2003.10a
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• pp.37-37
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• 2003

Electron whistlers frequently excite proton whistlers. The proton whistlers appear on the dynamic spectrum as rising tones, which start after the reception of a short electron whistler, asymptotically approaching the local proton gyro-frequency. The proton whistlers are dispersed forms of lightning impulses and their dispersion can be explained by the effects of heavy ions such as H+ and He+ on the propagation of an electromagnetic wave in the ionosphere. In the ionosphere, a right-handed circularly-polarized electron whistler becomes coupled to a left-handed circularly-polarized proton whistler when the frequency becomes close to a cross-over frequency. By adopting the multi-fluid numerical wave model, we examine how the mode coupling varies as the ion composition changes along altitude in the mid-latitude ionosphere. The time histories and dynamic spectra of electric fields are presented. In addition, we compare our results with the previous theoretical and observational studies.

• Proceedings of the Korean Nuclear Society Conference
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• 2005.10a
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• pp.919-920
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• 2005