Search query: directionally-sensitive radioactive dosimeter

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abstract: In this paper, the authors propose a personal wearable directionally sensitive radiation dosimeter using multiple semiconductor CdZnTe detectors. The proposed dosimeter not only measures the real time dose rate but also provide the direction of the radioactive source. A linear relationship between radioactive source direction and the radiation intensity measured by each detectors is established and an equation to determine the source direction is derived by the authors. The efficiency and accuracy of the proposed dosimeter is verified by simulation using Geant4 package. Results have indicated that in a measurement duration of about 7 seconds, the proposed dosimeter was able to estimate the direction of a 10mCi 137 55Cs radioactive source to within 2 degrees. Keywords Dose rate, Geant4 package, radiation detectors, radioactive source direction.
author_names: Hai H Le

Paul Junor

Moshi Geso

Graeme J O'Keefe
title: Directionally Sensitive Personal Wearable Radiation Dosimeter
year: 2017

abstract: Imaging technology based on gamma ray sources has been extensively used in non destructive testing (NDT) to detect any possible internal defects in products without changing their shapes or functions. However, such technology has been subject to increasingly stricter regulations, and an international radiation safety management system has been recently established. Consequently, radiation source location in NDT systems has become an essential process, given that it can prevent radiation accidents. In this study, we focused on developing a monitoring system that can detect, in real time, the position of a radioactive source in the source guide tube of a projector. We fabricated a lead iodide (PbI2) dosimeter based on the particle in binder method, which has a high production yield and facilitates thickness and shape adjustment. Using a gamma ray source, we then tested the reproducibility, linearity of the dosimeter response, and the dosimeter's percentage interval distance (PID) It was found that the fabricated PbI2 dosimeter yields highly accurate, reproducible, and linear dose measurements. The PID analysis conducted to investigate the possibility of developing a monitoring system based on the proposed dosimeter indicated that the valid detection distance was approximately 11.3 cm. The results of this study are expected to contribute to the development of an easily usable radiation monitoring system capable of significantly reducing the risk of radiation accidents.
author_names: Jin Hyok Kim

Moo-Jae Han

Ye-Ji Heo

Sung-Kwang Park
title: Characterization of a new dosimeter for the development of a position sensitive detector of radioactive sources in industrial NDT equipment
year: 2018

abstract: Fields that use non destructive testing (NDT) invest significant amounts of time and resources toward building a radioactive source monitoring system, for preventing any potential radiation related accidents. However, various elements that can cause potential radiation accidents due to silicon based photodiodes are involved. Therefore, research on new materials that can effectively detect high energy gamma ray is necessary. This study focused on developing a new dosimeter material for a real time monitoring system that can detect the location of a radioactive source. It was confirmed that the fabricated HgI2 dosimeters have sufficient reproducibility and dose linearity for gamma rays. Based on these results, the HgI2 dosimeter was verified to satisfy the general requirements of NDT source monitoring systems. These monitoring systems are expected to be easily operable by workers and prevent potential radiation accidents.
author_names: Kyo-Tae Kim

Joo Hee Kim

Moo-Jae Han

Soon Sung Lee

Ye-Ji Heo

Gyu-Seok Cho

B I Min

Heunglae Cho

Kum-Bae Kim

Sung-Kwang Park
title: Characterization of a HgI2 Dosimeter for the Monitoring System of Position Detection of Radioactive Sources in Gamma Ray Projector
year: 2020

abstract: Recently, cancer has been treated using high dose rates (HDRs) which requires highly reliable treatment plans. In current clinical practice, phosphors are widely used. However, these are of limited use for real time verification of radiation during HDR brachytherapy; moreover, there is a possibility of electrical error via high energy radiation because a photodiode is used to detect visible light. Therefore, it is necessary to develop a new dosimeter that can detect gamma rays effectively. This study aimed to investigate the feasibility of a lead monoxide (PbO) based dosimeter to detect the position of a radioactive source in HDR brachytherapy. It was confirmed that the fabricated PbO dosimeter has sufficient response coincidence, reproducibility, and dose linearity for gamma rays. Based on these results, it is demonstrated that the PbO dosimeter complies with the general requirements of HDR brachytherapy monitoring systems. Thus, the PbO dosimeter is expected to be used commercially in the future.
author_names: Kyoungwoon Kim

Junghyun Kim

Yohan Shin

Moo-Jae Han

Ji-Eun Park

Young Jin Heo

D -H Lee

Heunglae Cho

B I Min

Y -K Oh

Sung-Kwang Park
title: Feasibility study of a lead monoxide based dosimeter for real time radioactive source detection in HDR brachytherapy
venue: Journal of Instrumentation
year: 2019

abstract: Radiation safety management is being considered very important since radioactive isotopes such as Co 60 and Ir 192 are widely used in fields such as non destructive test(NDT) In this study, the applicability of Mercury(II) Iodide(HgI2) source for tracing system was evaluated. To make sure the unit cell sensor's reliability, we evaluated the electrical properties of the sensor made with HgI2, and then position dependence of the sensor was analyzed and compared with the dose distribution from the planning system. As a result of the evaluation, high reliability of the sensor was shown through the linearity of R sq 0.990 and reproducibility of CV 0.015. In the position dependence evaluation, the maximum value was measured at the isocenter of the sensor and gradually decreased according to the distance. However, the dose distribution data from the planning system was turned out that has difference with that of the sensor up to 30% This seems to come from the difference between single point measuring based planning system and area measuring based sensor.
author_names: Yohan Shin

