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In this paper, we investigate the impact of ultraviolet (UV) exposure on the bulk etch rate (V b ), track etch rate (V t ), and detector sensitivity of a CR-39 nuclear track detector. The study involves measuring the depths and diameters of alpha particle tracks in the CR-39 detector. The detectors were irradiated with alpha-particles with energy of 3.5 MeV after/or before being exposed to UV radiation at 366 nm for 6 h. The detectors were etched in a 6.25 N NaOH solution at 70 °C for periods of 1–7 h. The results showed that both V b and V t for CR-39 exhibited an enhancement when exposed to UV, where, the alpha-particle track diameters and depths increased with UV exposure. Moreover, the study revealed that the track formation time is decreased when the CR-39 detector was irradiated with UV light.

In this paper, Solid State Nuclear Detector (SSNTD) CR-39 was broken into many fragments with areas of (1x1) cm2. The samples were irradiated using 241Am source. The measurements were taken at normal incident angle of the alpha particles for energies (3.17, 3.59 and 4.13) MeV respectively. The samples were etched using sodium hydroxide solution (NaOH 6N, 70±1 oC) for time interval of 0.25 h. The optical microscope provided with digital camera was used to preview the track profile formed in CR-39. This allowed measurement of the track length and in turn the track length as a function of the etching time . The track growth rate, track etch rate and track rate ratio were also investigated as a function of many parameters such as etching time, track depth and residual range. The study showed a good consistency among the investigated parameters . The curves of the track etch rate and track etch ratio manifested a consistency with Brack curve who interested in studying the linear energy loss in materials where the maximum energy loss occurs at the end of the alpha particle range.

Radon (222Rn) is a radioactive gas, from the 238U decay chain, that contributes in large part of the natural radiation dose to which humans are exposed. Radon is the second cause of lung cancer after tobacco. The US-EPA considers a concentration of 148 Bq/m3 for homes and 400 Bq/m3 for workplaces as the reference level. Caves are closed spaces where 222Rn, which emanates from the surrounding minerals and rocks, can accumulate and reaches large concentrations that can represent a health risk for the guides, speleologists and visitors who spend time in these spaces. This work uses the previously recorded radon concentrations in 8 caves in Mexico and calculates the average dose range and the average annual dose for each of them with the “Wise” public domain program (http://www.wise-uranium.org/rdcrn.html) to determine the level of radiological risk with 2,000 1,000 and 500 working hours per year. Karmidas cave had the highest average 222Rn concentration with 27,633.3 Bq/m3 and for 2,000 working hours per year an average annual dose rate of 347.1 mSv/y. Los Riscos cave had the lowest average concentration with 384.7 Bq/m3 and for 2,000 working hours per year an average annual dose rate of 4.832 mSv/y. These results show that all the caves studied present values,with 2,000 working hours per year, that exceed 3 mSv/y for workplaces and must be considered by the people who work in these places. A casual tourist visiting the caves does not present any radiological risk, while guides and speleologists should consider it.

This article tests the feasibility of using the diameter-length (Le-D) technique to determine the bulk etch rate (Vb) in a CR-39 nuclear track detector. The detector was irradiated with alpha particles energies: 5.3, 4.7, 4.1 and 3.5 MeV, which were emitted from a 241Am source. The detector was etched in a 6.25 N NaOH solution at 60 °C for periods of 1–10 h. The average Vb found by means of the (Le-D) method is approximately 0.76 ± 0.05 µm/h, which is consistent with the result found separately by the thickness-measurement method (i.e. 0.836 ± 0.06 µm/h). Moreover, the results show that the Vb of the CR-39 detector is independent of the alpha energies. This can pave the way for the use of the (Le-D) method as a reliable alternative method for measuring the bulk etch rate.

