• 마이크로전자및패키징학회지
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• 제30권3호
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• pp.56-63
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• 2023

본 연구에서는 졸-겔 IGZO(Indium-Gallium-Zinc Oxide) 박막을 만들고 이에 전자빔을 조사 한 후 박막 트랜지스터로 제작하여 전자빔 조사가 박막 트랜지스터의 전기적 특성에 미치는 영향을 비교 분석하였다. 특히 전자빔이 조사되는 환경을 대기 중과 질소 분위기(<200 ppm O₂)로 두고 전자빔 조사 선량 세기를 100kGy와 200kGy로 각각 조사한 후 350℃ 온도에서의 열처리만 진행한 비교군과 비교 분석을 진행하였다. 전자빔 조사에 따른 졸-겔 IGZO 박막의 물성 변화를 분석하기 위해 UV-Visible spectroscopy, X-ray diffraction(XRD)와 X-ray photoelectron spectroscopy(XPS)를 분석 결과, 전자빔 조사 전·후의 모든 조건 하에서 가시광 영역에서의 80% 이상의 높은 투과도를 보여줌을 확인할 수 있었고, XRD 분석 결과를 통해 전자빔 조사와 관계없이 비정질 특성을 유지함을 확인하였다. 특히 전자빔 조사에 따라 졸-겔 IGZO 박막에 화학적 조성 변화가 있음을 확인하였는데, 질소 분위기에서 전자빔을 조사하게 되면 M-O결합과 관련된 peak이 차지하는 비율이 높아짐을 확인할 수 있었다. 질소 분위기에서 전자빔이 조사된 TFT들은 on/off 비율, 전자 이동도에서 향상된 특성을 보여주었으며, 시간에 따라 트랜지스터의 특성들(on/off 비율, 문턱전압, 전자이동도, 하위임계값 스윙)의 수치 또한 큰 변화 없이 유지됨이 확인되어, 졸-겔 공정 TFT 제작에 있어서 질소 분위기에서의 전자빔 조사공정이 IGZO기반 박막 트랜지스터의 전기적특성의 개선에 기여할 수 있을 것으로 기대된다.

• 한국의학물리학회지:의학물리
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• 제22권2호
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• pp.85-91
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• 2011

GEANT4 Medical Linac 2 예제 코드를 이용하여 선형가속기 전자선의 에너지 분포를 계산하였다. 입사 전자의 평균 에너지는 6, 9, 12, 16, 20 MeV이었으며, 전자선 특성에 영향을 주는 전자선 산란박 물질, 두께, 위치에 따른 에너지 분포를 계산하였다. 산란박 물질은 납, 구리, 알루미늄, 금을 사용하였다. 산란박 위치를 변경하여 선형 가속기 헤드 속 산란박 위치가 전자 및 광자 에너지 분포에 미치는 영향을 분석하였다. 의료용 선형가속기 시뮬레이션의 기초자료인 에너지 분포에 대해 여러 가지 산란박 조건을 적용하여 경향을 나타내었다. 이 결과는 선형가속기 헤드 설계에 이용될 수 있을 것으로 본다.

• 한국의학물리학회지:의학물리
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• 제31권4호
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• pp.163-171
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• 2020

Purpose: In this study, the accuracies of electron Monte Carlo (eMC) calculation algorithms were evaluated to determine whether electron beams were modeled by optional air profiles (APs) designed for each applicator size. Methods: Electron beams with the energies of 6, 9, 12, and 16 MeV for VitalBeam (Varian Medical System, Palo Alto, CA, USA) and 6, 9, 12, 16, and 20 MeV for Clinac iX (Varian Medical System) were used. Optional APs were measured at the source-to-detector distance of 95 cm with jaw openings appropriate for each machine, electron beam energy, and applicator size. The measured optional APs were postprocessed and converted into the w2CAD format. Then, the electron beams were modeled and calculated with and without optional APs. Measured profiles, percentage depth doses, penumbras with respect to each machine, and energy were compared to calculated dose distributions. Results: For VitalBeam, the profile differences between the measurement and calculation were reduced by 0.35%, 0.15%, 0.14%, and 0.38% at 6, 9, 12, and 16 MeV, respectively, when the beams were modeled with APs. For Clinac iX, the differences were decreased by 0.16%, -0.31%, 0.94%, 0.42%, and 0.74%, at 6, 9, 12, 16, and 20 MeV, respectively, with the insertion of APs. Of note, no significant improvements in penumbra and percentage depth dose were observed, although the beam models were configured with APs. Conclusions: The accuracy of the eMC calculation can be improved in profiles when electron beams are modeled with optional APs.

• 한국방사선학회논문지
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• 제15권1호
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• pp.79-83
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• 2021

방사선 치료 영역에서 전자선은 표재성 병변 치료에 자주 쓰인다. 전자선은 빔 경로에 것들과 상호 작용하여 선량측정에 영향을 끼치기에 정확한 측정이 요구된다. 하지만 전자선 정도관리에 관한 연구는 이루어지고 있지 않는 실정이다. 이에 본 연구에서는 전자선 정도관리를 위한 기초연구로 PbO 기반의 선량계를 제작하였다. 그리고 6, 9, 12 MeV 에너지에 따른 재현성, 선형성을 분석하여 계측정확성과 정밀성을 평가하였다. 재현성 측정결과 6, 9, 12 MeV에서 각각 1.024%, 1.019%, 0.890%의 RSD 값으로 나타났다. 그리고 선형선 측정결과에서는 6, 9, 12 MeV에서 모두 0.9999 R2로 나타났다. 두 평가 모두 우수한 결과로 PbO 선량계의 계측정확성과 정밀성이 매우 우수한 것으로 나타났다.

