• 대한방사선방어학회:학술대회논문집
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• 2011.04a
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• pp.98-99
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• 2011

• Journal of Radiation Protection and Research
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• v.38 no.2
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• pp.119-123
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• 2013

A simple laboratory-made radioactive source to check the integrity of a gamma spectrometry system with HPGe detector was developed. The check source consists of radium-riched soil which was ground in size of less than 0.154mm and contained in air tight cylinderical vial, and provides photons with 12 distinct energies. The spectra of the check source were measured once a month during one year, analyzed the charactreictics of their peaks. When the gamma spectrometry system was in normal state, the areas and FWHMs of the gamma rays with more than 3% gamma emission rate in radium and its decay products was constant within standard deviation 2% and 3%, respectively, except 77 keV peak. And it was found that this check source can play a sufficient role to check the integrity of a gamma spectrometry system using 10 peaks in the range of 77 to 2202 keV.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.12 no.2
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• pp.97-105
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• 2014

In the case of the direct measurement of $^{226}Ra$ using a HPGe gamma-ray spectrometer, the interference between gammarays with 186.21 keV of $^{226}Ra$ and 185.7 keV of $^{235}U$ should be corrected to calculate the net peak area in the energy spectrum. In general, it is very difficult to conduct peaks stripping with difference of about 0.5 keV, although a HPGe with the superior resolution is applied and the maximum channels is applied to the spectrometer. In this study, several interference correction techniques in the direct measurement were surveyed to evaluate the feasibility for the measurement of $^{226}Ra$ using the gamma-ray spectrometery. Applying the interference corrections to the analysis of raw materials and by-products, the method validation for the direct measurement of $^{226}Ra$ was conducted by evaluating the measurement uncertainty, linearity, and range. As a result, the optimum method of the interference correction was selected by comparing with the indirect measurement of which progenies of $^{226}Ra$, such as $^{214}Pb$ and $^{214}Bi$, were analyzed in the secular equilibrium state.

• Journal of the Korean Society of Radiology
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• v.13 no.5
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• pp.819-824
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• 2019

In this study, we proposed a method for identifying isotopes generated from high-energy proton $^{nat}Pb$(p,xn) nuclear reactions through the difference of gamma rays generated through nuclear reactions using different proton energies. The experiment was performed by using a high energy proton generated from a 100 MeV proton linear accelerator of the Korea Atomic Energy Research Institute. Gamma rays generated by various nuclides generated through proton nuclear reactions were measured using a gamma-ray spectroscopy system composed of HPGe detectors. Gamma-ray standard sources were used for accurate energy calibration and efficiency measurements of HPGe gamma-ray detectors. For the proposed method, 100 and 60 MeV proton energy beams were used for the same natural lead samples. This method was found to be very effective in identifying nuclides produced by comparing gamma rays generated from the same sample with each other. The results of this study are expected to be very effective in obtaining other proton nuclear reaction results in the future.

• Journal of the Korean Society of Radiology
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• v.7 no.1
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• pp.31-36
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• 2013

The radioactive gas radon ($^{222}Rn$), which is generated from the decay process of uranium ($^{238}U$) originating from the soil of more than 85 percent higher the porosity of the soil, the soil can radiate out the possibility that many isotopes. In order to protect the human body from radon, above all, the development of accurate measurement techniques to formulate appropriate measures should be followed. This study Gamma-ray spectrometry using a high purity germanium (HPGe) detector, if you want to measure radon unstable the nature radiation of the background problems can be reduced, radium and radon daughter nuclides after radioactive equilibrium leads to Radon concentration was measured, the soil samples from the Gamma-ray emitting nuclides, and the energy spectrum is analyzed.

• Journal of the Korean Society of Radiology
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• v.11 no.3
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• pp.123-129
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• 2017

Compton suppression apparatus using the Compton scattering response, by inhibiting part of the spectrum Compton continuum Compton continuum in the area of the peak analysis of the gamma rays that enables a clearer device. In order to find out the geometry structure of high-purity germanium detector(HPGe) -NaI(TI) and to optimize the effect of movement, Monte Carlo simulation was used to grasp the behavioral characteristics of Compton suppression and compare several layout structures. And applied to the cylinder beaker used for the environmental measurement by using the efficiency according to the distance. For the low-energy source such as 81 keV, the Compton continuum is scarcely developed and the suppression effect is also insignificant because the scattering cross-section of the Compton effect is relatively low. In the spectrum for the remaining energy, it can be seen that the Compton continuum part is suppressed in a certain energy range. Compton suppression effect was not significantly different from positional shift. average reduction factor(ARF) value was about 1.08 for 81 keV and about 1.23 for 1332.4keV energy at the highest value. It can be seen that suppression over the Compton continuum region of the energy spectrum is a more appropriate arrangement. Therefore, it can be applied to various environmental sample measurement through optimized structure.

