• Title/Summary/Keyword: 산란 중성자

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중성자 산란을 이용한 나노기공 측정

  • 최성민;이지환;조성민
    • Proceedings of the Korea Crystallographic Association Conference
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    • 2002.11a
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    • pp.51-51
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    • 2002
  • 나노기공물질은 특정 기반물질(matrix) 내부에 대략 나노미터크기의 기공을 함유하고 있는 물질이며 나노기공물질의 특성은 기반물질의 특성과 더불어 기공의 형태, 크기, 분포에 의해서 결정된다. 나노기공물질의 기공에 대한 정보를 측정하는 방법으로는 TEM, 흡착법, FE-SEM과 더불어 중성자 또는 X-ray 빔의 산란을 이용하는 소각중성자산란 (Small-Angle Neutron Scatering, SANS), 소각 X-ray 산란 (Small-Angle X-ray Scattering, SAXS), 중성자반사율측정 (Neutron Relfectimetry, NR), X-ray 반사율측정 (X-Ray Reflectometry, XRR) 등이 사용되고 있다. 본 발표는 대략 1 nm - 100 nm 영역의 bulk 구조와 층상구조를 측정할 수 있는 소각 중성자 산란과 중성자 반사율 측정기법을 이용한 나노기공 측정기술을 다룬다.

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MCNPX Simulation of Scattered Neutron Distribution in Experimental Room for the Neutron Reference Field of Monoenergetic Neutron below 2.5 MeV (2.5 MeV 이하 단색 중성자 표준장에 대한 중성자 실험실내의 산란 중성자 분포 전산모사)

  • Park, Jung-Hun;Kim, Gi-Dong
    • Journal of Radiation Protection and Research
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    • v.36 no.2
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    • pp.59-63
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    • 2011
  • It is important to reduce indirect scattered neutron beside direct neutron of chosen energy for designing a neutron-reference-field laboratory with neutron produced from a nuclear reaction by a accelerator. Therefore MCNPX simulation was performed with various conditions for obtaining such condition. At first in the original laboratory condition we calculated the direct neutron flux which was inserted in chamber (virtual chamber composed of air) of 0 degree (proton moving direction) for neutron flux measurement and the scattered neutron flux which is inserted in the chamber after scattering wall or bottom. In the result, the scattered neutron which was inserted after scattering bottom is more than that which was inserted after scattering the others. Therefore MCNPX simulation was again performed with removing the concrete bottom and with removing the concrete bottom and digging 1 m in the ground. In the result of removing concrete bottom and digging 1 m in the ground, scattered neutron which was inserted after scattering bottom became less than that which was inserted after scattering the others.

Comparison Study of Experimental Neutron Room Scattering Corrections with Theoretical Corrections in RCL's Calibration Facility at KAERI (한국원자력연구소 중성자교정실에 대한 중성자산란보정인자 결정연구)

  • Yoon, Suk-Chul;Chang, Si-Young;Kim, Jong-Soo;Kim, Jang-Lyul;Kim, Bong-Hwan
    • Journal of Radiation Protection and Research
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    • v.22 no.1
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    • pp.29-33
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    • 1997
  • Neutron room scattering corrections that should be made when neutron detectors are calibrated with a $D_2O$ moderated $^{252}Cf$ neutron source in the center of a calibration room are considered. Such room scattering corrections are dependent on specific neutron source type, detector type, calibration distance, and calibration room configuration. Room scattering corrections for the responses of a thermoluminescence dosimeter and two different types of spherical detectors to neutron source in the Radiation Calibration Laboratory(RCL) neutron calibration facility at the Korea Atomic Energy Research Institute(KAERI) were experimentally determined and are presented. The measured room scattering results are then compared with theoretical results calculated by predicting room scattering effects in terms of parameters related to the specific configuration. Agreement between measured and calculated scattering correction is generally about 10% for three kinds of detectors in the calibration facility.

