• Nuclear Engineering and Technology
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• v.28 no.4
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• pp.397-404
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• 1996

The hydrogenated amorphous silicon (a-Si : H) holds good promise for radiation detection from its inherent merits over crystalline counterpart. For the application to alpha spectroscopy, the induced charge collection in a-Si : H pin detector diodes ons simulated based on a relevant non-uniform charge generation model. The simulation was peformed for the initial energy and the range of incident alpha particles, detector thickness and the operational parameters such as the applied reverse bias voltage and shaping time. From the simulation, the total charge collection was strongly affected by hole collection as expected. To get a reasonable signal generation, therefore, the hole collection should be seriously considered for detector operational parameters such as shaping time and reverse voltage etc. For the spectroscopy of alpha particle from common alpha sources, the amorphous silicon should have about 70${\mu}{\textrm}{m}$ thickness.

• Nuclear Engineering and Technology
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• v.4 no.3
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• pp.223-228
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• 1972

In the radiography, of thick materials the scattered rays from an object are one of major causes to reduce the quality of the radiographic image on the film. To determine the rate of scattering of incident gamma rays by an objective specimen, film blacknesses are measured for various slit widths. For each measurement, the changes of a penetrameter's sensitivity are also evaluated. It is observed that the fault-detectability can be improved by reducing the slit width when the fault detectability deteriorates due to the increase in scattered gamma rays by thicker samples. This experiment has been carried out with the iron specimens and $^{60}$ Co source.

• Advances in materials Research
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• v.4 no.1
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• pp.23-30
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• 2015

Energy absorption and exposure buildup factor have been computed for natural uranium in the energy range of 0.05-15MeV up to penetration depth of 40 mfp. Five-parameter geometric progression (G-P) fitting method has been used to compute buildup factors of uranium. The variation of energy absorption and exposure buildup factors with, penetration depth and incident photon energies for the uranium has been studied. It has been concluded that the values of energy absorption and exposure buildup factors are very large at 0.15 MeV.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.05a
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• pp.925-930
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• 1995

A new approach on the correction for Compton escape component in X-ray unfolding algorithm was investigated to obtain more accurate X-ray source spectrum. The X-ray detector used in this study was a planar type HPGe detector(EG&G ORTEC, GLP-32340/13-P-LP) whose energy response has been blown and ISO narrow beam series were employed as source spectrum. At lower energy Part of measured X-ray spectrum including the correction for Compton escape component more accurate unfolded spectrum was obtained by letting down the starting energy level of the collection in existing spectrum correction procedure to consider multiple scattering effects. It is, from this study, concluded that accurate correction for Compton escape component is needed in X-ray unfolding procedure since Compton scattering becomes more important as incident X-ray energies increase.

• Nuclear Engineering and Technology
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• v.49 no.8
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• pp.1758-1771
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• 2017

In this study, to determine the most effective alloy for shielding against gamma-rays, the gamma-ray shielding parameters of six types of cerrobend alloys have been investigated. Gamma-ray interaction with the cerrobend alloys has been discussed mainly in terms of total mass attenuation coefficient (${\mu}_t$), half value layer (HVL), tenth value layer (TVL), effective atomic number ($Z_{eff}$), and effective electron density ($N_{eff}$). These parameters have been calculated by theoretical approach using the ParShield program in a photon energy range between 0.1 MeV and 100 GeV. The dependence of these parameters on the incident photon energy and chemical composition of the cerrobend alloys has been studied.

• Nuclear Engineering and Technology
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• v.32 no.5
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• pp.457-464
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• 2000

In this paper, we describe the results of various calculations performed for a design of the thickness gauges that use the gamma-ray backscattering method. The radiation source is assumed to be the $_{24}$1Am(60keV gamma-ray) and the detector is a single crystal scintillator in a cylindrical form. The source is located at the center of the detector with the collimator of a cylindrical shape. First, when gamma-rays are incident on a material with a constant angle, we compute the variations of the spectrum for the photons scattered into different angular intervals. Next, we compute for an optimal size for the collimator cylinder for a fixed detector size and an optimal distance from the detector to the material. Finally, we compute the number of observed photons for different thickness of two different materials, a plastic film and an Al foil.

• Nuclear Engineering and Technology
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• v.50 no.5
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• pp.751-757
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• 2018

In this article, a UV sensor that is an appropriate tool for fire detection has been designed and constructed. The structure of this UV sensor is an air-filled single-wire detector that is able to operate under normal air condition. A reflective CsI photocathode is installed at the end of the sensor chamber to generate photoelectrons in the ion chamber. An electric current is produced by accelerating photoelectrons to the anode in the electric field. The detector is able to measure the intensity of the incident UV rays whenever the current is sufficiently high. Therefore, the sensitivity coefficient of this sensor is found to be $7.67{\times}10^{-6}V/photons/sec$.

• Nuclear Engineering and Technology
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• v.34 no.1
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• pp.22-29
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• 2002

The angular correlation effect was investigated for Co-60 ${\gamma}$-ray spectroscopy by using HPGe detector and the effective angular correlation was theoretically calculated by considering the finite detector solid angle. For the calculation of effective angular correlation, the detection efficiency as a function of ${\gamma}$-ray incident direction was obtained by using Monte Carlo method and the first interaction model. The results and the methods used in the calculation are discussed.

• Nuclear Engineering and Technology
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• v.53 no.12
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• pp.4080-4092
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• 2021

In this study, the performance of sequence tracking methods for multiple interaction events in specific CdZnTe Compton imagers was evaluated using Monte Carlo simulations. The Compton imager consisted of a 6 × 6 array of virtual Frisch-grid CZT crystals, where the dimensions of each crystal were 5 × 5 × 12 mm³. The sequence tracking methods for another Compton imager that consists of two identical CZT crystals arrays were also evaluated. When 662 keV radiation was incident on the detectors, the percentages of the correct sequences determined by the simple comparison and deterministic methods for two sequential interactions were identical (~80%), while those evaluated using the minimum squared difference method (55-59%) and Three Compton method (45-55%) for three sequential interactions, differed from each other. The reconstructed images of a 662 keV point source detected using single and double arrays were evaluated based on their angular resolution and signal-to-noise ratio, and the results showed that the double arrays outperformed single arrays.

• Nuclear Engineering and Technology
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• v.51 no.1
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• pp.170-175
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• 2019

Displacement cross-sections for an advanced assessment of radiation damage rates were obtained for a number of materials using the arc-dpa model at neutron incident energies from $10^{-5}eV$ to 10 GeV. Evaluated data files, CEM03 and ECIS codes, and an approximate approach were applied for the calculation of recoil energy distributions in neutron induced reactions. Three sets of displacement cross-sections based on the use of low-energy data from JEFF-3.3, ENDF/B-VIII.0, and JENDL-4.0u were prepared. Files contain also cross-sections calculated using the standard NRT model. Special efforts were made to estimate the uncertainty of obtained displacement cross-sections.