• Title/Summary/Keyword: Gamma-ray source

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Packing effects on the intracavitary radiation therapy of the utaine lervix cancer ($^{192}Ir$source를 이용할 자궁경부암 강내치료시 사용하는 packing의 효과에 대한 고찰)

  • Cho, Jung-Kun;Lee, Du-Hyun;Si, Chang-Kun;Choi, Yoon-Kyung;Kim, Tae-Yoon
    • The Journal of Korean Society for Radiation Therapy
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    • v.16 no.1
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    • pp.73-77
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    • 2004
  • Purpose of the radio-therapy is maximize the radiation dose to the tumor while minimizing the dose to the critical organ. Carcinoma of the uterine cervix treatment are external irradiation or an interstitial brachtheraphy make use of isotope. Brachytherapy is a method of radiotherapy in advantage to achieve better local control with minimum radiation toxicity in comparison with external irradiation because radiation dose is distributed according to the inverse square low of gamma-ray emitted from the implanted sources. Authors make use of the patients data which 192Ir gives medical treatment intrcavity. Intracavitary radiation of the uterine cervix cancer, critical organ take $20\%$ below than exposure dose of A point in the ICRU report. None the less of the advice, Radiation proctitis and radiation cystitis are frequent and problematic early complications in patients treated with radiation for the uterine cervix cancer. In brachytherapy of uterine cervical cancer using a high dose rate remote afterloading system, it is of prime importance to deliver a accurate dose in each fractionated treatment by minimizing the difference between the pre-treatment planned and post-treatment calculated doses. Use of packing to reduce late complications intracavitary radiation of the uterine cervix cancer. Bladder and rectum changes exposure dose rate by radiotherphy make use of packing.

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Preliminary Study on Electron Paramagnetic Resonance(EPR) Signal Properties of Mobile Phone Components for Dose Estimation in Radiation Accident (방사선사고시 피폭선량평가를 위한 휴대전화 부품의 전자상자성공명(EPR) 특성에 대한 예비 연구)

  • Park, Byeong Ryong;Ha, Wi-Ho;Park, Sunhoo;Lee, Jin Kyeong;Lee, Seung-Sook
    • Journal of Radiation Protection and Research
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    • v.40 no.4
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    • pp.194-201
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    • 2015
  • We have investigated the EPR signal properties in 12 components of two mobile phones (LCD, OLED) using electron paramagnetic resonance (EPR) spectrometer in this study.EPR measurements were performed at normal atmospheric conditions using Bruker EXEXSYS-II E500 spectrometer with X-band bridge, and samples were irradiated by $^{137}Cs$ gamma-ray source. To identify the presence of radiation-induced signal (RIS), the EPR spectra of each sample were measured unirradiated and irradiated at 50 Gy. Then, dose-response curve and signal intensity variating by time after irradiation were measured. As a result, the signal intensity increased after irradiation in all samples except the USIM plastic and IC chip. Among the samples, cover glass(CG), lens, light guide plate(LGP) and diffusion sheet have shown fine linearity ($R^2$ > 0.99). Especially, the LGP had ideal characteristics for dosimetry because there were no signal in 0 Gy and high rate of increase in RIS. However, this sample showed weakness in fading. Signal intensity of LGP and Diffusion Sheet decreased by 50% within 72 hours after irradiation, while signals of Cover Glass and Lens were stably preserved during the short period of time. In order to apply rapidly EPR dosimetry using mobile phone components in large-scale radiation accidents, further studies on signal differences for same components of the different mobile phone, fading, pretreatment of samples and processing of background signal are needed. However, it will be possible to do dosimetry by dose-additive method or comparative method using unirradiated same product in small-scale accident.

Studies on the Applications of PSL, TL and ESR Methods for the Detection of Dried Fruits and Mushrooms (PSL, TL 및 ESR 분석에 의한 건조과일류 및 버섯류에 대한 검지 특성 연구)

  • Kim, Kyu-Heon;Son, Jin-Hyok;Kang, Yoon-Jung;Park, Hye-Young;Hwang, Cho-Rong;Kim, Jae-I;Lee, Kang-Bong;Jo, Tae-Yong;Eom, Mi-Ok;Park, Sue-Nie;Seong, Rack Seon;Jang, Young-Mi;Lee, Jae-Hwang;Park, Yong-Chjun;Lee, Hwa-Jung;Lee, Sang-Jae;Han, Sang-Bae
    • Journal of Radiation Industry
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    • v.7 no.1
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    • pp.7-14
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    • 2013
  • In this study, we investigated the applicability of the photostimulated luminescence (PSL), thermoluminescence (TL) and electron spin resonance (ESR) methods for various foods. The analysed samples consist of 11 items including dried fruits (6 items) and mushrooms (5 items). To compare between non-irradiated and irradiated food, all samples were irradiated with $^{60}Co$ gamma-ray source. In PSL study, the photon counts of all the unirradiated sample were identified negative (lower than 700). The photon counts irradiated (1, 5, 10 kGy) dried date-palm, dried jujube and mushrooms (Auricularia auricula, Phellinus linteus and Sarcodon aspratus) showed positive (higher than 5,000) and the results for the other samples were negative or intermediate (>700 and >5,000). In TL analysis most of items can be applicable to detect irradiated foods because of showing TL ratio above 0.1. The glow curves by TL method were estimated in the range of $150{\sim}250^{\circ}C$ in irradiated samples. In ESR measurements, the intensity of ESR signal (single-line) increased as the dose of irradiation increased. In particular, the specific ESR signals of irradiation-induced radical were detected in dried papaya, dried date-palm, dried banana, dried pineapple and S. aspratus. According to the results, PSL, TL and ESR methods were successfully applied to detect the irradiated foods. It is concluded that PSL, TL and ESR methods are suitable for detection of irradiated samples and a combined method is recommendable for enhancing the reliability of detection results.