Fast-neutron measurement with organic scintillators has been considered one of the alternative te... more Fast-neutron measurement with organic scintillators has been considered one of the alternative techniques to thermal neutron measurement based on He-3 proportional counters, due to their economic and measurement-uncertainty potential for nuclear material accountancy. Nevertheless, highly suppressed neutron detection efficiencies and nuclide-dependent features indicated in the fast system as well as the utilization of pulse-shape discrimination which necessitates a significant energy threshold could lead to challenges in terms of characterizing nuclear material samples. This work confirmed a reasonable similarity of simulated results to experimental results concerning the non-linear light-output function of proton recoils. Consequently, nuclide-dependent detector responses and measurement uncertainty were investigated with varying diverse measurement parameters (the number of detectors, measurement time, and sample quantity). Also, comparative studies were conducted for the ACP Safeg...
In most cases, a PET system has numerous electrical components and channel circuits and thus it w... more In most cases, a PET system has numerous electrical components and channel circuits and thus it would rather be a bulky product. Also, most existing systems receive analog signals from detectors which make them vulnerable to signal distortions. For these reasons, channel reduction techniques are important. In this work, an ASIC for PET module is being proposed. An ASIC chip for 16 PET detector channels, VSSPDC, has been designed and simulated. The main function of the chip is 16-to-1 channel reduction, i.e., finding the position of only the valid signals, signal timing, and magnitudes in all 16 channels at every recorded event. The ASIC comprises four of 4-channel modules and a 2nd 4-to-1 router. A single channel module comprises a transimpedance amplifier for the silicon photomultipliers, dual comparators with high and low level references, and a logic circuitry. While the high level reference was used to test the validity of the signal, the low level reference was used for the timing. The 1-channel module of the ASIC produced an energy pulse by time-over-threshold method and it also produced a time pulse with a fixed delayed time. Since the ASIC chip outputs only a few digital pulses and does not require an external clock, it has an advantage over noise properties. The cadence simulation showed the good performance of the chip as designed.
During the last decade, digital X-ray imaging systems have been replacing analog X-ray imaging sy... more During the last decade, digital X-ray imaging systems have been replacing analog X-ray imaging systems of conventional X-ray film-screen combination for radiography applications. Indirect detection methods consisted of an X-ray converter (or a scintillator film) and photodiode arrays are more widely used in medical diagnoses and industrial fields. Two major scintillation materials such as terbium doped gadolinium oxysulfide (Gd2O2S:Tb, GOS)
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2009
We have manufactured thallium-doped cesium iodide (CsI:Tl) scintillator thin films by the thermal... more We have manufactured thallium-doped cesium iodide (CsI:Tl) scintillator thin films by the thermal deposition method. The scintillation characteristics of the CsI:Tl thin films were studied by X-ray-induced luminescence for different Tl doping concentrations between 0.05 and 1.0 ...
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2009
... Bo Kyung Cha a , Jun Hyung Bae a , Chae-hun Lee a , Hosang Jeon a , Hyunduk Kim a , Sungho Ch... more ... Bo Kyung Cha a , Jun Hyung Bae a , Chae-hun Lee a , Hosang Jeon a , Hyunduk Kim a , Sungho Chang a , Bo-Sun Kang b and Gyuseong Cho a , Corresponding Author Contact Information , E-mail The Corresponding Author. ...
The gamma scintillation camera systems are recently used in various industrial, environmental and... more The gamma scintillation camera systems are recently used in various industrial, environmental and medical diagnostic fields. Moreover, the portable use in various fields is possible using miniaturized gamma camera systems. The necessity of objective and quantitative factors for the performance evaluation of gamma camera systems increase as the usefulness of these systems increase. The detective quantum efficiency(DQE), which is already
Fast-neutron measurement with organic scintillators has been considered one of the alternative te... more Fast-neutron measurement with organic scintillators has been considered one of the alternative techniques to thermal neutron measurement based on He-3 proportional counters, due to their economic and measurement-uncertainty potential for nuclear material accountancy. Nevertheless, highly suppressed neutron detection efficiencies and nuclide-dependent features indicated in the fast system as well as the utilization of pulse-shape discrimination which necessitates a significant energy threshold could lead to challenges in terms of characterizing nuclear material samples. This work confirmed a reasonable similarity of simulated results to experimental results concerning the non-linear light-output function of proton recoils. Consequently, nuclide-dependent detector responses and measurement uncertainty were investigated with varying diverse measurement parameters (the number of detectors, measurement time, and sample quantity). Also, comparative studies were conducted for the ACP Safeg...
In most cases, a PET system has numerous electrical components and channel circuits and thus it w... more In most cases, a PET system has numerous electrical components and channel circuits and thus it would rather be a bulky product. Also, most existing systems receive analog signals from detectors which make them vulnerable to signal distortions. For these reasons, channel reduction techniques are important. In this work, an ASIC for PET module is being proposed. An ASIC chip for 16 PET detector channels, VSSPDC, has been designed and simulated. The main function of the chip is 16-to-1 channel reduction, i.e., finding the position of only the valid signals, signal timing, and magnitudes in all 16 channels at every recorded event. The ASIC comprises four of 4-channel modules and a 2nd 4-to-1 router. A single channel module comprises a transimpedance amplifier for the silicon photomultipliers, dual comparators with high and low level references, and a logic circuitry. While the high level reference was used to test the validity of the signal, the low level reference was used for the timing. The 1-channel module of the ASIC produced an energy pulse by time-over-threshold method and it also produced a time pulse with a fixed delayed time. Since the ASIC chip outputs only a few digital pulses and does not require an external clock, it has an advantage over noise properties. The cadence simulation showed the good performance of the chip as designed.
During the last decade, digital X-ray imaging systems have been replacing analog X-ray imaging sy... more During the last decade, digital X-ray imaging systems have been replacing analog X-ray imaging systems of conventional X-ray film-screen combination for radiography applications. Indirect detection methods consisted of an X-ray converter (or a scintillator film) and photodiode arrays are more widely used in medical diagnoses and industrial fields. Two major scintillation materials such as terbium doped gadolinium oxysulfide (Gd2O2S:Tb, GOS)
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2009
We have manufactured thallium-doped cesium iodide (CsI:Tl) scintillator thin films by the thermal... more We have manufactured thallium-doped cesium iodide (CsI:Tl) scintillator thin films by the thermal deposition method. The scintillation characteristics of the CsI:Tl thin films were studied by X-ray-induced luminescence for different Tl doping concentrations between 0.05 and 1.0 ...
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2009
... Bo Kyung Cha a , Jun Hyung Bae a , Chae-hun Lee a , Hosang Jeon a , Hyunduk Kim a , Sungho Ch... more ... Bo Kyung Cha a , Jun Hyung Bae a , Chae-hun Lee a , Hosang Jeon a , Hyunduk Kim a , Sungho Chang a , Bo-Sun Kang b and Gyuseong Cho a , Corresponding Author Contact Information , E-mail The Corresponding Author. ...
The gamma scintillation camera systems are recently used in various industrial, environmental and... more The gamma scintillation camera systems are recently used in various industrial, environmental and medical diagnostic fields. Moreover, the portable use in various fields is possible using miniaturized gamma camera systems. The necessity of objective and quantitative factors for the performance evaluation of gamma camera systems increase as the usefulness of these systems increase. The detective quantum efficiency(DQE), which is already
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