LR-115 Nuclear Track Detectors Research Articles

Measurement of Radon Concentrations and Annual Dose Rate in some Regions of Baghdad City using LR-115 Nuclear Track Detector

In this work, LR-115 solid state nuclear track detector used to measure the indoor and outdoor radon concentrations, the annual absorbed dose rate and annual effective dose rate to the lung, were measured in nine houses at different places of Baghdad city, the observed values of indoor and outdoor radon concentrations was in range of 14.7-46.17 Bq/m 3 and 9.69–35.69 Bq/m 3 respectively. The resulting concentration of Short-lived radon daughters expressed in term of an equilibriumequivalent radon concentration (EEC), the minimum and maximum indoor results of (EEC) was 5.88-18.46 Bq/m 3 and the outdoor results was 6.78-24.98 Bq/m 3 . The Potential Alpha Energy (PAE) concentration expressed in Working Level (WL) units was in the range of 1.58-4.99 mWL in indoor and 1.8-6.75 mWL in outdoor regions. The annual effective dose calculated according to the radiation weighting (WR) factor for alpha particles and the tissue weighting (WT) factor and the annual absorbed dose rate, the present results confirmed that the radon gas concentrations in all the nine places of Baghdad city are lower than the International Commission Radiation Protection (ICRP) agency, recommended value (200Bq/m 3 ).

Results from time integrated measurements of indoor radon, thoron and their decay product concentrations in schools in the Republic of Macedonia.

As part of a survey on concentrations of radon, thoron and their decay products in different indoor environments of the Balkan region involving international collaboration, measurements were performed in 43 schools from 5 municipalities of the Republic of Macedonia. The time-integrated radon and thoron gas concentrations (CRn and CTn) were measured by CR-39 (placed in chambers with different diffusion barriers), whereas the equilibrium equivalent radon and thoron concentrations (EERC and EETC) were measured using direct radon-thoron progeny sensors consisting of LR-115 nuclear track detectors. The detectors were deployed at a distance of at least 0.5 m from the walls as well as far away from the windows and doors in order to obtain more representative samples of air from the breathing zone; detectors were exposed over a 3-month period (March-May 2012). The geometric mean (GM) values [and geometric standard deviations (GSDs)] of CRn, CTn, EERC and EETC were 76 (1.7), 12 (2.3), 27 (1.4) and 0.75 Bq m(-3) (2.5), respectively. The equilibrium factors between radon and its decay products (FRn) and thoron and its decay products (FTn (>0.5 m)) were evaluated: FRn ranged between 0.10 and 0.84 and FTn (>0.5 m) ranged between 0.003 and 0.998 with GMs (and GSDs) equal to 0.36 (1.7) and 0.07 (3.4), respectively.

Determination the Concentration of the Radon in some Drinking Bottled Water in Baghdad using LR-115 Detector

In the present study ten samples of bottled water from Baghdad conservative were taken to measure the concentration of radon gas by using nuclear track detector LR-115.The result obtained are varying from(0.033)to(0.007)pCi.l-1and these values are very low than the allowed limits (5) pCi.l-1, and specific activity from bottled water has been calculated which was vary from (0.00027)to(0.00126) Bq.l-1 and these values are very low than allowed limits (0.0123) Bq.l-1 that mean the bottled water was treated with good treatment to decrease the side effect of radon

Determination the Concentration of the Radon in some Drinking Bottled Water in Baghdad using LR-115 Detector

In the present study ten samples of bottled water from Baghdad conservative were taken to measure the concentration of radon gas by using nuclear track detector LR-115.The result obtained are varying from(0.033)to(0.007)pCi.l-1and these values are very low than the allowed limits (5) pCi.l-1, and specific activity from bottled water has been calculated which was vary from (0.00027)to(0.00126) Bq.l-1 and these values are very low than allowed limits (0.0123) Bq.l-1 that mean the bottled water was treated with good treatment to decrease the side effect of radon

