• The Korean Journal of Malacology
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• v.27 no.3
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• pp.247-252
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• 2011

The effect of ${\gamma}$-ray irradiation on the color of nucleus and cultured pearls was investigated. After ($^{60}Co$) ${\gamma}$-ray irradiation on the pearl nucleus, its color was altered from brownish to blackish brown or gray depending on irradiation dose. It was clearly found that the all samples are composed of aragonite. ESR spectra were based on the measurement of the paramagnetic species $CO_2$-radicals by the interaction with the ${\gamma}$-ray irradiation in $Mn^{2+}$ containing $CaCO_3$. In this study, we investigated optimal detection method of ${\gamma}$-ray irradiation to establish destructive or non-destructive test for pearl nucleus.

• Journal of Radiation Protection and Research
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• v.16 no.2
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• pp.7-16
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• 1991

Measurement of Co-60 gamma rays has been made for establishment of exposure standard and analyze it's overall uncertainties. Exposure rate determined by the charge mode method using vibrating reed amplifier with cylinderical type cavity chamber. The values of a variety of physical constants and the correction factors are evaluated. The resulting exposure rate is 690.81 R/h at the distance of 1m from the source and the related uncertainties is ${\pm}0.8%$

• Nuclear Engineering and Technology
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• v.14 no.2
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• pp.64-69
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• 1982

Directional correlation measurements for the Co-60 and Cs-134 cascade gamma-rays have been performed in the angular range from 90$^{\circ}$ to 180$^{\circ}$ by use of the fast coincidence scintillation spectrometer incorporated with a gamma-ray polarimeter based on the Compton scattering effect to determine the polarization correlations. The experimental method together with the theoretical background is described, and the results are shown graphically to represent the consistency of the measurement with approximate theoretical estimates.

• The Journal of Korean Society for Radiation Therapy
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• v.4 no.1
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• pp.12-16
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• 1990

• The Journal of the Korean dental association
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• v.9 no.10
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• pp.585-591
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• 1971

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.4
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• pp.193-200
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• 2014

In this paper, the prototype of one-channel gamma-ray spectroscope for automatic radiopharmaceutical systhesis system was designed and characterized. The prototype employed CZT (CdZnTe) spear detector for gamma-ray detection and employed analog-type signal processing method. A radioactive sample Co-60 was used for measuring performance of the gamma-ray spectroscope and energy spectrum is gained with bandwidth of 1173keV. The analog board is made up of SF (shaping filter) and PHA (peak and hold amplifier) for shaping CZT output signal appropriately and ADC (analog to digital converter) and FPGA (field programmable gate array) for drawing gamma-ray spectrum by counting the digitalized gamma-ray signal data.

• Nuclear Engineering and Technology
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• v.5 no.2
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• pp.83-86
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• 1973

The protective effects of acetylbenzoylaconine, 2-aminoethylisothiouronium bromide hydrobromide, $\beta$-mercaptoethylamine HCI, and L-thiazolidine-4-carboxylic acid were studied on the white male mice, aged 5-6 weeks. The toxicity test of acetylbenzoylaconine revealed that the LD$_{50}$ was 2.5 mg/kg of body weight. After the administration of test substances, mice were irradiated with whole body dose of 800 rad by the Co-60 source. Observing the number of surviving mice for 30 days, the survival coefficients for the test groups were calculated and with these the protective coefficients against radiation injury, PCR, were also calculated. The PCR values are 2.24, 2.95, 2.78, and 1.23 for acetylbenzoylaconine, 2-aminoethylisothiouronium bromide hydrobromiide, $\beta$-mercaptoethylamine HCI, and L-thiazolidine-4-carboxylic acid respectively. These values reveal that the acetylbenzoylaconine has protective potency against radiation injury on white male mice.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2004.11a
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• pp.149-152
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• 2004

물 흡수선량 표준에 토대를 두고 있는 프로토콜에서는 저에너지 전자선의 경우 평행평판형이온함의 사용과 기준 선질 $^{60}$CO 감마선의 물 흡수선량 교정정수를 받은 원통형이온함을 사용하여 고에너지 전자선에서 평행평판형이온함을 교차교정하도록 권고하고 있다. 따라서 본 연구에서는 국제원자력기구의 프로토콜(IAEA TRS-398)에서 권고하고 있는 절차에 따라 저에너지 전자선에 대한 원통형이온함의 선질보정정수를 계산하고, 원통형이온함과 평행평판형이온함의 교정방법에 따른 흡수선량을 상호 비교하였다. 그 결과 전자선에너지 10 MeV 이상에서는 두 이온함간의 선량이 잘 일치하였으나 전자선에너지 6, 9 MeV에서 최대 3.3%까지 선량 차이를 보여 저에너지 전자선에서는 반드시 평형판판형이온함의 사용하여 선량측정 할 것을 권고한다. 교정방법 차이에 의한 평행평판형이온함의 선량은 서로 잘 일치하는 것으로 나타나 표준기관에서 직접 교정받은 $^{60}$Co 감마선의 물 흡수선량교정정수를 사용하여 전자선 물 흡수선량을 결정해도 큰 영향은 없을 듯하다. 또한 평행평판형이온함을 교차 교정하기 위한 전자선 에너지에 따른 흡수선량을 상호 비교한 결과 20MeV이외 12, 16 MeV의 전자선 에너지에서도 잘 일치하여 교차교정을 위한 전자선의 기준 선질에 대한 연구가 더 진행되어야 한다고 사료된다.

• Journal of Radiation Protection and Research
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• v.9 no.1
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• pp.11-18
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• 1984

A Standard gamma-ray ionization chamber system was developed with a well type ionization chamber and micro current measuring circuit. Micro current was measured by the automatic Townsend balance with stepwise compensation method. For gamma emitting nuclides such as $^{241}Am,\;^{133}Ba,\;^{60}Co,\;^{134}Cs,\;^{137}Cs,\;and\;^{22}Na$ relative calibration factors to $^{226}Ra$ reference source were calculated and detection .efficiency curve was determined as a fudnction of gamma energy.

• Journal of Radiation Protection and Research
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• v.11 no.2
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• pp.123-129
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• 1986

Using Cs-137 and Co-60 gamma-ray irradiation systems, the buildup factors for 2.9 cm thick lead absorber and the air scattering factors are determined for different beam solid angles from$2.4{\pi}{\times}10^{-3}sr\;to\;17.3{\pi}{\times}10^{-3}sr$. The corresponding buildup factors are turned out to be the values from 1.054 to 1.194 and the scattering factors to be the values from 1 to 1.064, respectively. To verify our results, calculated values using these factors and experimental values are compared. The differences between them are not more than 3. 3%.