체렌코프 복사와 광전자 증배관을 이용한 뮤온검출기 제작 및 납에 의한 뮤온 차폐 효과 연구

오하영,우재현,이해원 한국물리학회 2018 새물리 Vol.68 No.5

Cherenkov radiation originating from charged particles moving fast in water can be detected by using photoelectron multiplier tubes. Using this fact and apparatuses easily obtained from the Physics Department, we were able to build a muon detector for educational purposes. With this detector, we tried to detect muons reaching Earth's surface from above. The kinetic energy of the muons decreases as they move in lead materials. Using the detector, we investigated how the number of muon signals varies with the shield thickness and the ways of placing the lead shields. 빠른 전하입자가 물 속을 통과할 때 발생하는 체렌코프 광을 광전자증배관(photoelectron multiplier tube, PMT)으로 검출할 수 있다. 이 현상을 이용하여 비싼 기기 대신 물리학과에서 어렵지 않게 구할 수 있는 기기 만으로 교육용으로 사용할 수 있는 뮤온검출기를 자작(do-it-yourself, DIY)하였다. 또한 이 뮤온 검출기를 사용하여 대기에서 발생하여 지상에 도달하는 뮤온을 간접적으로 확인하고자 하였다. 뮤온은 밀도가 높은 물질인 납(lead)을 통과할 때 운동에너지가 감소하는 것으로 알려져 있다. 따라서 검출기를 이용하여 납 차폐체의 두께와 배치 방향에 따른 뮤온 신호의 변화를 알아보는 실험을 하였다. 이 실험을 통해 납 두께가 두꺼워지면 신호가 감소하고 배치방향에 따라서도 신호가 달라지는 것을 확인하였다.

실리콘 광증배소자로 이루어진 차세대 광센서의 디자인 및 시뮬레이션

이혜영,전진아,이직,박일흥,김석환,양슬기 한국물리학회 2012 새물리 Vol.62 No.12

The silicon photomultiplier (SiPM) is an extremely sensitive detector with the capability for single-photon counting as with a Photomultiplier tube (PMT). A photosensor consisting of multiple arrays of SiPMs can be used as an image sensor that can detect ultrafast objects in the environment of the old (dark) moon with the special properties of a high sensitivity and a time resolution of a few nanoseconds. Also, the features of the SiPMs provide a promising photon sensor for various applications that require low power,compactness, insensitiveness to even very strong magnetic fields,mechanical robustness, resistance to damage from accidental and prolonged light exposure, etc.We have designed an array of 8× 8 SiPMs on one silicon substrate, each pixel consisting of 10^3 photodiode micropixels. The out dimension of the array is 5mm × 5 mm. We have a plan for making a 6400 pixel image sensor with the arrays. In this paper, the design scheme and a simulation of the performance are presented. 광전자증배소자(Silicon Photomultiplier, SiPM)는 기존의광전증배관(Photomultiplier tube)과 같이 단일광자까지 측정할 수 있는초민감한 반도체 광센서이다. SiPM은 초민감성과 함께 수나노의 초고속반응 특성을 갖고 있어 야간에 이미지확보는 물론, 초고속으로 움직이는물체를 인식할 수 있는 이미지 센서로 사용될 수 있다. 또한 SiPM은소형, 저중량, 저전력, 기계 견고성 등 여러 특성을 가지고 있어 다양한응용분야에 적용될 수 있다. 우리는 SiPM을 대화소 이미지 센서로 만들기위해 8 × 8 SiPM 배열을 설계했다. 각 SiPM은 10^3의마이크로픽셀로 구성되어 있으며, 8 × 8 SiPM 배열의 크기는 대략5 × 5 mm^2 이다. 우리는 이 SiPM배열을 사용하여 차후 6,400픽셀 이미지 센서를 개발하고자 한다. 본 논문에서는 제작에 앞서 센서의설계 및 애벌런치 방전을 발생시키는 시뮬레이션 조건에 관하여연구하였다.