Study of subsoil radon anomaly using LR-115 (II) nuclear track detectors in and around the Geleki oilfield, Assam Shelf

The subsoil radon gas anomaly in and around the anticlinal structure of the Geleki oilfield, Assam Shelf was studied using LR-115 (II) nuclear track detectors following a grid-sampling pattern. The present study was undertaken to understand the variability of the soil-gas radon concentrations with reference to the oil-wells, drilling activities and local geology. From the alpha-tracks formed on the detectors, the soil-gas radon concentrations were determined using a Spark Counter. The results showed that the natural background soil-gas radon radiation levels in the Geleki oilfield ranged from 1 to 5 kBq/m3 over the subsurface reservoir with anomaly of enhanced values of 12–13 kBq/m3 around the periphery of the oilfield. It has been concluded from the observed soil-gas radon distribution patterns that drilling beyond the extent of the northwestern and eastern corners of the oilfield may yield potential subsurface oil accumulations.

Determination of Radon and Uranium Concentrations in Clay sediments of Household Water Tanks in Nineveh Province Using LR-115 Nuclear track Detector

Determination of Radon and Uranium Concentrations in Clay sediments of Household Water Tanks in Nineveh Province Using LR-115 Nuclear track Detector

Radon Monitoring as the Earthquake Precursor in Fault Line in Western Turkey

Variations in radon concentrations near the earth's surface can provide important information about seismic activities. Continuous monitoring of radon concentrations is one of the important steps in predicting earthquake mechanisms. This study monitored the radon concentration of an active tectonic zone in western Turkey. Four sampling stations in the seismic area, of the Tuzla fault line, were selected for radon monitoring. The online radon monitoring system was placed at Cumalý station. Concurrently, the radon concentrations in the soil gas were continuously measured using LR-115 nuclear track detectors and an online radon measurement system. Data obtained from Bogazici University Kandilli Observatory and Earthquake research Institute was incorporated in the analysis to correlate with the collected radon concentration. The radon concentrations were measured using solid-state nuclear track films (LR-115) in the soils of thermal water fields, which varied from 40 track cm -2 week -1 to 1580 track cm -2 week -1 .

Distribution of radon activity in the atmosphere above Wzgórza Niemczansko-Strzelinskie (South-WestPoland) and its dependence on uranium and thorium content in the underlying rock and indirect ground basement

Radon activity in the atmosphere and its behavior in the environment have been investigated using LR-115 nuclear track detector. The complex geological structure of Wzgorza Niemczansko-Strzelinskie (south-west Poland) enabled this problem to be studied in various geological conditions. The eU and eTh content in rocks and soil was measured by gamma-spectrometer GR-320. Uranium content of bedrock reached its maximum value of 15 ppm in the case of quartz-graphite schist. Thorium reached its maximum value of 35 ppm in the case of granodiorite. Radon activity was measured by means of long-term exposure of LR-115. The mean value of atmospheric radon activity was 21 Bqm-3 in the air 2 m above the ground surface. The highest radon activities were measured in the area of granite and quartz-graphite schist outcrops and in the area of mylonitic rocks of the Niemcza Zone. Radon activity in close to ground cup detectors varies from 25 to 300 Bqm-3, these values depend on uranium and thorium content in indirect ground basement (soil and weathered rocks). Not only uranium and thorium content but also rock disintegration due to tectonic events (shear zones) influenced atmospheric radon activity. Seasonal variation is not strong, although higher values were measured in the autumn- winter period.

Radon exhalation rate studies in Makum coalfield area using track-etched detectors

Radon exhalation rates were studied using LR-115 (II) nuclear track detectors in and around the Makum coalfield, which has significant geological features. Exhalation rates (mass and surface) from coal and soil samples were studied with reference to the geological features. The mass and surface exhalation rates from coal samples ranged from 6.1–16.2 mBq/kg/h and 201.6–535.7 mBq/m2/h, respectively. The mass and surface exhalation rates from the soil samples collected from the Margherita Thrust area of the coalfield and the coalfield area lying in between the Margherita Thrust and Disang Thrust of the coalfield were found to be 10.7 mBq/kg/h and 354.2 mBq/m2/h, and 9.5 mBq/kg/h and 314.2 mBq/m2/h, respectively.