• 한국축산식품학회지
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• 제34권5호
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• pp.570-575
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• 2014

This study was conducted to compare the effects of two forms of radiation (electron and X-ray; generated by an electron beam accelerator) on the conformation and antigenic properties of hen's egg albumin, ovalbumin (OVA), which was used as a model protein. OVA solutions (2.0 mg/mL) were individually irradiated by electron beam or X-ray at the absorbed doses of 0 (control), 2, 4, 6, 8, and 10 kGy. No differences between the two forms of radiation on the structural properties of OVA were shown by spectrometric and electrophoretic analyses. The turbidity of OVA solution increased and the main OVA bands on polyacrylamide gels disappeared after irradiation, regardless of the radiation source. In competitive indirect enzyme-linked immunosorbent assay, OVA samples irradiated by electron beam or X-ray showed different immunological responses in reactions with monoclonal and polyclonal antibodies (immunoglobulin G) produced against non-irradiated OVA. The results indicate that electron beam irradiation and X-ray irradiation produced different patterns of structural changes to the OVA molecule.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.187-187
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• 2012

In this report, the plasmonic nanopores of less than 5 nm diameter were fabricated on the apex of the pyramidal cavity array. The metallic pyramidal pit cavity can also utilized as the plasmonic bioreactor, and the fabricated Au or Al metallic nanopore can provide the controllable translocation speed down using the plasmonic optical force. Initially, the SiO2 nanopore on the pyramidal pit cavity were fabricated using conventional microfabrication techniques. Then, the metallic thin film was sputter-deposited, followed by surface modification of the nanometer thick membrane using FESEM, TEM and EPMA. The huge electron intensity of FESEM with ~microsecond scan speed can provide the rapid solid phase surface transformation. However, the moderate electron beam intensity from the normal TEM without high speed scanning can only provide the liquid phase surface modification. After metal deposition, the 100 nm diameter aperture using FIB beam drilling was obtained in order to obtain the uniform nano-aperture. Then, the nanometer size aperture was reduced down to ~50 nm using electron beam surface modification using high speed scanning FESEM. The followed EPMA electron beam exposure without high speed scanning presents the reduction of the nanosize aperture down to 10 nm. During these processes, the widening or the shrinking of the nanometer pore was observed depending upon the electron beam intensity. Finally, using 200 keV TEM, the diameter of the nanopore was successively down from 10 nm down to 1.5 nm.

• Preventive Nutrition and Food Science
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• 제11권1호
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• pp.73-77
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• 2006

Ground pork was irradiated with an electron beam (e-beam) at a dose of 0, 1.5, 3, 5 and 10 kGy and the changes in various functional and other associated properties of salt-soluble proteins extracted from the pork were evaluated. Irradiation did not affect turbidity and the disulfide content of pork salt-soluble protein, but the content of sulfhydryls and the hydrophobocity of salt-soluble protein increased. This indicates that protein degradation occurred when the pork was e-beam irradiated and that the sulfhydryls and hydrophobic moieties buried inside the proteins were exposed to the outside environment. However, these degraded protein molecules did not form large protein aggregates through disulfide bridges. The emulsifying capacity of the pork increased with irradiation, which could be the result from increased hydrophobicity of pork salt-soluble protein. Water holding capacity of pork was not affected bye-beam irradiation.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.802-805
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• 2003

The ion-induced secondary electron emission coefficient ${\gamma}$ for MgO thin film with $O_{2}$ plasma treatment has been investigated by ${\gamma}$-FIB (focused ion beam) system. The MgO thin film deposited from sintered material with $O_2$ plasma treatment is found to have higher ${\gamma}$ than that without $O_{2}$ plasma treatment. The energy of $Ne^{+}$ ions used has been ranged from 100eV to 200eV throughout this experiment. It is found that the highest secondary electron emission coefficient ${\gamma}$ has been achieved for 10 minutes of $O_{2}$ plasma treatment.

• 대한기계학회논문집
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• 제19권2호
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• pp.427-432
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• 1995

Surface heat treatment using a laser beam or an electron beam is studied through numerical analyses and experiments. For the surface heat treatment process, a theoretical model is developed to predict the effects of laser beam power, travel speed and properties of a workpiece on the depth and width of the heat affected zone(HAZ). The shape of HAZ and the hardness of heat-treated surface are experimentally obtained using an electron beam. Three materials(SS41, S45C and S55C) are selected as workpiece materials. The hardness of HAZ is increased up to 3 times for materials of a low carbon content. The results of the numerical analysis are compared with those of experiments. The comparison shows that the numerical model predicts larger depths and widths.

• 펄프종이기술
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• 제46권4호
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• pp.37-43
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• 2014

The crystallinity and molecular weight of cotton linter need to be controlled to be more easily dissolved in NMMO during manufacture of clothing fabrics. Electron beam irradiation and sulfuric acid treatment were used as pre-treatment to reduce molecular weight of cotton linter more efficiently, and after the pre-treatment, peroxide bleaching was followed in alkaline condition. After those processes, the crystalline indices of the cotton linters were measured by XRD method, and other properties such as their alpha cellulose contents and degree of polymerization were measured. It was found that the crystallinity index of cotton linter was decreased as the irradiation of electron beam increased while increased as the dose of sulfuric acid increased. These results strongly suggested that electron beam damaged the crystalline structure of the cellulose directly while sulfuric acid dissolved mostly non-crystalline area of the cellulose structure.