• 제목/요약/키워드: Electron-Beam Energy

검색결과 691건 처리시간 0.029초

가우시안 근사를 이용한 6 MeV 전자선의 에너지분포에 관한 연구 (Study on Energy Distribution of the 6 MeV Electron Beam using Gaussian Approximation)

  • 이정옥;김승곤
    • 대한방사선기술학회지:방사선기술과학
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    • 제22권2호
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    • pp.53-56
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    • 1999
  • A Gaussian distribution was parametrized for the initial distribution of the electron beam emitted from a 6MeV medical linear accelerator. A percent depth dose was measured in a water phantom and the corresponding Monte Carlo calculations were performed starting from a Gaussian distribution for a range of standard deviations, ${\sigma}=0.1$, 0.15, 0.2, 0.25, and 0.3 with being the mean value for the Incident beam energy. When measurement and calculation were compared, the calculation with the Gaussian distribution for ${\sigma}=0.25$ turned out to agree best with the measurement. The results from the present work can be utilized as input energy data in planning an electron beam therapy with a Monte Carlo calculation.

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Electron Beam Effects on Lignin Stabilization during Carbonization

  • Lee, Byoung-Min;Kang, Phil-Hyun;Jeun, Joon-Pyo
    • 방사선산업학회지
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    • 제7권2_3호
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    • pp.167-170
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    • 2013
  • Lignin can be a valuable natural chemical resource. Structurally, lignin is a three-dimensional polymer made up of condensed C-C bonds and some ether linkages, most of which are not readily degraded. In this study, lignin carbonization under various electron beam pretreatment conditions was characterized through a thermogravimetric analysis (TGA), X-ray diffraction (XRD) and Raman spectroscopy. Lignin stabilization was controlled by various doses of electron beam irradiation corresponding to 50, 100, 200, 500 and 1,000 kGy; the carbonization process was performed under a nitrogen gas atmosphere at $1000^{\circ}C$ for 1 h. The TGA results showed that a 1,000 kGy lignin dose increased the residue weight from 39.96% to 45.23%, compared to non-irradiated lignin. This observation is in agreement with the XRD and Raman spectroscopy results, in which the two theta degrees and the degree of crystallization were improved by increasing the electron beam irradiation.

OPTIMIZATION OF OPERATION PARAMETERS OF 80-KEV ELECTRON GUN

  • Kim, Jeong Dong;Lee, Yongdeok;Kang, Heung Sik
    • Nuclear Engineering and Technology
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    • 제46권3호
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    • pp.387-394
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    • 2014
  • A Slowing Down Time Spectrometer (SDTS) system is a highly efficient technique for isotopic nuclear material content analysis. SDTS technology has been used to analyze spent nuclear fuel and the pyro-processing of spent fuel. SDTS requires an external neutron source to induce the isotopic fissile fission. A high intensity neutron source is required to ensure a high for a good fissile fission. The electron linear accelerator system was selected to generate proper source neutrons efficiently. As a first step, the electron generator of an 80-keV electron gun was manufactured. In order to produce the high beam power from electron linear accelerator, a proper beam current is required form the electron generator. In this study, the beam current was measured by evaluating the performance of the electron generator. The beam current was determined by five parameters: high voltage at the electron gun, cathode voltage, pulse width, pulse amplitude, and bias voltage at the grid. From the experimental results under optimal conditions, the high voltage was determined to be 80 kV, the pulse width was 500 ns, and the cathode voltage was from 4.2 V to 4.6 V. The beam current was measured as 1.9 A at maximum. These results satisfy the beam current required for the operation of an electron linear accelerator.

화학적 특성검지에 의한 지방산 고함유 농산물의 저장기간에 따른 전자선 조사 여부 검지 (Determination of Electron Beam-Irradiation by the Chemical Detection Methods According to Storage Period in Fat-riched Agricultural Products)

  • 김동용;백지영;류형원;진창현;최대성;육홍선;변명우;정일윤
    • 방사선산업학회지
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    • 제5권4호
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    • pp.297-303
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    • 2011
  • The purpose of this research is to detect whether agricultural products were electron beam irradiated or non-irradiated by chemical methods according to increase of storage period. The three fat-rich samples including soybean, walnut, and sesame were chosen as agricultural products, and then were irradiated with doses of 1~10 kGy by using 10 MeV electron beam facility. At the result, 8-heptadecene and 1,7-hexadecadiene, which are indicators of electron beam-irradiation in chemical methods by gas chromatography/mass spectrometry(GC/MS) method, were detected in all three samples. The levels of two irradiation indicators were increased by electron beam-irradiation in a dose-dependent manner. Furthermore, two irradiation indicators also were detected in all samples in 6 and 12 months after irradiation, though levels of those were decreased in a time-dependent manner. These results mean that the quantification of 8-heptadecene and 1,7-hexadecadiene could determine whether electron beam were irradiated or non-irradiated until 12 month after irradiation in 3 fat-rich agricultural products including soybean, walnut, and sesame.

