LiF:Mg,Cu,Na,Si TL 소자의 선량계적 특성

남영미,김장렬,장시영 대한방사선 방어학회 2001 방사선방어학회지 Vol.26 No.1

최근 개발된 방사선량 측정용 LiF:Mg,Cu,Na,Si TL 소자의 글로우 곡선, 방출스펙트럼, 광자에 대한 선량의존성, 에너지의존성 및 페이딩 등과 같은 물리적 및 선량계적 특성들을 연구하였다. LiF:Mg,Cu,Na,Si TL 소자는 LiF:Mg,Cu,Na,Si TL 분말에 압력을 가한 후 소결하는 방법으로 제조되었다. 방사선에 대한 특성을 알아보기 위하여 광자선 조사는 한국원자력연구소의 X선 발생 장치 및 137Cs γ선 원격조사장치를 이용하였으며, 사용된 광자선 에너지 범위는 20-662keV, 선량 범위는 10-6-102 Gy이었다. 글로우 곡선은 수동형의 TLD 판독장치 (System 310, Teledyne)로 질소를 흘리면서 선형적인 가열률로 측정하였으며, TL 강도는 글로우 곡선을 전체 적분한 면적으로 평가하였다. 5℃·s-1의 선형적인 가열률로 측정한 글로우 곡선은 5개의 피그들로 분리되었으며, 234℃에 나타나는 주피크의 활성화에너지는 2.34 eV, 진동수인자는 1.00×1023이고, 방출스펙트럼은 410nm를 중심으로한 단일한 분포로 나타났다. 선량의존성은 100Gy 이상까지 선형성을 나타내었으며, 137Cs에 대한 저에너지 광자의 상대적인 에너지 반응값은 20% 범위 이내였다. 또한 실온에서 1년간 보관하였을 때, 시간경과에 따른 TL 감도의 감소가 거의 없는 좋은 페이딩 특성을 보였다. Sintered LiF:Mg,Cu,Na,Si thermoluminescence (TL) pellets were developed for application in radiation dosimetry. In the present study, the TL dosimetric properties of LiF:Mg,Cu,Na,Si TL pellets have been investigated for emission spectrum, dose response, energy response, and fading characteristics. LiF:Mg,Cu,Na,Si TL pellets were made by using a sintering process, that is, pressing and heat treatment from TL powders. Photon irradiations for the experiments were carried out using X-ray beams and a 137Cs gamma source at the Korea Atomic Energy Research Institute(KAERI). The average energies and the dose were in the range of 20-662 keV and 10-6- 102 Gy, respectively. The glow curves were measured with a manual type TLD reader(System 310, Teledyne) at a constant nitrogen flux and a linear heating rate. For a constant heating rate of 5℃·s-1, the main dosimetric peak of glow curve appeared at 234℃, the activation energy was 2.34eV and frequency factor was 1.00×1023. TL emission spectrum is appeared at the blue region centered at 410 nm. A linearity of photon dose response was maintained up to 100 Gy. The photon energy responses relative to 137Cs response were within ±20% at overall photon energy region. The fading of TL sensitivity of the pellets stored at the room temperature was not found for one year.

개인방사선피폭선량평가

이형섭,김장렬,윤석철,이상윤 대한방사선 방어학회 1994 방사선방어학회지 Vol.19 No.2

최근, 개인방사선피폭선량평가에 관한 기술기준이 과학기술처에 의해 고시됨에 따라 국내에서도 개인선량계를 이용한 체외피폭선량평가결과의 신뢰성 문제가 크게 대두되고 있다. 한국원자력연구소에서는 이러한 구내의 상황을 인식하고 자체적인 신뢰성 확보를 위해 미국의 Oak Ridge국립연구소의 주관하에 개인피폭선량의 평가에 관한 국제상호비교검증시험(Personnel Dosimetry Intercomparison Study ; PDIS) 을 수행하였다. 비교 검증시험에는 한국원자력연구소에서 사용하고 있는 Teledyne PB-3 열형광선량계가 사용되였으며 선량게산 알고리즘은 Teledyne PB-3 version1.5-1989를 사용하였다. 본 연구에서는 지금까지 실시된 PDIS의 결과를 요약하고 현재 PB-3 시스템의 개인선량평가성능에 대해 고찰하였으며, 선량평가절차에 대한 문제점 도출을 통하여 직업적 방사선피폭선량 평가능력의 향상을 위한 방안을 제시하였다. Recently, the Ministry of Science and Technology issued a Ministerial Ordinance (N0 1992-15) about the technical criteria on personnel radiation dosimetry. In today's climate, it is important to demonstrate and document that the processor's systems and services to others meet national standards of quality. The purpose of this study is to verify the performance of the Teledyne PB-3 personnel dosimetry system that is generally used in Korea Atomic Energy Research Institute (KAERI) by intercomparison with Oak Ridge National Laboratory. The KAERI has been participated in this personnel dosimetry intercomparison study(PDIS) program since 1991 and it could be possible to test and calibrate personnel monitoring system. This report presents a summary and analysis of by about 50 does equivalent measurements reported for PDIS-16 through 18 (1991-1993) with emphasis on neutron does equivalent sensitivity, accuracy and methods to improve personnel dosimetry performance are also discussed.