Kyo-Tae Kim

Heunglae Cho

Park Sung-Kwang
title: The Study on Applicability of Semi conductive Compound for Radioactive Source Tracing Dosimeter in NDT Field
year: 2019

abstract: An optical fiber sensor for monitoring low dose radiation is presented. The sensor, based on radiation sensitive scintillation material, terbium doped gadolinium oxysulphide (Gd2O2S:Tb) is embedded in a cavity of 700um diameter within a 1mm plastic optical fiber. The sensor is compared with the treatment planning system for repeatability, angular dependency, distance and accumulated radiation activity. The sensor demonstrates a high sensitivity of 152 photon counts/Gy with a temporal resolution of 0.1 seconds, with the largest repeatability error of 4.1% to 0.361mCi of Iodine 125 the radioactive source most commonly used in LDR brachytherapy for treating prostate cancer.
author_names: Peter Woulfe

Frank Sullivan

Wern Kam

Sinead O'Keeffe
title: Optical fiber dosimeter for real time in vivo dose monitoring during LDR brachytherapy.
venue: Biomedical optics express
year: 2020

abstract: In the decommissioning of the nuclear power plant, especially, for decontamination by radioactive substances caused by 2011 Fukushima nuclear power plant accident has affected the reconstruction after the earthquake, the dose evaluation and validation of the decontamination effect is very important. In order to prepare a novel passive type dosimeter system which can applied to radiation dose monitoring and visualization of two dimensional distribution of ionizing radiation in contaminated area, we try to develop a beads type and a sheet type glass dosimeter utilizing radio photo luminescence (RPL) phenomenon in Ag+ doped phosphate glass. It is confirmed that the beads type glass dosimeter with a diameter of about 50mm exhibits an intense RPL. It is found that the sheet type glass dosimeter which is made of the beads type glasses is useful for monitoring of radiation dose in wide dose range and visualization of dose distribution, for radioactive emergency monitoring.
author_names: Hidehito Nanto

K Hirasawa

Yoshinori Takei

Yuka Yanagida

Masanori Sugiyama

Yoshihiro Koguchi

T Yamamoto

T Hda
title: Monitoring of radiation dose distribution utilizing RPL in glass dosimeter Its application to radioactive emergency sensing
venue: 2017 IEEE SENSORS
year: 2017

abstract: In this chapter, a new radiation sensitive FET (RADFET) dosimeter design (called the Dual Dielectric Gate All Around DDGAA RADFET dosimeter) to improve the radiation sensitivity performance and its analytical analysis have been proposed, investigated and expected to improve the sensitivity behavior and fabrication process for RADFET dosimeter based applications. Analytical models have been developed to predict and compare the performance of the proposed design and conventional (bulk) RADFET, where the comparison of device architectures shows that the proposed design exhibits a superior performance with respect to the conventional RADFET in term of fabrication process and sensitivity performances. The proposed design has linear radiation sensitivities of approximately (95.45\\upmu \mathrm{{V/Gy} for wide irradiation dose range (from \mathrm{{Dose}=50\\mathrm{{Gy} to \mathrm{{Dose}=3000\\mathrm{{Gy} Our results showed that the analytical analysis is in close agreement with the 2 D numerical simulation over a wide range of devices parameters. The proposed device and the Artificial Neural Networks (ANNs) have been used to study and show the impact of the proposed dosimeter on the environment monitoring and remote sensing applications. The obtained results make the DDGAA RADFET dosimeter a promising candidate for environment monitoring applications.
author_names: Faycal Djeffal

M Meguellati
title: Multigate RADFET Dosimeter for Radioactive Environment Monitoring Applications
year: 2013

abstract: Abstract In this paper, a radiation sensitive FET (RADFET) dosimeter design (called the Dual Dielectric Gate All Around DDGAA RADFET dosimeter) to improve the radiation sensitivity performance and its analytical analysis have been proposed for RADFET dosimeter based applications (monitoring, robotics, medical sciences, The proposed device and the Artificial Neural Networks (ANNs) have been used to study and show the impact of the proposed dosimeter on the environment monitoring and remote sensing applications. The obtained results make the DDGAA RADFET dosimeter a promising candidate for environment monitoring applications.
author_names: M Meguellati

Faycal Djeffal

Djemai Arar

Fouzi Douak

L Khettache
title: New RADFET Dosimeter Design For Radioactive Environment Monitoring Applications
year: 2012

abstract: Abstract A radiophotoluminescence (RPL) monitoring scope system was constructed to evaluate radioactive cesium contamination. RPL glass sheets were constructed by bonding RPL glass beads to a backing sheet. The RPL scope was constructed using an image intensifier and a CCD camera to detect RPL from the RPL glass sheet. A UV floodlight was also prepared as an excitation light source. The UV floodlight and an image intensifier were pulse operated for high signal to noise RPL detection. In experiments, the RPL of X ray irradiated glass sheets was measured with this present system. The RPL intensity, which is calculated from the brightness of obtained images, exhibits acceptable linearity to the absorbed dose. Another experiment showed that RPL can be detected at a distance of 10 m between the RPL glass sheets and the RPL detector.
author_names: Naoki Zushi

Fuminobu Sato

Yushi Kato

Takayoshi Yamamoto

Toshiyuki Iida
title: A radioactive contamination monitoring system with a bead type radiophotoluminescence glass dosimeter
year: 2016