• Journal of Radiation Protection and Research
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• 제22권1호
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• pp.29-33
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• 1997

중성자교정실내에서 $D_2O$ 감속 $^{252}Cf$중성자선원을 사용하여 계측기를 교정할 때는 그 계측기에 대한 교정실산란보정 인자를 미리 결정하여야 한다. 이러한 교정실산란보정인자는 계측기의 종류, 교정거리, 교정실형태에 따라 다르게 결정된다. 본 연구에서는 한국원자력연구소에서 운영하는 2차 표준중성자교정실에서 한가지의 열형광선량계와 2가지의 구형검출기에 대한 교정실산란보정인자를 실험적으로 결정하였고 본소의 2차 표준중성자교정실조건에 의하여 이론적으로 예측한 값과 비교하였다. 비교한 결과 실험하여 얻어진 상기의 3가지 계측기에 대한 교정실산란보정인자가 이론적으로 예측한 결과와 최대 약 10% 이내에서 일치하였다.

• Nuclear Engineering and Technology
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• 제47권7호
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• pp.939-944
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• 2015

The calibration methods of neutron-measuring devices such as the neutron survey meter have advantages and disadvantages. To compare the calibration factors obtained by the shadow cone method and semi-empirical method, 10 neutron survey meters of five different types were used in this study. This experiment was performed at the Korea Atomic Energy Research Institute (KAERI; Daejeon, South Korea), and the calibration neutron fields were constructed using a $^{252}Californium$ ($^{252}Cf$) neutron source, which was positioned in the center of the neutron irradiation room. The neutron spectra of the calibration neutron fields were measured by a europium-activated lithium iodide scintillator in combination with KAERI's Bonner sphere system. When the shadow cone method was used, 10 single moderator-based survey meters exhibited a smaller calibration factor by as much as 3.1-9.3% than that of the semi-empirical method. This finding indicates that neutron survey meters underestimated the scattered neutrons and attenuated neutrons (i.e., the total scatter corrections). This underestimation of the calibration factor was attributed to the fact that single moderator-based survey meters have an under-ambient dose equivalent response in the thermal or thermal-dominant neutron field. As a result, when the shadow cone method is used for a single moderator-based survey meter, an additional correction and the International Organization for Standardization standard 8529-2 for room-scattered neutrons should be considered.