Li 화합물을 첨가한 CaSO₄:Dy 열중성자 측정용 TLD 소자 개발

양정선,김두영,박재우,김장렬,장시영 제주대학교 방사능이용연구소 2003 연구보고 Vol.17 No.-

Personal neutron dosimetry is quite a difficult area because a neutron is always accompanied with gamma radiation, which is required of a capability for mixed field dosimetry. CaSO₄:Dy phosphor is known to have a very high sensitivity to gamma, but the neutron capture cross section of the constituents of CaSO₄:Dy are so small that the interactions between the thermal neutron and the phosphor are rare. One method to improve the neutron interaction is by introducing an impurity ion with a large thermal neutron captures cross section into the phosphor to act as a neutron target centre such as 6Li. In neutron-gamma mixed radiation fields, if two detectors for the 6Li-7Li compounds embedded CaSO₄:Dy TL pellets are used, a 6Li-compound embedded pellet can detect the neutron and gamma radiation together, and the other pellet can only detect the gamma radiation. Recently Korea Atomic Energy Research Institute (KEARI) has developed a new type of CaSO₄:Dy TL materials embedded with phosphorous (KCT-300) to detect beta and gamma radiation with a very high sensitivity[1]. This paper presents the development of CaSO₄:Dy TL pellets embedded with 6Li compound for a thermal neutron measurement, and the detection method of the neutron and gamma dose in mixed fields with CaSO₄:Dy TL pellets embedded with a 6Li compound(KCT-306) and CaSO₄:Dy TL pellets embedded with a 7Li compound(KCT-307) is introduced. The net neutron sensitivity of CaSO₄:Dy TL pellets embedded with 6Li compound developed in this study is higher than that of the TLD-600 (Harshaw Co.) dosimeter which is available in the open market.

Development of Dose Evaluation Algorithm for Film Badge Using ISO Reference Radiations

Jang-Lyul Kim,Si-Young Chang,Jai-Ki Lee 대한방사선방어학회 1995 방사선방어학회지 Vol.20 No.1

Energy and Angular Response of CR-39 Neutron Track Detector

Kim, Jang-Lyul,Ha, Chung-Woo,Yoon, Yea-Chang,W.G. Cross,A. Arneja Korean Nuclear Society 1988 Nuclear Engineering and Technology Vol.20 No.2

중성자 에너지의 함수로써 여러 연구기관들에 의하여 발표된 CR-39검출기의 효율측정은 서로 많은 차이가 있음을 보여주고 있다. 이러한 차이는 부식조건, 방사체의 물질과 두께, 각 회사 제품에 따른 CR-39의 감도 그리고 계수하는 부식직경의 크기 등에 기인된다. 본 논문에서는 계산결과와 함께 에너지 및 각에 따른 분포에 대한 효과들을 검토하였다. 몇가지 에너지에 대해서만 수행된 중성자 입사각에 따른 반응변화의 계산 및 실험결과는 에너지 반응의 결과보다 더욱 일치하는 것을 알 수 있었다. 계산결과에 따르면 입사각에 대한 반응은 약 0.3 MeV 이하를 제외하고는 중성자 에너지에 다라 심하게 변하지 않는다는 것을 보여준다. Published data of the efficiency of CR-39 detectors as a function of neutron energy from different laboratories show wide variations in the response obtained. These variations result from differences in etching conditions, in the materials and thickness of the radiator, in the sensitivities of CR-39 from different manufacturers and perhaps in criteria used for the size of spots that are counted. This paper describes some effects of these factors on the energy and angular response with calculational results. Calculated and measured results of the variations of response with neutron incident angie are more consistent than those of energy response. The data calculated show that the angular response is not a strong function of neutron energy except below about 0.3 MeV.

