• 방사선산업학회지
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• 제4권4호
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• pp.359-364
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• 2010

PVDF-HFP (binder)/silylated alumina (inorganic particle)-coated PE (polyethylene) separators were with various compositions of binder and inorganic particle were prepared by a dip-coating process with humidity control (R.H. 25% and 50%) using electron beam irradiation. The morphology of the coated PVDF-$HFP/Al_2O_3$ layer with various compositions of PVDF-HFP and $Al_2O_3$, and humidity condition was found to be an important factor in determining ionic conductivity of the prepared separators. The PVDF-$HFP/Al_2O_3$ (5/5)-coated PE separator prepared at R.H. 50% followed by electron beam irradiation at 200 kGy was applied for lithium-ion polymer battery and the cell test results showed improved high-rate discharge performance and better cyclic stability compared to the cells with the bare PE and the PVDF-HFP-coated PE separators.

• 한국산업융합학회 논문집
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• 제21권6호
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• pp.337-344
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• 2018

Food irradiation is important not only in ensuring safety but also improving antioxidant activity of peaches. Our objective was to establish the best irradiation treatment for peaches by calculating dose distribution using Monte Carlo simulation. 3-D geometry and component densities of peaches, extracted from CT scan, were entered into MCNP to obtain simulated dose distribution. Radiation energies for electron beam were 1.35 MeV (low energy) and 10 MeV (high energy). Co (1.25 MeV) and the Husman irradiator, containing three sealed Cs source rods in an annular array, were used for gamma irradiation. At 1.35 MeV electron beam simulation, electrons penetrated well beyond the peach skin, enough for surface treatment for microorganisms and allergens. At 10 MeV electron beam simulation, for top-beam only treatment, doses at the core were the highest and for double beam treatment, the electron energy was absorbed by the entire sample. At Co source, the radiation doses were presented on the whole area. At Cs source, the dose uniformity ratios were 2.78 for one source and 1.48 for three ones at 120 degrees interval. Proper control of irradiation treatment is critical to establish confidence in the irradiation process.

• Applied Microscopy
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• 제45권4호
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• pp.218-224
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• 2015

A technical overview on the various sample preparation methods for electron backscattered diffraction (EBSD) analysis is carried out. The mechanical polishing with colloidal silica finish, electro-chemical polishing, dual layer coating and ion beam milling are introduced for the common sample preparation methods for EBSD observation and some issues that are frequently neglected by the common EBSD users but should be considered to get a reliable EBSD data are discussed. This overview would be especially helpful to the people who know what EBSD technique is but do not get a reliable EBSD data because of difficulties in sample preparation.

• 대한방사선기술학회지:방사선기술과학
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• 제23권1호
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• pp.97-101
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• 2000

In this study, the highly sensitive $CaSO_4:Tm$-PTFE TLDs has been fabricated for the purpose of measurement of high energy electron. $CaSO_4:Tm$ phosphor powder was mixed with polytetrafluoroethylene(PTFE) powder and moulded in a disk type(diameter 8.5 mm. thickness $90\;mg/cm^2$) by cold pressing. The absorbed dose distribution and ranges for high energy electron were measured by using the $CaSO_4:Tm$-PTFE TLDs. The ranges determined were $R_{100}=14.5mm$, $R_{50}=24.1mm$ and $R_P=31.8mm$, respectively and the beam flatness, the variation of relative dose in 80% of the field size, was 4.5%. The fabricated $CaSO_4:Tm$-PTFE TLDs nay be utilized in radiation dosimetry for personal, absorbed dose and environmental monitoring.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 E
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• pp.1678-1680
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• 1997

The pulsed power with the high voltage and current can be used to the fields of high speed pulses of energy in different forms such as electric current and voltage, electron beam, ion beam, x-rays, gamma rays, heat, magnetics fields, sound and shock waves. This paper is directed mainly at electrical engineers working on production and practical application of high speed pulsed power with high voltage and current.

• Carbon letters
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• 제15권4호
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• pp.262-267
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• 2014

Pyrolized fuel oil (PFO) was reformed by novel electron beam (E-beam) radiation, and the elemental composition, chemical bonds, average molecular weight, solubility, softening point, yields, and density of the modified patches were characterized. These properties of modified pitch were dependent on the reforming method (heat or E-beam radiation treatment) and absorbed dose. Aromaticity ($F_a$), average molecular weight, solubility, softening point, and density increased in proportion to the absorbed dose of E-beam radiation, with the exception of the highest absorbed dose, due to modification by free radical polymerization and the powerful energy intensity of E-beam treatment. The H/C ratio and yield exhibited the opposite trend for the same reason. These results indicate that novel E-beam radiation reforming is suitable for the preparation of aromatic pitch with a high ${\beta}$-resin content.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.906-909
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• 2006

The secondary electron emission coefficient $({\gamma})$ of the cathode is an important factor for improving the discharge characteristics of AC-PDPs because of its close relationship to discharge voltage. In AC-PDPs, MgO is most widely used as a surface protective layer. In this experimental, we have investigated the electronic structure of the energy band structure of the MgO layer responsible for the high ${\gamma}$. The MgO layers have been deposited by electron beam evaporation method, where the $O_2$ partial pressures have been varied as 0, $5.2{\times}10^{-5}$ torr, $1.0{\times}10^{-4}$ torr, and $4.1{\times}10^{-4}$ torr, in this experiment. It is noted that work function that is energy gap between surface and first defect level of MgO layer has the lowest value for the highest O2 partial pressure of $4.1^{\ast}10^{-4}$ Torr.