In this paper, the nuclear track detector CR-39 with a thickness of 200 µm is divided to several pieces. The area of one piece is 1 x 1 cm2. This study has involved two parts. Fist part is without irradiated by alpha particles. The second is irradiated by alpha particles with energy E = 1.2 MeV using the 241Am radioactivity source and incident angles (0, 10, 30, 50)o. All samples etching with sodium hydroxide solution at a concentration of 6.25 N and a temperature of (70 ± 1) oC. The study included calculating track parameters and comparing them with the results of the first equation from the Track-Test program. This comparison showed that there is a good agreement between experimental results and Track-Test data for track profile. In this paper, the nuclear track detector CR-39 with a thickness of 200 µm is divided to several pieces. The area of one piece is 1 x 1 cm2. This study has involved two parts. Fist part is without irradiated by alpha particles. The second is irradiated by alpha particles with energy E = 1.2 MeV using the 241Am radioactivity source and incident angles (0, 10, 30, 50)o. All samples etching with sodium hydroxide solution at a concentration of 6.25 N and a temperature of (70 ± 1) oC. The study included calculating track parameters and comparing them with the results of the first equation from the Track-Test program. This comparison showed that there is a good agreement between experimental results and

Tauc analysis is popularly used for the determination of optical band gap by extrapolating the linear portion of the Tauc’s plot and finding its intersection point at energy axis. In most of the st...

Environmental monitoring for outdoor and indoor radon is very significant for public health to evaluate the probability of developing respiratory system cancer, and to offer proper procedures that reduce the outdoor or indoor radon concentration. In southern Iraq, several cases of various types of cancer injuries have been reported in the literature. In this work, the radon concentration in the clay soil in Abu Al-Khaseb and Ad Dayer districts in Basra province in the south of Iraq has been measured in 18 samples collected from different depths. The mean values obtained for radon activity concentration in Abu Al-Khaseb and Ad Dayer were found to be 64.8 ± 0.9 and 80.9 ± 0.9 Bq m−3, respectively. The outcomes demonstrated that radon's concentration in both locations is within the safe range recommended by the World Health Organization WHO and the International Commission on Radiological Protection ICRP. The mean values of the estimated radiation hazard indices include the equilibrium equivalent radon concentration, the potential alpha energy concentration, the annual absorbed dose, the annual equivalent dose, the excess lifetime cancer risk, and the lung cancer cases per year per million people are well within the acceptable limits in both regions (45.3 Bq/m3, 0.01 mWL, 0.2 mSv/y, 0.4 mSv/y, 1.4, and 2.7 mSv $$\times {10}^{-6}$$ /y in Abu Al-Khaseb and 56.7 Bq/m3, 0.02 mWL, 0.2 mSv/y, 0.5 mSv/y, 1.7, and 3.4 mSv $$\times {10}^{-6}$$ /y in Ad Dayer, respectively). The areas under study are considered to be safe and do not pose any risk for inhabitants. Results obtained in this work were compared with other locally obtained results, and there is no significant variation in radon concentrations from one region to another.

The most used passive detectors for Radon measurement are the CR39s, both for the good stability of the material and for the practicality of use. But, commercial reading systems are expensive and not always fast. The aim of the present work was the development of a method for a rapid, efficient and economic evaluation of the result of the indoor Radon measurement performed with CR39 detectors. The analysis and acquisition of detector images were performed using a photo scanner and the free ImageJ software. Several groups of CR-39 detectors were exposed, developed and analysed. Calibration curve was obtained in a wide range of exposure values (200–12 000 kBq·h·m −3) to allow the procedure to be applied in all possible measurement environments. Furthermore, a statistical study was carried out on the shape and size of nuclear tracks after chemical development. The dependence of the track size on Radon exposure was effective in showing the trace saturation effect as well.