Characterization of a 20-inch Micro Channel Plate Photomultiplier Tube

Geonwoo Kim,Jik Lee,Hongjoo Kim 한국물리학회 2022 새물리 Vol.72 No.6

There is a proposal to construct a large neutrino detector in Korea, called Korean Neutrino Observatory (KNO), which consists of a large water tank and several tens of thousands of photosensors placed deep underground for neutrino detection. A 20-inch-diameter photosensor including a microchannel plate-photomultiplier Tube (MCP-PMT) is a candidate for the KNO due to its large photo-coverage. We characterized a 20-inch MCP-PMT by measuring its properties, including single photoelectron charge resolution, gain, signal-to-noise performance, dark count rate, after-pulse ratio, and timing performance. We present our measurements of its properties and compare them with those of a previous study.<br/>

Scanning Spontaneous Photon Emission From Transplanted Ovarian Tumor of Mice Using a Photomultiplier Tube

Kim, Jungdae,Lim, Jaekwan,Kim, Hongbae,Ahn, Saeyoung,Sim, Sung-Bo,Soh, Kwang-Sup Taylor Francis 2006 Electromagnetic biology and medicine Vol.25 No.2

<P>A scanning system for the detection of spontaneous ultraweak photon emission from nude mice with transplanted tumors is presented. A photomultiplier tube (PMT) with an effective area of 15 mm diameter was used for measuring photon emission in a wavelength range from 300 to 650 nm. Tumors were induced in nude mice by transplantation of an ovarian cancer cell line into the back of mice. The PMT was moved for scanning over the whole body of a mouse placed in a dark box. The profiles of the intensities of photon emissions from the tumor mice are presented and compared with those obtained from the control mice.</P>

중성미자 검출기에서 광증폭관들의 작동 상태에 따른 재구성된 이벤트 위치 정보의 분해능 변화 연구

서준후,조햅 아티프,신창동,주경광,박영서 한국물리학회 2019 새물리 Vol.69 No.9

질량이 거의 없고 물질과의 상호작용을 잘 하지 않아 검출이 어려웠던 중성미자에 대한 연구가 최근에활발히 이루어지고 있고, 중성미자에 대한 물리적인 성질들이 밝혀지고 있다. 중성미자를 검출하기 위한검출기의 종류는 다양하지만, 신호 검출을 위해 일반적으로 광증폭관이 사용된다. 광증폭관들로부터측정된 신호정보를 통해 입사된 중성미자의 위치 정보를 재구성할 수 있다. 그러나 시간이 지남에 따라광증폭관들의 성능과 작동효율 등이 변하여 광증폭관들의 개수가 초기 상태와 비교해 줄어들면 재구성된중성미자 위치 정보에 영향을 주게 된다. 이 논문에서는 원자로 중성미자와 원통형 액체섬광검출기를 기반으로 설계한 몬테카를로 시뮬레이션 기법을 활용하여 광증폭관들의 작동 상태에 따라 재구성된 중성미자의위치 정보의 분해능 변화를 알아보았다. The properties of neutrinos are not well known because they are weakly interacting with surrounding matter. Recently, studies on neutrinos have been actively conducted, and several results and interesting phenomena have been obtained. Various types of detectors for detecting neutrinos are used, but photomultiplier tubes (PMTs) are more generally used. In particular, a signal generated in each PMTs is used to reconstruct the position information of the neutrino incident on the detector. However, if the number of PMTs is decreased from the initial value, the performance of the PMTs and the operation efficiency may change over time, which may affect the information on the reconstructed position of the incident neutrino. This, in turn, has a direct impact on the results that utilize the reconstructed vertex information. This paper describes in brief the dependence of the resolution of the reconstructed vertex on the operating status of the PMT in the reactor neutrino detector. The Monte Carlo simulation technique was designed based on the cylindrical liquid-scintillating-detector model.

