Thermoluminescence energy response of TLD-100 subjected to photon irradiation using Monte Carlo N-particle transport code version 5

Useful TL properties of TLD-100 that is an excellent candidate for using in TL dosimetry of ionizing radiation are demonstrated. This study is focused on response of TLD-100 subjected to photon irradiation. The thermoluminescence (TL) response of TLD-100 subject to various photon energy, ranging from 20 keV to 6 MeV, was investigated as energy absorbed in the TL material using Monte Carlo N-Particle transport code version 5 (MCNP5). The input parameters included in this study are experimental geometry specification, source information, material information, and tallies. Tally F6 is used in this simulation. The results from MCNP5 simulation show good agreement with previous experimental data. However, the data obtained from the simulation are greater than the experimental data especially in lower energy ranges

The thermoluminescence response of doped SiO2 optical fibres subjected to fast neutrons

This paper describes a preliminary study of the thermoluminescence (TL) response of doped SiO2 optical fibres subjected to 241AmBe neutron irradiation. The TL materials, which comprise Al- and Ge-doped silica fibres, were exposed in close contact with the 241AmBe source to obtain fast neutron interactions through use of measurements obtained with and without a Cd filter (the filter being made to entirely enclose the fibres). The neutron irradiations were performed for exposure times of 1-, 2-, 3-, 5- and 7-days in a neutron tank filled with water. In this study, use was also made of the Monte Carlo N-particle (MCNPTM) code version 5 (V5) to simulate the neutron irradiations experiment. It was found that the commercially available Ge-doped and Al-doped optical fibres show a linear dose response subjected to fast neutrons from 241AmBe source up to seven days of irradiations. The simulation performed using MCNP5 also exhibits a similar pattern, albeit differing in sensitivity. The TL response of Ge-doped fibre is markedly greater than that of the Al-doped fibre, the total absorption cross section for Ge in both the fast and thermal neutrons region being some ten times greater than that of Al

Correlation between gross alpha and beta activity concentration in soil samples with dose rates in Iskandar Malaysia, Johor, Malaysia

The objective of this study was to determine the gross alpha and gross beta activity concentrations in soil samples collected in Iskandar Malaysia, Johor, Malaysia. A total of 32 soil samples were collected and the dose rates at the location were measured 1 m above the ground. The gross alpha activity concentration ranged from 140 to 2,010 Bq kg-1 with the mean value of 796 ± 70 Bq kg-1. The gross beta activity ranged from 40 to 2,300 Bq kg-1 with the mean value of 837 ± 30 Bq kg-1. The results of analysis show strong correlation between gross alpha activity concentration and dose rate (R = 0.90) and gross beta activity concentration and dose rate (R = 0.84)

Assessment of natural radionuclides at Kinta River, Malaysia: relationship between the turbidity to uranium and thorium concentrations

This study aims to investigate the relationship between the turbidity to uranium and thorium concentrations. Since the radionuclides analysis is complex and time consuming, turbidity monitoring on river is proposed to be an indirect indicator for uranium and thorium concentration. Eighteen water samples were collected and turbidity measurements were conducted at several locations from Kinta River. The concentration of uranium and thorium were analyzed using inducted coupled plasma mass spectrometer (ICP-MS). The concentrations of thorium were varied from 44 ng L?1 to 787 ng L?1 while the concentration of uranium varied from 45 ng L?1 to 371 ng L?1. Statistical analyses were applied to determine the relation between turbidity and concentrations of uranium and thorium at Kinta River. The correlation coefficients (R) show a strongly correlation, with R values of 0.915 and 0.881 for turbidity with concentrations of uranium and thorium, respectively

Thermoluminescence energy response of TLD-100 subjected to photon irradiation using Monte Carlo N-particle transport code version 5

Useful TL properties of TLD-100 that is an excellent candidate for using in TL dosimetry of ionizing radiation are demonstrated. This study is focused on response of TLD-100 subjected to photon irradiation. The thermoluminescence (TL) response of TLD-100 subject to various photon energy, ranging from 20 keV to 6 MeV, was investigated as energy absorbed in the TL material using Monte Carlo N-Particle transport code version 5 (MCNP5). The input parameters included in this study are experimental geometry specification, source information, material information, and tallies. Tally F6 is used in this simulation. The results from MCNP5 simulation show good agreement with previous experimental data. However, the data obtained from the simulation are greater than the experimental data especially in lower energy ranges

Thermoluminescence energy response of a germanium-doped optical fiber obtained using a Monte Carlo N-particle code simulation

