• Journal of the Korean Society of Radiology
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• v.8 no.6
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• pp.287-292
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• 2014

In this study, the neutron capture cross section of $^{180}Ta$(natural existence ratio: 0.012 %) obtain by measuring has been compared with the evaluated data for the capture data. In generally, the neutron capture resonance is defined as Breit-Wigner formula. The formula consists of the resonance parameters such as neutron width, total width and neutron width. However in the case of $^{180}Ta$, these are very poor experimental neutron capture cross section data and resonance information in below 10 eV. Therefore, in the study, we analyzed the neutron resonance of $^{180}Ta$ with the measuring the prompt gamma-ray from the sample. And the resonance was compared with the evaluated data by Mughabghab, ENDF/B-VII, JEFF-3.1 and TENDL 2012. Neutron sources from photonuclear reaction with 46-MeV electron linear accelerator at Research Reactor Institute, Kyoto University used for cross section measurement of $^{180}Ta(n,{\gamma})^{181}Ta$ reaction. $BGO(Bi_4Ge_3O_{12})$ scintillation detectors used for measurement of the prompt gamma ray from the $^{180}Ta(n,{\gamma})^{181}Ta$ reaction. The BGO spectrometer was composed geometrically as total energy absorption detector.

• Journal of the Korean Society of Radiology
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• v.6 no.5
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• pp.403-408
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• 2012

Prompt gamma ray from the natural Indium sample was measured by using an assembly of BGO($Bi_4Ge_3O_{12}$) scintillation detectors in the neutron energy region from 1 to 300 eV. The assembly was composed of pieces of BGO. The spectrometer was composed geometrically as total energy absorption detector. 46-MeV electron linear accelerator which is located at Research Reactor Institute, Kyoto University used for neutron sources from photonuclear reaction. The measurement of the neutron capture resonances was performed to below neutron energy 1 keV, because of strong X-ray effect from photonuclear reaction in Ta target and short distance from the target to an assembly of detector. The distance of neutron flight path is $12.7{\pm}0.02m$. The large neutron capture resonances were measured from 1 to 400 eV. The energy in the capture resonance was compared with the evaluated values. The large resonances were seen in the present measurement. General agreement can be seen between the present measurement and the previous evaluated data in relevant energy region. In the present study, we measured the continues resonance structure above 1 keV neutron energy region. 91.49 eV new neutron capture resonance was found in present measurement.

• Nuclear Engineering and Technology
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• v.35 no.4
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• pp.347-355
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• 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 Microbiology and Biotechnology
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• v.28 no.9
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• pp.1433-1442
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• 2018

To identify and quantify the effects of a combination of dietary $1{\times}10^8CFU/g$ Lactococcus lactis subsp. lactis I2 ($LI_2$) and 0.1% ${\beta}$-glucooligosaccharides (BGO) on the growth and immunity of olive flounder (Paralichthys olivaceus), a feeding experiment was conducted. Flounder ($14{\pm}0.5g$) were divided into two groups and fed control and synbiotic feeds for 8 weeks. Investigations were carried out on growth and feed utilization, innate immunity, serum biochemical parameters, intestinal lactic acid bacterial (LAB) viability, microvillus length, and changes in the expression levels of genes encoding pro-inflammatory cytokines (tumor necrosis factor $[TNF]-{\alpha}$, interleukin $[IL]-1{\beta}$, and IL-6). Results demonstrated the synbiotic diet had significantly better (p < 0.05) responses in terms of weight gain and specific growth rate, three innate immune parameters (respiratory burst, serum lysozyme, and superoxide dismutase), intestinal LAB viability, and the relative $TNF-{\alpha}$ expression level (p < 0.05). Moreover, after challenge with Streptococcus iniae ($1{\times}10^8CFU/ml$), the synbiotically fed group exhibited significantly higher (p < 0.05) protection against streptococcosis, validating the observed changes in immune parameters and induction of the cytokine-encoding gene. Therefore, according to the results of the present study, synbiotic feed ($LI_2+BGO$) increased growth, modulated innate immune parameters and protected olive flounder against streptococcosis.

• Journal of the Korean Society for Nondestructive Testing
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• v.22 no.5
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• pp.474-482
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• 2002

One dimensional Radiometric scanning system was fabricated and tested as a filmless radiographic inspection system, which could be applied to the evaluation of the corrosion and deposits in the pipeline. This system is composed of the single radioactive source of the collimated focusing beam, and single scintillation detector of BGO, and the mechanical scanning system to transport and align the source and detector, and the operating software to automatically control the mechanical scan system. The performance of the system was simulated using GEANT4 software. This system is applied to one specimen having an artificial falw(flat bottom hole) in the pipe and the other specimen with thickness variation. For the inspection by using the radioactive source in the pipeline, it is possible to evaluate the corrosion and deposits in real time and without film.