In this present work, radon concentration was measured indoor buildings in the College of Education for Pure Sciences / Ibn Al- Haitham University of Baghdad using Rad-7and CR-39 detector for compare, because this college is one of the old buildings, also there are some closed places inside it, where increase radon gas in these places will cause to health hazard. Rad-7 monitor is used to measure the radon concentration in three ways in the air, water and soil. In this work, Rad-7 was measured radon concentration in the air which is direct method with compared CR-39 detector which considers passive method of measurable. Have been measured for half an hour in every room using Rad-7 with appropriate conditions for measurement, where the device was recorded higher reads in two samples F1 and F2, the values were (59.6 Bq/m3) and (48.2 Bq/m3) respectively and the lowest read in the sample (E1), the value was (5.43Bq/m3). When using CR-39 detectors were placed two detectors of CR-39 in every room for (30) days, the results were (445.868Bq/m3) and (436.791Bq/m3) respectively because these places without ventilation and very old buildings and the lowest read in the sample (C1), the value was (17.412Bq/m3) because these places were open and with high ventilation. All results that recorded by using Rad-7 monitor were within the range allowed globally recorded by (ICRP) but the results of CR-39 were within the range allowed globally recorded by (ICRP) which were (200-300)Bq/m3 except two samples F1 and F2.

In this study, radon concentration was examined in surface water samples taken from Van Lake in spring and autumn. The samples were taken along the coastline from Tatvan, where the active fault line lies, until Erciş. Analyses were performed by using CR-39 solid nuclear track detectors and RadoSYS radon measurement system. Radon measurement parameters (CRn, Es, Em and ECRa) were calculated with the data obtained. The results obtained in the study were compared with the limit values given for radon in water and the results obtained in similar studies.

Introduction: Radon is a radioactive gas released from the normaldecay of uranium in rocks and soil depending on local geology. Radioactive decay of uranium through radium produces radon. Materials and Methods: In the present work, seventeen plant (vegetables) samples collected from Sulaimania Governorate. The plants have been analyzed and examined to measure the level of radon (222Rn) and thoron (220Rn) using plastic track detector (CR-39) for evaluation of radon and thoron concentration in this region. Results and Discussion: The results indicated that the higher andlower radon concentration have been found in Halabjay-con, and inSulaimani-center, to be (119.72 Bq.m-3, 3.236 pCi/L), (54.36 Bq.m-3,1.469 pCi/L), respectively, and the higher and lower thoron concentration have been found in Qaladza and in Sulaimani-center, to be (733.66 Bq.m-3, 19.828 pCi/L), (227.33 Bq.m-3, 9.117 pCi/L), respectively. Radiation level compared with the standard level known by the EPA (4 pCi/L) and190 Bqm-3. The concentration of radon in all sample plants is less than international standard level 4(pCi/L)and190 (Bqm-3), therefore the human in safety. The average effective dose equivalent (EDE) of radon from plants determined was (7.2) μSv.y-1 for all the samples. This is lower than the normal value of (1.3) mSv.y-1 given by EPA. Conclusions: This study showed that the contamination in the plant (vegetables) is normal and is not considered a great radial dose for plants and consequently for humans.

Environmental samples like soil, building materials and decorative materials are the major source of indoor radon. The contribution of these environmental materials toward indoor radon level depend upon the radium content and radon exhalation rates and can be used as a primary index for radon levels in the dwellings. Sealed cup technique was used to determine the radon exhalation rates and the effective radium content in different environmental samples collected from Jazan city, Saudi Arabia. Back diffusion is the main removal processes of radon from its sealed cup which leads to underestimate the measured parameters. To assure the quality of the measurements, the results were corrected for back diffusion effect and checked for the effect of sample mass on the measured parameters. The combined uncertainty was also calculated taking into consideration the possible sources of uncertainty. The overall weighted mean of areal exhalation rate (EA) and effective Radium content (Raeff) for soil samples collected from different 10 districts in Jazan city is 17.02 ± 2.06 Bq m−2d−1, 3.01 ± 0.37 Bq kg−1 respectively. For 20 Building materials samples, EA = 1.989 ± 1.056 Bq m−2d−1 and Raeff = 0.351 ± 0.186 Bq kg−1. Finally, for decorative materials (23 samples), EA = 1.225 ± 0.136 Bq m−2d−1 and Raeff = 0.427 ± 0.031 Bq kg−1. The maximum values of the measured parameters are found in the soil of scheme 5 and 6 district, red sand (building material) and gypsum (decorative material). As the mass of the sample increase, more and more radon diffused back into the sample and the measured effective radium content is reduced. After correcting the results for back diffusion effect, all masses approximately get the same value of effective radium content and then reduced the uncertainty in the weighted mean.

