In this work, we investigate the potential of exploiting TiO2 thin films as sensing layers on silicon micro-electromechanical systems for the detection of gamma radiations. All samples are exposed to gamma rays produced by 60Co, with different doses ranging from 0 kGy to 40 kGy. Properties of silicon coated with a 200-nm-thick layer of TiO2 grown at 200 °C by atomic layer deposition are studied before and after its gamma irradiation using x-ray diffraction (XRD), scanning electron microscopy, and spectroscopic ellipsometry. Atomic force microscopy (AFM) is carried out on functionalized microcantilevers to measure the resonance frequency shift (Δf 0) resulting from irradiation of the TiO2 thin film. XRD results show a change in the films from a mixture of rutile and anatase phases to an anatase phase upon irradiation. Spectroscopic ellipsometry results show a change with a fixed pattern in the film thickness, roughness, void, and optical constants with different irradiation doses. This pattern appears as Δf 0 in AFM, where the response of sensors to doses between 0 kGy and 20 kGy was linear. The values of Δf 0 are convenient to control parameters for the proposed dosimeter, which is characterized by the reproducibility and sensitivity of measurements. The maximum detectable linear effect of the proposed dosimeter was found at a dose of 20 kGy. This makes a 200-nm thin layer of TiO2 coated on a microcantilever surface, a possible candidate for dosimetry for the range lower than 20 kGy applications, such as in personal dosimeters.

Exploiting the properties of TiO2 thin films as a sensing layer on (MEMS)-based sensors for radiation dosimetry applications

We study a resource-constrained project scheduling problem in a hazardous environment considering some different strategies of staffing. An overhaul project of a nuclear power plant is chosen as a ...

https://www.tandfonline.com/doi/pdf/10.1080/21642583.2018.1494638

Research on a resource-constrained project scheduling problem in a hazardous environment and its staffing strategies based on PSO algorithm

Reinvestigations of the Li2O–Al2O3 system. Part I: LiAlO2 and Li3AlO3

An aluminate is a compound containing an oxyanion of aluminum. Many aluminates are found in nature. A large number of phosphors that are used in various applications, such as scintillation detectors, optical thermometry, long‐lasting phosphorescence, solid‐state lighting, solid‐state lasers, upconversion, bioimaging, and plasma display panels, are based on aluminate formulae. This review focuses on the synthesis and characteristics of such phosphors. The conventional as well as novel methods of synthesizing these phosphors are reviewed. The emphasis on commercially important aluminate phosphors is discussed.

Luminescent Materials Based on Aluminates: A Review

Thermo-gravimetric kinetics analysis for the synthesis of lithium aluminate and fabrication of pebbles by solid state reaction process

Synthesis of lithium aluminate for application in radiation dosimetry

Based on guides RG 1.109, RG 1.111 published by United States Nuclear Regulatory Commission (USNRC), our research concentrates in assessing radiation doses caused by radioactive substances released from the nuclear power plant (NPP) Ninh Thuan 1 under the scenario of normal operation using software package NRCDose72 provided by the USNRC. The database including the released radioactive nuclides, meteorology, terrain, population and agricultural production activities have been collected and processed to build the input data for the model calculation. The wind rose distribution obtained from the meteorological data in a five-year period from 2009-2013 showed that the radioactive nuclides released to environment spread in two main wind directions which are North East and South West. The X/Q (s/m3) and D/Q (s/m2) qualities which are, respectively, the ratio of activity concentration to release rate and that of deposition density of radioactive nuclides to release rate were calculated within an area of 80 km radius from the NPP site using XOQDOQ. Population doses were calculated using GASPAR. The XOQDOQ and GASPAR are two specific softwares in NRCDose72 package.

/pdf/assessment-of-radiation-dose-caused-by-radioactive-gaseous-3hwaebvs7v.pdf

Assessment of Radiation Dose Caused by Radioactive Gaseous Effluent Released from Nuclear Power Plant Ninh Thuan 1 under Scenario of Normal Working Conditions

Major aim of the paper is to determine calibration factor for LR 115 type II detectors used to measure indoor 220Rn . To determine calibration factor, LR 115 detectors were fixed on top and bottom inside urban cup chamber and sent to NIRS, Japan to 220Rn calibration exposure. After detectors have been calibration exposure at NIRS, authors carried out following all steps of procedure, which set up at laboratory in INST, Vietnam. This paper discusses the experimental method that is used in calculating the calibration factor of 220Rn inside the urban cup, calibration factors (CF) were determined by experimental with detectors placed at top and bottom inside urban cup were 0.023 ± 0.004 and 0.038 ± 0.007(tracks.cm-2/Bq.m-3.d), respectively. The curve between integrated 220Rn concentration and tracks density with factor R2=0.96 and 0.97 at top and bottom inside urban cup, respectively. In order to precision evaluation, authors used 20 couple of LR-115 detectors at 8cm detector-source distance with relative standard deviation less than 1.48%.

Calibration Factor for LR 115 Type II Detectors Used to Measure Indoor 220 Rn

Based on guides RG 1.109, RG 1.111 published by United States Nuclear Regulatory Commission (USNRC)~our~research~concentrates on assessing radiation doses caused by radioactive substances released from the nuclear power plant (NPP) Ninh Thuan 1 to the environment under scenario of an INES-level 5 nuclear accident caused by two incidents of the station black out (SBO) and loss of coolant accident (LOCA) using software~RASCAL4.3~provided by the Emergency Operations Center of USNRC. The plant Ninh Thuan 1 is assumed to use the VVER-1200 technology with a total power of 2400 MW\(_{e}\). The input data for the model calculations is based on building the accident scenario, the technical parameters of VVER-1200 technology and the meteorology. The meteorological data on dry and rainy seasons, which are typical for the Ninh Thuan region was also considered. The \(X/Q\) (s/m\(^{3}\)) quality and the maximum dose values were calculated within an area of 40 km radius from the NPP site, where \(X/Q\) (s/m\(^{3}\)) is the ratio of activity concentration to release rate. Based on the obtained results on dose distribution the necessary measures for nuclear emergency preparedness have been proposed according to the IAEA recommendations.

/pdf/assessment-of-radioactive-gaseous-effluent-released-from-5e3yto2y3c.pdf

Trinh Van Giap

Papers

Synthesis of lithium aluminate for application in radiation dosimetry

Assessment of Radiation Dose Caused by Radioactive Gaseous Effluent Released from Nuclear Power Plant Ninh Thuan 1 under Scenario of Normal Working Conditions

Calibration Factor for LR 115 Type II Detectors Used to Measure Indoor 220 Rn

Assessment of Radioactive Gaseous Effluent Released From Nuclear Power Plant Ninh Thuan 1 under Scenario of Ines-Level 5 Nuclear Accident