Radon measurements in the residential colony of Nuclear Power Station at Kalpakkam using track detectors

It is an obvious fact that more than 55% of natural radiation exposure is due to isotopes of radon, a gaseous daughter product in both uranium and thorium series and is considered to be one of the causative factors for the increase in lung cancer cases. It was decided to create a baseline data of Radon levels in the dwellings situated in and around residential colony at Kalpakkam. Towards this, radon measurements were carried out in the new residential colony of Nuclear Power Station at Kalpakkam where large number of houses (independent bungalows, multi storied buildings) have been constructed. Solid State Nuclear Track Detector LR-115 films were exposed for one year covering the four seasons and processed using Spark Counter. The radon concentration level is even below the threshold action level of 200 Bq m - 3 as stipulated by ICRP ( 200 – 600 Bq m - 3 ) .

Radon anomaly in soil gas as an earthquake precursor

The mechanical processes of earthquake preparation are always accompanied by deformations; afterwards, the complex short- or long-term precursory phenomena can appear. Anomalies of radon concentrations in soil gas are registered a few weeks or months before many earthquakes. Radon concentrations in soil gas were continuously measured by the LR-115 nuclear track detectors at site A (Osijek) during a 4-year period, as well as by the Barasol semiconductor detector at site B (Kašina) during 2 years. We investigated the influence of the meteorological parameters on the temporal radon variations, and we determined the equation of the multiple regression that enabled the reduction (deconvolution) of the radon variation caused by the barometric pressure, rainfall and temperature. The pre-earthquake radon anomalies at site A indicated 46% of the seismic events, on criterion M⩾3, R<200 km, and 21% at site B. Empirical equations between earthquake magnitude, epicenter distance and precursor time enabled estimation or prediction of an earthquake that will rise at the epicenter distance R from the monitoring site in expecting precursor time T.

Radon as an earthquake precursor

Radon concentrations in soil gas were continuously measured by the LR-115 nuclear track detectors during a four-year period. Seismic activities, as well as barometric pressure, rainfall and air temperature were also observed. The influence of meteorological parameters on temporal radon variations was investigated, and a respective equation of the multiple regression was derived. The earthquakes with magnitude ⩾3 at epicentral distances ⩽200km were recognized by means of radon anomaly. Empirical equations between earthquake magnitude, epicentral distance and precursor time were examined, and respective constants were determined.

Uranium analysis of sediments by γ-ray spectrometry with corrections for self-absorption

We have applied the MCNP Monte Carlo program to calculate γ-ray counting efficiencies and the separate influences of sample density and composition in two of our geometries. Using the detector characteristics given by the manufacturer in the input, it was possible to reproduce experimental spectra obtained with given activities of 152Eu and 137Cs in H 2O. An equation for the self-absorption correction to be applied has been deduced as the ratio of the counting efficiency for a given sample to that of H 2O. With a parameterization of this correction factor as a function of γ-ray energy and sample density, we could improve γ-ray spectrometry results for uranium concentrations in sedimentary Moroccan phosphates. These results were compared with those deduced by contact autoradiography using the solid state nuclear track detectors LR115 and CR39.

Estimation of indoor radon, thoron and their progeny using twin cup dosemeters with solid-state nuclear track detectors in Digboi of Upper Assam

The seasonal variations of indoor radon, thoron and their progeny levels were studied in 20 houses situated in the oil-rich areas of Digboi of Upper Assam. Solid-state nuclear track detectors LR-115 type II were exposed using plastic twin chamber dosemeters to record tracks formed by the two gases and their progeny. Inhalation doses were found out using extracted equilibrium factors and ventilation rates. The random (counting) errors in track densities were determined.