This paper reports on the energy response of a Ge-doped optical fiber subjected to photon irradiation. The thermoluminescence (TL) responses of the Ge-doped optical fiber for various photon energies ranging from 20 keV to 6 MeV were investigated as energy absorbed in the TL material by using the Monte Carlo N Particle transport code version 5 (MCNP5). The results obtained are compared against results for the thermoluminescence dosimeter 100 (TLD-100). The input parameters included in this study were the geometry specification, the source information, the material information and tallies. Tally F6 is an important parameter in data card which was used in this simulation as a energy-dependant heating function instead of flux. Similar patterns of response were found for each dosimeter. The simulation shows that the optical fiber has a greater response than TLD 100 in the lower energy range, but the responses overlap in the higher energy ranges

Site selection for nuclear power plant in Mersing Johor

Nuclear power is considered as energy source option for future power generation in the National New Energy Policy 2010. The first nuclear power plant (NPP) construction is expected to start at 2017, and officially operated in 2025. This paper aims to propose possible candidate site areas for NPP in Mersing District, Johor. The evaluation uses the Atomic Energy Licensing Board (AELB) guideline documents as main reference, supported by regulation documents from International Atomic Energy Agency (IAEA). 4 safety parameters are used in the assessment – geological characteristic, air dispersion (meteorological) analysis, population data and safety characteristics. This study ranked 4 proposed areas possible candidate site area for NPP in Mersing district

Thermoluminescence energy response of germanium doped optical fibre using Monte Carlo N-particle code simulation

Over the last decade, the investigation of thermoluminescence (TL) dosimetry has expanded enormously. Many phosphor materials have been studied, become commercially available and have been applied to many areas of ionizing radiation dosimetry. This study is focusing on energy response of commercially available silicon dioxide optical fibre subjected to photon irradiation. The result obtained will be compared with energy response of TLD 100. The TL response of various photon energy, ranging from 20 keV to 6 MeV, was investigated as energy absorbed in the TL material. The study was carried out using Monte Carlo N‐Particle transport code version 5 (MCNP5). The inputs parameters include in this study are geometry specification, source information, material information and tallies. Tally F6 is use in this simulation. Even though the same pattern of response can be seen from each material, the simulation shows that the fibre optic had a greater response than TLD 100 in the lower energy ranges but slightly lower response than TLD 100 in the higher energy ranges

Determination of surface radiation dose-rate in the environment of Kelantan State, Malaysia

Measurements of environmental surface radiation dose rate in Kelantan state, Malaysia was carried out using a portable hand held radiation survey meter and Global Positioning System (GPS). The surface radiation dose rates ranged from 44 to 500 nGy h-1. The measurements were done based on geology and soil types of the area. The mean radiation dose rate was found to be 209 ± 8 nGy h-1. Few areas of relatively enhanced activity were located in Pasir Mas, Tanah Merah and Jeli districts which have external gamma dose rates between 300 to 500 nGy h_1. An Isodose map of the state was produced using ArcGIS10 software version 10.1. To evaluate the radiological hazard due to terrestrial gamma dose, the annual effective dose equivalent (AEDE), the mean population weighted dose rate and cancer risk factor were calculated and found to be relative excess lifetime cancer risks were 1.280 mSv y-1, 18 mSv and 1.04×10-3 respectively

Thermoluminescence responses of photon- and electron-irradiated lithium potassium borate co-doped with Cu+Mg or Ti+Mg

New glasses Li2CO3–K2CO3–H3BO3 (LKB) co-doped with CuO and MgO, or with TiO2 and MgO, were synthesized by the chemical quenching technique. The thermoluminescence (TL) responses of LKB:Cu,Mg and LKB:Ti,Mg irradiated with 6 MV photons or 6 MeV electrons were compared in the dose range 0.5–4.0 Gy. The standard commercial dosimeter LiF:Mg,Ti (TLD-100) was used to calibrate the TL reader and as a reference in comparison of the TL properties of the new materials. The dependence of the responses of the new materials on 60Co dose is linear in the range of 1–1000 Gy. The TL yields of both of the co-doped glasses and TLD-100 are greater for electron irradiation than for photon irradiation. The TL sensitivity of LKB:Ti,Mg is 1.3 times higher than the sensitivity of LKB:Cu,Mg and 12 times less than the sensitivity of TLD-100. The new TL dosimetric materials have low effective atomic numbers, good linearity of the dose responses, excellent signal reproducibility, and a simple glow curve structure. This combination of properties makes them suitable for radiation dosimetry