• Journal of the Korean Society for Nondestructive Testing
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• v.22 no.5
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• pp.500-507
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• 2002

By this study, on-line real-time radiometric system was developed using a 64 channels linear array of solid state detectors to measure wall thickness of insulated piping system. This system uses an Ir-192 as a gamma ray source and detector is composed of BGO scintillator and photodiode. Ir-192 gamma ray source and linear detector array mounted on a computer controlled robotic crawler. The Ir-192 gamma ray source is located on one side of the piping components and the detector array on the other side. The individual detectors of the detector array measure the intensity of the gamma rays after passing through the walls and the insulation of the piping component under measurement. The output of the detector array is amplified by amplifier and transmitted to the computer through cable. This system collects and analyses the data from the detector array in real-time as the crawler travels over the piping system. The maximum measurable length of pipe is 120cm/min. in the case of 1mm scanning interval.

• The Korean Journal of Nuclear Medicine
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• v.38 no.4
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• pp.318-324
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• 2004

Purpose: Philips GEMINI is a newly introduced whole-body GSO PET/CT scanner. In this study, performance of the scanner including spatial resolution, sensitivity, scatter fraction, noise equivalent count ratio (NECR) was measured utilizing NEMA NU2-2001 standard protocol and compared with performance of LSO, BGO crystal scanner. Methods: GEMINI is composed of the Philips ALLEGRO PET and MX8000 D multi-slice CT scanners. The PET scanner has 28 detector segments which have an array of 29 by 22 GSO crystals ($4{\times}6{\times}20$ mm), covering axial FOV of 18 cm. PET data to measure spatial resolution, sensitivity, scatter fraction, and NECR were acquired in 3D mode according to the NEMA NU2 protocols (coincidence window: 8 ns, energy window: $409[\sim}664$ keV). For the measurement of spatial resolution, images were reconstructed with FBP using ramp filter and an iterative reconstruction algorithm, 3D RAMLA. Data for sensitivity measurement were acquired using NEMA sensitivity phantom filled with F-18 solution and surrounded by $1{\sim}5$ aluminum sleeves after we confirmed that dead time loss did not exceed 1%. To measure NECR and scatter fraction, 1110 MBq of F-18 solution was injected into a NEMA scatter phantom with a length of 70 cm and dynamic scan with 20-min frame duration was acquired for 7 half-lives. Oblique sinograms were collapsed into transaxial slices using single slice rebinning method, and true to background (scatter+random) ratio for each slice and frame was estimated. Scatter fraction was determined by averaging the true to background ratio of last 3 frames in which the dead time loss was below 1%. Results: Transverse and axial resolutions at 1cm radius were (1) 5.3 and 6.5 mm (FBP), (2) 5.1 and 5.9 mm (3D RAMLA). Transverse radial, transverse tangential, and axial resolution at 10 cm were (1) 5.7, 5.7, and 7.0 mm (FBP), (2) 5.4, 5.4, and 6.4 mm (3D RAMLA). Attenuation free values of sensitivity were 3,620 counts/sec/MBq at the center of transaxial FOV and 4,324 counts/sec/MBq at 10 cm offset from the center. Scatter fraction was 40.6%, and peak true count rate and NECR were 88.9 kcps @ 12.9 kBq/mL and 34.3 kcps @ 8.84 kBq/mL. These characteristics are better than that of ECAT EXACT PET scanner with BGO crystal. Conclusion: The results of this field test demonstrate high resolution, sensitivity and count rate performance of the 3D PET/CT scanner with GSO crystal. The data provided here will be useful for the comparative study with other 3D PET/CT scanners using BGO or LSO crystals.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.12
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• pp.1894-1899
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• 1990

We present an electro-optical voltage sensor. Crystalline bismuth germanate(BI4Ge3O12) used as the electro-opticla crystal exhibited linear birefringences of 1.7x10**-5 to 5.4x10**-4. And these birefringences were observed to be strongly temperature dependent. In order to improve the stability of the electro-opticlal voltage sensor, crystals (Bi4Ge3=12) were annealed and a compensation method was used. After applying this compensation method to the voltage sensor, the temperature stability, pressure stability, and vibration stability of the sensor were highly improved, Noise Equivalent Voltage of this sensor was a few mV/\ulcornerz.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1750-1752
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• 2001

본 논문에서는 전기광학효과를 이용한 전압 계측기기의 개발을 위해 수행한 기초 연구에 대하여 기술하였다. 측정 시스템에 사용된 소자의 특성 및 입출력 특성에서 약 800 V까지의 출력특성이 측정오차 3% 내의 선형성을 나타내었으며, $\lambda$/4 Plate를 사용한 경우, 측정 정확도를 높일 수 있음을 확인하였다. 본 실험에서는 DKDP를 포켈스 소자로 사용하였으나, BGO와 같은 결정을 사용하면 수십 kV까지의 높은 전압을 직접 측정하는 것도 가능하다.

• Journal of the Korean Society of Radiology
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• v.1 no.2
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• pp.31-35
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• 2007

Energy calibration is important to identify accurate neutron capture resonance energy in the neutron TOF (Time-of-Flight) experiment. In present study, the accurate neutron capture resonance energies of natural Sm were measured by using a 46-MeV electron linear accelerator (linac) at the Research Reactor Institute, Kyoto University(KURRI). The BGO spectrometer were adopted for measurement the prompt capture gamma-ray of the sample. To obtain energy calibration curve, resonance energy of a gold sample used as standard resonance energy Mughabghab's data (From neutron resonance parameters data). Previous data (by Mughabghab) of natural Sm sample have been compared with the present result.