• Journal of Radiation Protection and Research
• /
• 제35권3호
• /
• pp.105-110
• /
• 2010

고순도 반도체 감마분광시스템을 이용하여 토양 시료를 파괴하지 않고 화학 전처리 단계가 필요없는 우라늄 방사능 분석 기술을 개발하였다. 본 논문에서 제시한 방법을 이용한 분석결과와 기존에 일반적으로 사용하는 알파분광분석법(Alpha Spectrometry)의 결과를 비교하였다. 비교결과 불확도 범위 내에서 비슷한 측정값을 보였다. 따라서 본 논문에서 제시한 방법은 토양시료의 우라늄 분석에 이용될 수 있을 것이다.

• 한국원자력학회:학술대회논문집
• /
• 한국원자력학회 2001년도 추계학술발표회요약집
• /
• pp.318.1-318
• /
• 2001

• Nuclear Engineering and Technology
• /
• 제35권4호
• /
• pp.347-355
• /
• 2003

The \gamma-ray spectrometer of the PGAA (Prompt Gamma Activation Analysis) facility constructed at HANARO of the Korea Atomic Energy Research Institute was upgraded to the multi-mode spectrometer including the single mode, the Compton suppression mode and the pair mode. The performance of the spectrometer was tested and summarized. The background count rate and the uncertainty of the detection efficiency were reduced greatly in comparison with those before the new installation.

• Journal of Astronomy and Space Sciences
• /
• 제31권4호
• /
• pp.317-323
• /
• 2014

Odyssey, one of the NASA's Mars exploration program and SELENE (Kaguya), a Japanese lunar orbiting spacecraft have a payload of Gamma-Ray Spectrometer (GRS) for analyzing radioactive chemical elements of the atmosphere and the surface. In these days, gamma-ray spectroscopy with a High-Purity Germanium (HPGe) detector has been widely used for the activity measurements of natural radionuclides contained in the soil of the Earth. The energy spectra obtained by the HPGe detectors have been generally analyzed by means of the Window Analysis (WA) method. In this method, activity concentrations are determined by using the net counts of energy window around individual peaks. Meanwhile, an alternative method, the so-called Full Spectrum Analysis (FSA) method uses count numbers not only from full-absorption peaks but from the contributions of Compton scattering due to gamma-rays. Consequently, while it takes a substantial time to obtain a statistically significant result in the WA method, the FSA method requires a much shorter time to reach the same level of the statistical significance. This study shows the validation results of FSA method. We have compared the concentration of radioactivity of $^{40}K$, $^{232}Th$ and $^{238}U$ in the soil measured by the WA method and the FSA method, respectively. The gamma-ray spectrum of reference materials (RGU and RGTh, KCl) and soil samples were measured by the 120% HPGe detector with cosmic muon veto detector. According to the comparison result of activity concentrations between the FSA and the WA, we could conclude that FSA method is validated against the WA method. This study implies that the FSA method can be used in a harsh measurement environment, such as the gamma-ray measurement in the Moon, in which the level of statistical significance is usually required in a much shorter data acquisition time than the WA method.

• Nuclear Engineering and Technology
• /
• 제52권5호
• /
• pp.1036-1042
• /
• 2020

Fast-Neutron Multiplicity Counter based on Liquid Scintillator Detector can directly measure the fast neutron multiplicity emitted by UO₂ rod. HPGe gamma spectrometer; which has superior energy resolution; is routinely used for the gamma energy spectrum measurement. Combing Fast-Neutron Multiplicity Counter and HPGe γ-spectrometer, the n/γ joint measurement system is developed. The fast neutron multiplicity and gamma energy spectrum of UO₂ rod assemblies under different conditions are measured by the n/γ joint measurement system. The induced fission rate and the ²³⁵U abundance, thereby the ²³⁵U mass; can be obtained for UO₂ rod assemblies. The ²³⁵U mass deviation of the measured value from the reference value is less than 5%. The results show that the n/γ joint measurement system is effective and applicable in the measurement of the ²³⁵U mass in samples.

• 방사성폐기물학회지
• /
• 제12권2호
• /
• pp.97-105
• /
• 2014

HPGe 감마선 검출기를 이용하여 $^{226}Ra$의 방사능을 직접 측정방법의 경우, $^{226}Ra$의 186.21 keV 감마선이 $^{235}U$에서 방출되는 185.7 keV 감마선에 의한 간섭을 받기 때문에 피크면적의 계산에서 반드시 보정이 필요하다. 비록 분해능이 아주 우수한 HPGe 검출기를 사용한다 하더라도 그리고 분광시스템의 채널수를 최대로 늘린다고 할지라도 약 0.5 keV 차이의 두 감마선 피크를 분리해 내기란 현실적으로 어려운 일이다. 본 연구에서는 감마분광분석을 이용한 $^{226}Ra$의 직접 측정방법에 대한 적용성을 평가하기 위하여, 여러 가지 간섭피크 보정들을 이용한 직접 측정방법을 조사하였다. 이를 원료물질 및 공정부산물 시료들에 적용함으로써 직접 측정방법들에서 그 측정 불확도, 직선성 및 적용범위 등을 평가하였다. 최종적으로 방사평형 관계를 이용하여 $^{226}Ra$의 방사능을 측정하는 간접 측정방법으로부터 얻은 $^{214}Pb$ 및 $^{214}Bi$의 결과를 직접 측정방법의 결과와 비교함으로써 최적의 측정방법을 유도하였다.