A study of radon and thoron release from Egyptian building materials using polymeric nuclear track detectors

The free exhalation rates of both thoron and radon, the specific activities of 224Ra, and 226Ra, and the physical properties, such as the emanation coefficients and radon effective diffusion coefficient of several building material samples were determined using LR-115 and CR-39 polymeric nuclear track detectors. The free areal exhalation rate was measured by the sealed cup-technique, whereas the radium content was obtained by the alpha-autoradiographic method. The calibration coefficient for thoron measurements in air using cylindrical cup equipped with LR-115 detector was estimated. Moreover, the calibration coefficients for measurements of the specific activities of 224Ra and 226Ra were also evaluated. New method was developed for evaluating the emanation coefficient as well as the diffusion coefficient of radon isotopes in the studied materials.

Radon Dose and Aerosols

The equilibrium factor value (F) was measured in the NRPB radon chamber and the corresponding track density ratio (r = D/D0) of bare (D) and diffusion (D0) LR-115 nuclear track detectors was determined, as well as the regression equation F(r). Experiments with LR-115 nuclear track detectors and aerosol sources (burning candle and cigarette) were carried out in the Osijek University radon chamber and afterwards an empirical relationship between the equilibrium factor and aerosol concentration was derived. For the purpose of radon dose equivalent assessment, procedures for determining the unattached fraction of radon progeny were introduced using two nuclear track detectors.

Radon equilibrium factor and aerosols

Equilibrium factor values ( F) were measured in the NRPB radon chamber and corresponding track densities of the bare ( D) and diffusion ( D 0) LR-115 nuclear track detectors were determined. The obtained empirical function, F( D D 0 ) , has agreed with the theoretical one, that had been derived by using concentration equations for the radon and its short-lived decay products. Measurements of the detector track densities and aerosol concentrations ( c a) made possible a fitting of the D D 0 (c a ) function, that after introducing into the F( D D 0 ) gave a relationship for aerosol concentration, F( c a). So, it was possible to assess a radon dose equivalent if concentrations of radon and aerosols in the air were known (measured).

Study of the influence of the lithological and hydrogeological parameters of aquifers on the radon emanation from underground waters using solid state nuclear track detectors

Radon-to-thoron ratios as well as radon and thoron activity concentrations in different underground water samples belonging to different aquifers in the Moroccan Middle Atlas area have been evaluated by LR-115 and CR-39 solid state nuclear track detectors (SSNTD) using a new calibration method. The radon isotope (222Rn) was used as a tracer for studying the water exchange between different aquifers of the area studied. The influence of the lithological and hydrogeological parameters of the aquifers on radon emanation were investigated.

A new method for evaluating the influence of building materials on radon emanation in marrakechi Dwellings

Radon emanation has been studied in different rooms of buildings in Marrakech by using LR-115 and CR-39 solid state nuclear track detectors (SSNTD). A new calibration method has been developed based on calculating the probability for an emitted α-particle to be registered on a SSNTD. The thoron-to-radon ratios as well as thoron and radon activity concentrations in the dwellings studied have been determined by exploiting the measured track densities, due to the α-particles emitted by radon, thoron and their daughters, registered on the SSNTD. The influences of building materials, pollution and painting layers and papers were also investigated.

Radon in schools and dwellings of Osijek

Indoor radon concentrations were measured in 10 821 pupils primary schools of Osijek by means of the Radhome silicon detector. The values ranged from 15 to 300 Bq/m3 with the arithmetic and geometric means of 93.4 and 70.6 Bq/m3, respectively. Ten years continuous radon measurements performed with the LR-115 nuclear track detector in three houses of different construction and town area gave means of 27, 96 and 23 Bq/m3; the indoor Rn concentration for a heating period was a factor of 1.5 higher than for the warm season. The average effective dose equivalent for the primary school pupils was 2.8 mSv/y (with occupancy factors of 0.6, 0.2 and 0.2 for home, school and outdoors, respectively). For citizens of Osijek it was 1.7 mSv/y.