Differential Modulation of Volatile Constituents in Artemisia princeps and Artemisia argyi Plants after Gamma Ray or Electron Beam Irradiation

  • Kim, Ji Hong;Cho, Eun Ju;Lee, Min Hee;Kim, Ji Eun;Chung, Byung Yeoup;Kim, Tae Hoon;Kim, Jin-Hong
    • 방사선산업학회지
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    • 제6권1호
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    • pp.17-21
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    • 2012
  • The effects of gamma ray or electron beam irradiation on herbaceous medicinal plants were investigated in terms of the composition of volatile constituents using the aerial parts or leaves of Artemisia princeps Pamp. cv. Ganghwayakssuk and Artemisia argyi cvs. Namhaeyakssuk and Hwanghaessuk. The composition of volatile constituents in leaves was clearly distinguishable among the three Artemisia cultivars. However, the relative proportions of the major volatile constituents such as 1,8-cineole, ${\alpha}$-pinene, camphene, santolina triene, and artemesia triene, were similarly changed in two or three cultivars by gamma ray or electron beam irradiation. In particular, the proportion of 1,8-cineole was increased up to 1.29- to 1.71-fold in the three cultivars after irradiation with gamma ray. These results suggest that gamma ray or electron beam irradiation can be applied to modulate the composition of volatile constituents in the leaves of Artemisia plants.

Degardatrion of Cellulosic Fibers by Electron Beam Irradiation

  • Han, Sung-Ok;Seo, Yung-Bum;Lee, Chun-Han
    • 펄프종이기술
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    • 제39권5호
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    • pp.20-25
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    • 2007
  • Henequen fibers were treated by electron beam irradiation and by NaOH to make surface modification for better bonding in the manufacture of biocomposite. Impurity removal and carbonyl group formation were noticed in the previous study by electron beam irradiation, but extensive cellulose degradation were also noticed. To evaluate the effects of electron beam irradiation on cellulosic fibers further, henequen fibers, cotton pulp, cotton fibers, and cellophane were irradiated by electron beam, and their changes of cellulose viscosity, chemical composition, and tensile strength were measured and analyzed.

GEANT4를 이용한 선형가속기 기초 코드 작성과 전자선 에너지 분포 계산 (Calculation of Energy Spectra for Electron Beam of Medical Linear Accelerator Using GEANT4)

  • 조영걸;김형동;김병용;김성진;오세안;강정구;김성규
    • 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.

Electron Beam 조사가 인삼분말의 색도 및 관능적 품질에 미치는 영향 (Effects of Electron-Beam Irradiation on Color and Organoleptic Qualities of Ginseng Powders)

  • 이미경;권중호;도재호
    • Journal of Ginseng Research
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    • 제22권4호
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    • pp.252-259
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    • 1998
  • Electron beam, electrically produced from an electron accelerator, was compared with gamma energy in terms of its influence on color and organoleptic qualities of ginseng powders when exposed to the energy used for their microbial decontamination. Hunter color L and b values were suitable for measuring color characteristics of ginseng powders, which were not significantly changed by the exposure to 5 to 7.5 kGy electron beam and gamma energy. Fifty percent ethanol extracts of irradiated ginseng powders at 10 key showed negligible differences from the non-irradiated control in the pattern of absorption spectra at 280∼800 am, but showed increased values in overall color difference (AE) as compared with powdered samples. Irradiation more than 10 kGy and storage at ambient temperature for 4 months caused browning of powdered samples. Irradiation at more than 10 kGy of electron beam was found a critical level to bring about appreciable changes (p<0.05) in or-ganoleptic qualities such as color and odor of sterilized samples, and red ginseng powder was more susceptible than white one to organoleptic changes by irradiation.

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저에너지 대면적 전자빔 발생장치 개발에 관한 연구 (A Study on the Low-energy Large-aperture Electron Beam Generator)

  • 조주현;최영욱;이홍식;임근희;우성훈;이광식
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제48권12호
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    • pp.785-790
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    • 1999
  • This research has been carried out to develop a low-energy large-aperture pulsed electron beam generator (LELA), 200keV 1A, for industrial applications. One of the most important feature of this electron beam generator is large electron beam cross section of $190cm^2$. Low energy electron beam generators have been used for water cleaning, flue gas cleaning, and pasteurization, etc. In these applications the cross sectionof the e-beam is related to reaction efficiency. Another important feature of this LELA EB generator is easy maintenance because of its simple structure and relatively low vacuum operation compared to the conventional EB generators. The conventional EB generators need to be scanned because the small cross section thermal electron emitters are used in the conventional EB generators which have small EB cross section. In this research, we use the secondary electrons generated by ion bombardment on the HV cathode surface as a electron source. Therefore we can make any shape of EB cross section without scanning.

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고분자 표면의 전자빔 조사에 따른 젖음특성 고찰 (Investigation of Wetting Characteristics of Polymer Surfaces according to Electron Beam Irradiation)

  • 이현중;박근;김병남
    • 한국정밀공학회지
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    • 제33권1호
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    • pp.45-51
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    • 2016
  • The present study uses an electron beam (e-beam) to modify the wetting characteristics of thermoplastic polymer surfaces. A high energy e-beam irradiated various polymer surfaces (PET, PMMA, and PC), with variations in irradiation time and applied current. The water contact angles were measured on the e-beam irradiated surfaces in order to investigate the changes in the surface energy and the relevant wettability. Furthermore, XPS analyses were performed to investigate the chemical composition change in the e-beam irradiated surfaces; the results showed that the hydrophilic groups (C-O) increased after the electron beam irradiation. Also, water collection tests were performed for various polymer samples in order to investigate the effect of the surface energy on the ability of water collection, from which it can be seen that the irradiated surfaces revealed better water-collecting capability than pure polymer surfaces.