First Test of the CTOF@CLAS12 Detector Counter with Proton Beams

니안드레이,V. Kuznetsov,S. Chebotarev,H. Dho,A. Kim,김우영,E. Milman,M. Lee,T. Yang 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.59 No.23

CTOF@CLAS12 plastic scintillator counter was tested with proton beam at Korea Institute of Radiological and Medical Sciences (KIRAMS). The counter have been designed and constructed as a plastic scintillation bar coupled with the 1.5 and the 2 inches of diameter fine mesh photomultiplier tubes (FM-PMTs). The dependence of the TOF resolution on the light output has dened. Obtained results of the 1.5'', 2'' FM-PMTs' timing and gain performances in magnetic eld confirm their suitability for precise particle identification in the CLAS12 future detector.

NaI ( T1 ) 섬광결정과 위치민감형 광전자증배관을 이용한 유방암 진단용 소형 감마카메라 개발

김종호,최용,권홍성,김희중,김상은,최연성,이경한,김문회,주관식,김병태 ( Jong Ho Kim,Yong Choi,Hong Seong Kwon,Hee Joung Kim,Sang Eun Kim,Yearn Seong Choe,Kyung Han Lee,Moon Hae Kim,Koan Sik Joo,Byung Tae Kim ) 대한핵의학회 1998 핵의학 분자영상 Vol.32 No.4

Purpose: The conventional gamma camera is not ideal for scintimammography because of its large detector size ( 500 mm in width) causing high cost and low image quality. We are developing a small gamma camera dedicated for breast imaging. Materils and Methods: The small gamma camera system consists of a NaI (Tl) crystal (60 mm X60 mm X6 mm) coupled with a Hamamatsu R3941 Position Sensitive Photomultiplier Tube (PSPMT), a resister chain circuit, preamplifiers, nuclear instrument modules, an analog to digital converter and a personal computer for control and display. The PSPMT was read out using a standard resistive charge division which multiplexes the 34 cross wire anode channels into 4 signals (X, X, Y, Y ). Those signals were individually amplified by four preamplifers and then, shaped and amplified by amplifiers. The signals were discriminated and digitized via triggering signal and used to localize the position of an event by applying the Anger logic. Results: The intrinsic sensitivity of the system was approximately 8,000 counts/.'ec/pCi. High quality flood and hole mask images were obtained. Breast phantom containing 2-7 mm diameter spheres was successfully imaged with a parallel hole collimator. The image displayed accurate size and activity distribution over the imaging field of view. Conclusion: We have succesfully developed a small gamma camera using NaI(T1)-PSPMT and nuclear instrument modules. The small gamma camera developed in this study might imprnve the diagnostic accuracy of scintimammography by optimally imaging the breast. (Korean J Nucl Med 1998;32:365-73)

에어로졸 라이다의 편광 모듈 파라메터에 관한 연구

장재경,이주희,박찬봉 慶熙大學校 레이저 工學硏究所 1999 레이저공학 Vol.10 No.-

We study on Parameter of depolarization module of the aerosol lidar system to measure depolarization ratio. Nd:YAG solid state laser with second, third harmonic generator (1064 nm: 280 mJ, 532 nm: 157 mJ, 355 nm: 142 mJ), cassegrain type telescope (60 cm), optical part and electronic unit. comprises Aerosol lidar system. In this paper we examine optimum telescope Fov and PMT dynamic range, then measured aerosol depolarization ratio at altitude range of 2~7 Km.

Feasibility of in situ measurements for the monitoring of strontium-90 in the River and Dam

Hye Min Park,Jeong Ho Kim,Sung Won Kang,Koan Sik Joo 대한방사선방어학회 2017 대한방사선방어학회 학술발표회 논문요약집 Vol.2017 No.11

Resistive network를 이용한 단순화된 의료영상 검출 방법

전수진,박창인,손병희,정미,김태룡,지명기,최영완 한국정보통신설비학회 2015 한국정보통신설비학회 학술대회 Vol.2015 No.08