SPECTRUM WEIGHTED RESPONSES OF SEVERAL DETECTORS IN MIXED FIELDS OF FAST AND THERMAL NEUTRONS

Kim, Sang In,Chang, Insu,Kim, Bong Hwan,Kim, Jang Lyul,Lee, Jung Il Korean Nuclear Society 2014 Nuclear Engineering and Technology Vol.46 No.2

The spectrum weighted responses of various detectors were calculated to provide guidance on the proper selection and use of survey instruments on the basis of their energy response characteristics on the neutron fields. To yield the spectrum weighted response, the detector response functions of 17 neutron-measuring devices were numerically folded with each of the produced calibration neutron spectra through the in-house developed software 'K-SWR'. The detectors' response functions were taken from the IAEA Technical Reports Series No. 403 (TRS-403). The reference neutron fields of 21 kinds with 2 spectra groups with different proportions of thermal and fast neutrons have been produced using neutrons from the $^{241}Am$-Be sources held in a graphite pile, a bare $^{241}Am$-Be source, and a DT neutron generator. Fluence-average energy ($E_{ave}$) varied from 3.8 MeV to 16.9 MeV, and the ambient-dose-equivalent rate [$H^*(10)/h$] varied from 0.99 to 16.5 mSv/h.

Domestic Intercomparison Study for the Performance of Personnel Dosimeters

Jang-Lyul Kim,Si-Young Chang,Bong-Hwan Kim 대한방사선방어학회 1996 방사선방어학회지 Vol.21 No.3

Development of TLD Algorithms by Monochromatic Fluorescence Radiations and Continuous Spectrum X-rays

Jang-Lyul Kim,Bong-Hwan Kim,Si-Young Chang,Jai-Ki Lee 대한방사선방어학회 1998 방사선방어학회지 Vol.23 No.3

Non-L-cell Immunophenotype and Large Tumor Size in Rectal Neuroendocrine Tumors Are Associated With Aggressive Clinical Behavior and Worse Prognosis

Kim, Joo Young,Kim, Ki-Suk,Kim, Kyung-Jo,Park, In Ja,Lee, Jong Lyul,Myung, Seung-Jae,Park, Yangsoon,Park, Young Soo,Yu, Chang Sik,Kim, Jin Cheon,Yu, Eunsil,Jang, Hyeung-Jin,Hong, Seung-Mo Wolters Kluwer Health, Inc. All rights reserved. 2015 The American journal of surgical pathology Vol.39 No.5

According to the 2010 World Health Organization classification, all gastrointestinal neuroendocrine tumors (NETs) are classified as malignant except for L-cell-type (glucagon-like peptide [GLP] and peptide YY [PYY]-producing) NETs. However, L-cell immunophenotype in rectal NETs has not been widely studied previously. Immunohistochemical labeling of L-cell markers with GLP1 and PYY was performed in 208 surgically or endoscopically resected rectal NET cases with tissue microarrays and was compared with clinicopathologic features and patient survival. Rectal NETs with non-L-cell immunophenotype and large tumor size (>1 cm) were associated with increased tumor grading, advanced T category, lymphovascular and perineural invasions, and lymph node and distant metastases (P<0.001, each). Rectal NET patients with non-L-cell phenotype and measuring >1 cm had significantly worse survival outcome than other groups by univariate (P<0.001) and multivariate (P<0.001) analyses. In summary, non-L-cell immunophenotype and large tumor size are associated with increased tumor grading and staging, concurrently indicating that they are independently poor prognostic indicators in rectal NET patients. Therefore, combining L-cell phenotype and tumor size can demonstrate the clinical behavior of rectal NETs more precisely than use of L-cell immunophenotype alone.

Characteristics of CaSO4:Dy TL Dosimeters by Determining LLDs, Fadings and Sensitivity Changes in Repeat Uses

Jang-Lyul Kim,Bong-Hwan Kim,Si-Young Chang,Hyung-Sub Lee,Jae-Ki Lee 대한방사선방어학회 1997 방사선방어학회지 Vol.22 No.3