• Journal of the Korean Society of Radiology
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• v.12 no.2
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• pp.133-138
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• 2018

The measurement of gamma-ray spectrum of $^{nat}W(p,xn)$ reaction with natural tungsten were performed by using a high energy proton generated from a 100-MeV proton linear accelerator of the Korea Multi-purpose Accelerator Complex (KOMAC). Gamma rays generated by various nuclides generated through the nuclide were measured using a gamma-ray spectroscopy system composed of HPGe detector. A gamma-ray standard source was used for energy calibration and efficiency measurement of the detector. Analysis of the gamma rays observed in the measured spectra showed that the radionuclides produced were $^{167}Re$, $^{178}Re$, $^{179}Re$, $^{180}Re$, $^{181}Re$, $^{182}Re$, $^{184}Re$, $^{172}Ta$, $^{174}Ta$, $^{178}Ta$, $^{182}Ta$, $^{184}Ta$, $^{175}W$, $^{176}W$, $^{177}W$ and $^{179}W$. Nuclides were generated. The results of this study will be applied to nuclear fusion, astrophysics, and nuclear medicine applications in the future.

• Journal of the Korean Society of Radiology
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• v.12 no.5
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• pp.557-563
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• 2018

Coincidence summing correction effects are known to be greater as the efficiency of the detector increases and as the distance between the source and the detector increases. A point source($^{60}Co$) was used to vary the distance in the direction of the detector's center axis and in the radial direction to obtain the P/T ratio for Coincidence summing correction calibration. In this study, values for coincidence summing corrected calibration of the values in the central and radial directions were applied to the mixed volume source(450 ml CRM source) to compare the overall peak efficiency change according to P/T with Geant4. In addition, the efficiency obtained from the mapping method is applied to the seaweed, a marine sample, and the compatibility of the P/T ratio with the detector and sample very dose together. The efficiency corrected to 1,836 keV was applied to the energy zone affected by the efficiency of 500 keV and the relative error of the measured and corrected values was well matcched by the 3.2 % peak efficiency correction. As with 450 mL CRM source, the larger the volume, the lower the P/T ratio was by ${\pm}5%$. This is due to the increased scattering of gamma-rays emitted as the source becomes farther away from the detector, and this change in P/T has been confirmed to affect the Coincidence summing corrected peak efficiency.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.14 no.4
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• pp.331-341
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• 2016

To evaluate the physicochemical and radiological properties of raw materials and by-products in domestic distribution, about 220 samples with 16 species were prepared. We measured the energy spectrum and the chemical content, such as U, Th, and K, using a $LaBr_3$ scintillation detector and ED-XRF. In addition, HPGe detector was used to analyze the radioac-tivity of $^{234}Th$, $^{234}mPa$, and $^{214}Bi$ in uranium decay series and $^{228}Ac$, $^{212}Pb$, and $^{208}Tl$ in thorium decay series, and $^{40}K$. The correlation between characteristic variables, such as the count rate in several ROIs, chemical content, and radioactivity, was assessed to infer the radioactivity of natural radionuclides through a rapid screening method. Based on the results, a characteristic database for raw material and by-product in domestic distribution was established and it will provide useful information in the analysis procedure and improve the accuracy and reproducibility in the analysis of natural radionuclides.

• Analytical Science and Technology
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• v.13 no.6
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• pp.743-750
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• 2000

For the ${\gamma}$-ray spectrometry analysis of radium and radon in environmental samples, plastic Marinelli beakers have been usually used. But, there are two problems; one is the increment of background by adsorption of airborne radon daughters on the plastic beaker, and other is the incompleteness of radioactive equilibrium by the loss of gaseous radon produced during the radioactive equilibrium process. In order to solve these problems, we made aluminium counting container, and investigated its characteristics. We investigated radioactive equilibrium process using the aluminium container. We found that both solid and liquid samples reached at radioactive equilibrium state in the aluminium container without loss of gaseous radon. By the use of the aluminium container, we established radon and radium analysis method of solid and liquid samples using gamma-ray spectrometry.