• 한국진공학회지
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• 제19권3호
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• pp.199-205
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• 2010

수열합성법(hydrothermal) 방식으로 성장한 ZnO 기판에 고에너지의 전자빔을 조사시킨 후 쇼트키(Schottky)다이오드를 제작하여 결함상태와 전기적 특성 변화를 조사하였다. 1 MeV 및 2 MeV 전자빔으로 $1{\times}10^{16}$ electrons/$cm^2$ dose로 기판의 Zn 면에 조사하였다. 1 MeV 전자빔이 조사된 시료에서는 표면에 전자빔 유도결함을 형성시켜 누설전류를 증가시켰고, 2 MeV 전자빔의 경우는 오히려 다이오드 누설절류 감소와 on/off 특성을 향상시키는 것으로 나타났다. 이들 시료에 대한 DLTS (deep level transient spectroscopy) 측정결과 전자빔 조사에 따른 전기적 물성변화는 활성화에너지와 포획단면적이 각각 $E_c$-0.33 eV 및 $2.97{\times}10^{15}\;cm^{-2}$인 O-vacancy가 주된 연관성을 보였으며, 활성화에너지 $E_v$+0.8 eV인 결함상태도 새롭게 완성되었다.

• 한국진공학회지
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• 제12권3호
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• pp.182-192
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• 2003

밀리미터파 대역용 고속 PHEMT 소자 제작 및 개발을 위하여 다층 리지스트 및 다원자 기판 구조에서 전자빔 리소그래피 공정을 분석할 수 있는 새로운 몬테 카를로 시뮬레이션 모델을 개발하였다. 전자빔에 의해 다층 다원자 타겟 기판 구조에 전이되는 에너지를 정확하고 효율적으로 계산하기 위하여 다층 리지스트 및 다층 다원자 기판 구조에서 시뮬레이션 가능하도록 새로이 모델링하였다. 본 논문에서 제안 개발된 모델을 사용하여 PHEMT 소자의 전자빔 리소그래피에 의한 T-게이트 형성 공정을 시뮬레이션하고 SEM측정 결과와 비교 분석하여 타당성을 검증하였다.

• 한국방사선학회논문지
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• 제17권5호
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• pp.641-649
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• 2023

본 연구에서는 3D 프린팅 기술을 활용하여 제작한 차폐체의 성능을 비교 분석하여, 고에너지 전자선 치료 시 차폐체로서의 적용 가능성에 대해 알아보고자 한다. 고에너지 전자선에 대한 3D 프린팅 재료의 차폐성능 평가를 위해 실측과 몬테카를로 기반의 모의실험을 수행하였다. 첫 번째, 모의실험에 대한 신뢰성 확보를 위해 IAEA의 TRS-398 권고를 참조하여 선원항 평가를 수행하였다. 두 번째, PLA+W (93%) 재료에 대한 차폐 성능 분석을 위해 3D 프린터를 이용하여 시편을 제작하였고, 전자선 에너지에 따른 두께별 차폐율을 평가하였다. 세 번째, PLA+W (93%)와 기존 차폐체 간 차폐 성능 비교 분석을 통해 전자선 치료 시 필요한 차폐 두께를 산정하였다. 연구 결과, 첫 번째, 실측과 모의실험을 통한 선원항 평가 결과, 1% 이내의 오차로 TRS-398 권고를 만족하여 모의실험에 대한 신뢰성을 확보하였다. 두 번째, PLA+W (93%)에 대한 차폐 성능 분석 결과, 6 MeV 전자선은 3.12 mm에서 95% 이상의 차폐율을 나타냈고, 15 MeV 전자선은 10 mm 두께에서 90% 이상의 차폐율을 나타내었다. 세 번째, 모의실험을 통해 PLA+W (93%) 재료와 기존 차폐체 간 비교 분석을 통해 동일 두께 내에서 텅스텐, 납, 구리, PLA+W (93%), 알루미늄 순서로 차폐율이 높은 결과를 나타내었으며, 6 MeV 전자선은 5 mm 이상, 15 MeV 전자선은 10 mm 이상 두께에서 거의 유사한 차폐율을 나타내었다. 향후 본 연구를 통해 고에너지 전자선 치료 시 PLA+W (93%) 재료를 이용한 환자의 맞춤형 차폐체 제작을 위한 기초자료로서 활용될 수 있을 것으로 판단된다.