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Introduction to Neutron Scattering for Magnetic Materials Research (자성소재 연구를 위한 중성자산란 입문)

  • Jeong, Jae-Hong;Lee, Sang-Hyun;Park, Je-Geun
    • Journal of the Korean Magnetics Society
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    • v.22 no.3
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    • pp.103-108
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    • 2012
  • Having a de Broglie wavelength of a few ${\AA}$ with its corresponding energies in the range of a few to a few hundreds meV, neutrons are ideally suited for the studies of structure and dynamics in condensed matter research. Neutron scattering has been developed over the past 60 years or so and become a very mature and established experimental technique in the very broad range of material sciences. In this short introductory article, we have explained its working principles and provided few selected examples of application.

A Computer Code DEUKER for $D_2$O Scattering cross Section

  • Shu, Soo-Hyun;Kim, Seong-Yun;Kim, Dong-Hoon
    • Nuclear Engineering and Technology
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    • v.10 no.3
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    • pp.145-151
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    • 1978
  • Based on the Butler scattering kernel for D$_2$O, a computer code DEUKEB has been developed to compute the scattering laws, differential scattering cross sections and total scattering cross sections. Interference scattering between ally two atoms of a D$_2$O molecule is important in resolving the distribution of scattered neutrons in thermal energy region. Energy-transfer scattering cross sections are, therefore, studied in the various incident neutron energies. This study may be put in practice to utilize the kernel in determining the neutron spectrum in a reactor system. The study also shows that the scattering process in D$_2$O is somewhat different from that in $H_2O$.

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Scattering Effectiveness of Monoenergetic Neutrons in the Various Shielding Materials

  • Yoo, Young-Soo
    • Nuclear Engineering and Technology
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    • v.4 no.1
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    • pp.39-45
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    • 1972
  • In neutron shielding, the scattering effect is equally important as the attenuations in shielding materials. In the present study, the scattered dose equivalent was measured using a Rem counter for water, paraffin, borated paraffin, ordinary and heavy concrete, lead, iron, and tissue equivalent material in three different angles: 45$^{\circ}$, 90$^{\circ}$, and 135$^{\circ}$, respectively. The measurements were performed for the neutron, having the energies of 0.5, 1, 2, 5, and 18 MeV, which are produced from the Van do Graaff accelerator. The scattered dose equivalent ratios were increased with increasing the thickness of scattering materials and saturated at a certain thickness although they were different from one to other materials under study. The ratios were large for lead and iron while they were small for the hydrogen containing materials such as water and paraffin etc.

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Mosaics of $KMnCl_3$ undoped and Mg-doped $LiNbO_3$ single crystals measured by neutron scattering (중성자 산란을 이용한 $KMnCl_3$, $LiNbO_3$$Mg-LiNbO3$단결정의 mosaic 연구)

  • 양용석
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.5 no.2
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    • pp.129-134
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    • 1995
  • Bulk properties of single crystals $KMnCl_3$ undoped and Mg- doped $LiNbO_3$ were examined by using the neutron scattering technique. This study shows that the good -looking samples by polarized light have to be examined by the. neutron scattering to ensure the bulk properties of single crystal. Large mosaic spread in KMnCb indicated the crystal is not in a single domain. Many parts are relatively randomly directed against crystal axis with close angle each other. For the small mosaic spread of Li~ in the scattering pattern, it is found that some large domains have close orientations. Mg doped Li~ is turned out to be a well grown one.

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연구용 원자로 하나로와 녹색성장

  • Im, In-Cheol;Kim, Myeong-Seop;Seong, Baek-Seok;Lee, Gi-Hong;Kim, Tae-Ju;Lee, Hui-Ju
    • Journal of the KSME
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    • v.49 no.11
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    • pp.45-51
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    • 2009
  • 한국원자력연구원의 다목적 연구용 원자로, 하나로는 중성자 이용 물성 연구 등 다양한 분야에 사용되며, 중성자는 녹색기술 관련 소재의 생산과 특성 분석에 매우 유용한 도구이다. 중성자 도핑을 이용하여 생산되는 반도체는 그린 카에 사용되는 전력 소자에 활용되고 있다. 중성자 산란 실험 장치들은 이차전지 재료와 수소저장 물질의 물성 연구에 활용되고 있다. 중성자 비파괴 검사 장치는 연료전지의 성능 연구에 활용되고 있다. 고속중성자를 이용하여 스위칭 소자의 특성을 개선하는 기술과 장치가 구축되면 전력 소자의 효율 증대에 기여할 것이다.

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