• 제목/요약/키워드: Neutron beam

검색결과 185건 처리시간 0.03초

중성자 조사용 전기도체의 첨가물 효과 (Effect of Metal Oxide of Ceramic Superconductor for Neutron beam Irradiation)

  • 이상헌;최용
    • 전기학회논문지
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    • 제57권3호
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    • pp.429-432
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    • 2008
  • Much studies have been concentrated to develop the fabrication technique for high critical current density but still there are a lot of gap which should be overcome for large scale application of superconducting materials at liquid nitrogen temperature. The improvement of the critical current can be achieved by forming the nano size defect working as a flux pinning center inside the superconductor. In this paper, the establishment of fabrication condition and additive effects of second elements were examined so as to improve the related properties to the practical use of superconductor.

Neutron Beam Hardening with Heavy Water

  • Onizuka, Y.;Hoshi, M.;Takada, J.;Endo, S.;Uehara, S.;Takatsuji, T.;Utshumi, H.;Kobayashi, T.;Sakurai, Y.;Hayabuchi, N.;Yamaguchi, H.;Takada, M.;Fujikawa, K.;Maeda, N.
    • 한국의학물리학회:학술대회논문집
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    • 한국의학물리학회 1999년도 Japanese Journal of Medical Physics
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    • pp.342-344
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    • 1999
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Properties of the Poisson-power Function Distribution

  • Kim, Joo-Hwan
    • Communications for Statistical Applications and Methods
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    • 제2권2호
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    • pp.166-175
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    • 1995
  • When a neutral particle beam(NPB) aimed at the object and receive a small number of neutron signals at the detector without any errors, it obeys Poisson law. Under the two assumptions that neutral particle scattering distribution and aiming errors have a circular Gaussian distributions that neutral particle scattering distribution and aiming errors have a circular Gaussian distribution respectively, an exact probability distribution of neutral particles vecomes a Poisson-power function distribution. We study and prove some properties, such as limiting distribution, unimodality, stochastical ordering, computational recursion fornula, of this distribution. We also prove monotone likelihood ratio(MLR) property of this distribution. Its MLR property can be used to find a criteria for the hypothesis testing problem.

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Exact poisson distribution in the use of NPB with aiming errors

  • Kim, Joo-Hwan
    • 한국경영과학회:학술대회논문집
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    • 대한산업공학회/한국경영과학회 1995년도 춘계공동학술대회논문집; 전남대학교; 28-29 Apr. 1995
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    • pp.967-973
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    • 1995
  • A neutral particle beam(NPB) aimed at the object and receive a small number of neutron signals at the detector to estimate the mass of an object Since there is uncertainty about the location of the axis of the beam relative to the object, we could have aiming errors which may lead to incorrect information about the object. Under the two assumptions that neutral particle scattering distribution and aiming errors have a circular normal distribution respectively, we have derived an exact probability distribution of neutral particles. It becomes a Poison-power function distribution., We proved monotone likelihood ratio property of tlis distribution. This property can be used to find a criteria for the hypothesis testing problem.

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MC-50 싸이클로트론의 설계 특징과 동작 특성 (Design Features and Operating Characteristics of the MC-50 Cyclotron)

  • Bak, Hae-Ill;Bak, Joo-Shik
    • Nuclear Engineering and Technology
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    • 제21권3호
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    • pp.216-222
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    • 1989
  • 원자력병원에 설치되어 있는 MC-50 싸이클로트론은 중성자 치료와 의학용 동위원소 생산을 위해 가동중에 있다. 본 논문에서는 MC-50의 설계 특징, 기계적 구조, 가동 특성에 대하여 기술하고 있다. 본 싸이클로트론의 최적 가동 조건은 반복적인 운전에 의해 결정되었으며, 내부 빔의 성능은 싸이클로트론 반경의 함수로서 내부 빔의 세기 및 공간 분포 측정을 통해 조사되어졌다. 일상적으로, 인출효율이 61%일 때 40$\mu$A세기의 50 MeV 양성자 빔을 얻었다.

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Effect of gadolinium and boron addition on the texture development and magnetic properties of 23Cr-10NiCu duplex stainless steels

  • Baik, Youl;Kang, Bo Kyeong;Choi, Yong;Woo, Wan Chuck
    • Nuclear Engineering and Technology
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    • 제53권6호
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    • pp.1887-1892
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    • 2021
  • The effect of gadolinium and boron on the texture development and magnetic properties of the texture controlled 23Cr-10NiCu duplex stainless steels were studied to develop a high performance neutron and electromagnetic shielding material. The 23Cr-10NiCu base alloy is composed of 60% of austenite and 40% of ferrite, whereas, the 23Cr-10NiCu-0.5Gd-0.8B modified alloy is composed of 66% of austenite, 27% of ferrite and 7% of CrFeB intermetallic compounds. The gadolinium and boron addition to the 23Cr-10NiCu base alloy increased mechanical properties. Microstructure observation showed that the small addition of 0.5 wt% gadolinium and 0.8 wt% boron to the alloy retarded to form texture at the same hot rolling conditions, and improved the maximum magnetism, residual magnetism and coercive force about 3%, 122% and 120%, respectively.

Bragg-curve simulation of carbon-ion beams for particle-therapy applications: A study with the GEANT4 toolkit

  • Hamad, Morad Kh.
    • Nuclear Engineering and Technology
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    • 제53권8호
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    • pp.2767-2773
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    • 2021
  • We used the GEANT4 Monte Carlo MC Toolkit to simulate carbon ion beams incident on water, tissue, and bone, taking into account nuclear fragmentation reactions. Upon increasing the energy of the primary beam, the position of the Bragg-Peak transfers to a location deeper inside the phantom. For different materials, the peak is located at a shallower depth along the beam direction and becomes sharper with increasing electron density NZ. Subsequently, the generated depth dose of the Bragg curve is then benchmarked with experimental data from GSI in Germany. The results exhibit a reasonable correlation with GSI experimental data with an accuracy of between 0.02 and 0.08 cm, thus establishing the basis to adopt MC in heavy-ion treatment planning. The Kolmogorov-Smirnov K-S test further ascertained from a statistical point of view that the simulation data matched the experimentally measured data very well. The two-dimensional isodose contours at the entrance were compared to those around the peak position and in the tail region beyond the peak, showing that bone produces more dose, in comparison to both water and tissue, due to secondary doses. In the water, the results show that the maximum energy deposited per fragment is mainly attributed to secondary carbon ions, followed by secondary boron and beryllium. Furthermore, the number of protons produced is the highest, thus making the maximum contribution to the total dose deposition in the tail region. Finally, the associated spectra of neutrons and photons were analyzed. The mean neutron energy value was found to be 16.29 MeV, and 1.03 MeV for the secondary gamma. However, the neutron dose was found to be negligible as compared to the total dose due to their longer range.