• 분석과학
• /
• 제16권5호
• /
• pp.426-429
• /
• 2003

Neutron induced prompt gamma-ray spectroscopy (NIPS) system equipped with a $^{252}Cf$ neutron source and a n-type coaxial HPGe detector was installed for the quantitative analysis of aqueous samples in KAERI, Korea. Since the thermal neutron flux for the $^{252}Cf$ neutron source is relatively low compared to that for the reactor, the use of a thermal neutron reflector in the NIPS system may lead to improved results. The enhancement by using various reflectors was carried out by comparing the Cl peak with or without a cadmium plate between sample and the $^{252}Cf$ source. The use of pyrolitic graphite as a reflector provided a good result.

• 한국방사선학회논문지
• /
• 제7권1호
• /
• pp.31-36
• /
• 2013

우라늄($^{238}U$)의 붕괴과정에서 생성되는 방사성기체인 라돈($^{222}Rn$)은 발생원 중 토양에서 85 % 이상으로 토양의 공극률이 클수록 토양 밖으로 방출할 수 있는 가능성이 많은 동위원소이다. 라돈으로부터 인체를 보호하기 위해서 적절한 대책을 세우는데 무엇보다도 정확한 측정기술의 개발이 선행되어야 한다. 이에 본 연구는 고순도게르마늄(HPGe) 검출기를 이용한 감마선 분광분석법으로 라돈을 측정할 경우에는 불안정한 자연방사능의 백그라운드 문제를 줄일 수 있고, 라듐과 라돈의 딸 핵종들을 방사평형에 이르게 한 후 라돈 농도를 측정하였으며, 토양시료에서의 감마선 방출핵종 및 에너지 스펙트럼을 분석하였다.

• Nuclear Engineering and Technology
• /
• 제56권2호
• /
• pp.477-484
• /
• 2024

Experimental investigations on gamma - rays attenuation parameters and dielectric spectroscopic properties were done on a polymeric mixture with chemical composition (100-x) polyethylene + x basalt, where x = 0, 1, 3, 5, 10, and 20 wt%. Using the melting blending technique,six nanocomposite polymeric samples were prepared. The linear attenuation coefficient µ of each prepared set of samples was measured using a gamma-ray spectrometer including High Purity Germanium detector (HPGe) at energies 662.5, 1173.24, and 1332.51 keV. Based on the measured values of (µ) and sample density, the other effective shielding parameters were calculated. The values of µ showed an increase with increasing the dopant ratios from 0.0 up to 20.0 wt%. In addition, the µ values decreased with the photon's energy. The µ values were found 0.0847 up to 0.1175 cm^-1, 0.0571 up to 0.0855 cm^-1, and 0.0543 up to 0.075 cm^-1 at 662.5, 1173.24, and 1332.51 keV. for B0 up to B20, respectively. The ATR spectroscopy was done on the prepared samples, and a good evidence of adding the filler to the pure polyethylene (HDPE) was obtained. Besides, an enhancement in dielectric constant by insertion of basalt NPs also recorded and can be attributed to the large dielectric constant of basalt compared to pure HDPE.

• 방사성폐기물학회지
• /
• 제5권4호
• /
• pp.267-272
• /
• 2007

RI 폐기물 내에 있는 낮은 방사능의 요오드의 함량을 결정하기 위해 산분해법과 BPGe 감마 선분광계를 이용하는 방법이 개발되었다. 분석에 앞서 모의시료인 제염지 내에 $^{131}I$이 일정량 첨가되었으며, 100 mL의 0.4 N $K_2Cr_2O_7$와 100 mL의 9 M $H_2SO_4$, 10 mL의 30% $H_3PO_3$, 1 mL의 $H_2O_2$를 넣고 산분해과정을 거치면서 증류된 용액을 응축하여 포집하였다. $CCl_4$의 용매추출에 의한 화학 분리과정을 거친 후 $AgNO_3$를 첨가해서 얻은 AgI 침전물을 여과하고 건조하여 측정하였다. 산분해 과정, 화학 분리과정, 여과 및 침전과정 등 세 단계로 나눠 회수율을 측정한 결과, 각각 94% 이상의 회수율을 나타냈으며, 본 연구의 측정조건에서 최소검출방사능은 0.6 Bq/g이었다.