Generally, in Nigeria dumpsites are open and elevate the pollution by increasing the total environment contamination level. This affects not only the site of dumpsites but also the surrounding buildings and area. In the present work, indoor radon activity concentration is tested inside some buildings in the vicinity of dumpsites in Lagos, Nigeria. A passive technique with CR-39 detectors is used. Different buildings around different eight dumpsites were chosen. Radon concentration had ranged from 16.00 ± 3 to 931.00 ± 186 Bqm−3 in the dumpsites. With Mean concentrations range from 120 ± 24 at OKE-ODO to 334 ± 67, at Solus-4 respectively. The present results explain that 63% of the radon activity concentration in indoor air around the selected dumpsites at Lagos city in Nigeria is below the allowed limit from ICRP 200 Bq m-3 while 37% is more than this limit. Based on the measured radon concentration, the annual effective dose and cancer risk are evaluated. The range of ELC is from 242 to 14086 with mean value 3114 ± 1111.

In this work, a new empirical equation is used to describe the track length evolution against the etching time, alpha particle energy and track longitudinal length respectively. In this equation, six fitting parameters are employed in order to achieve reasonable fitting. The tracks length formed on the CR-39 by alpha particles, at different energies and etching times, can be reproduced using this empirical equation. The fitting parameters extracted from the experimental data can be used to predict etched track lengths at different energies and etching times which are capable of reproducing all the features of track length evolution as a function of etching time and particle energy.

In this work, radon gas concentration in (35) samples of soil collected from Karabuk University in Turkey was measured by using nuclear track detector (CR-39). The content of radium, the rate of surface exhalation and the rate of mass exhalation have been assessed. The concentrations of radon were varied from (16.348 Bq.m−3) to (196.988 Bq.m−3). Results indicate that the equivalent content of radium varied from (0.386245 Bq.kg−1) to (4.654255 Bq.kg−1). The exhalation rate for surface varied from (0.002007 Bq.m−1.h−1) to (0.023031 Bq.m−1.h−1). The exhalation rate for mass varied from (0.000319 Bq.kg−1.h−1) to (0.00366 Bq.kg−1.h−1). All the obtained results found to be less than the corresponding limits for the world. Thus, based on the radon gas concentration and radiation, the equivalent content of radium (CRa), exhalation rate for the area (EArea) and exhalation rate for the mass (EMass) in this area have no risk to the human’s health.

In this work, eighteen samples were studied distributed over different sites in Basra Governorate from southern Iraq. The CR- 39 nuclear trace detector technique was used to reach the results, which showed us, the radium concentrations ranged between (18.52 - 2.169) Becquerel / kg, the environmental factors such as rain, dust and weather erosion have led to a decrease in radium concentrations in these areas which fell within the permissible range of 33 Becquerel / kg. The concentrations of uranium in the samples under study ranged from 0.2622 ppm to 2.239 ppm, is higher than the natural limit of the background radiation (0.2 - 1.2) ppm, which indicates that radioactive pollution has entered the Iraqi environment. As well as, we find that the concentration of Radon The samples have risen by twenty times the normal limit in some samples, which indicates the danger of dealing with the polluted southern environment of Iraq.

CR-39 detectors were used to detect high energy particles produced during Pd/D co-deposition. Upon completion of the experiments, the detectors were subjected to either microscopic examination, scanning using an automated scanner to obtain quantitative information on the tracks, sequential etching, or linear energy transfer (LET) spectrum analysis. Both the sequential etching and LET analysis allowed speciation of the particles that caused the tracks as well as estimating their energies. In these experiments it was shown that the tracks coincide with the placement of the Pd deposit. The average number of tracks obtained as a result of Pd/D co-deposition is more than 133 times greater than that found in the background. In this communication, the results of microscopic examination, scanning, and LET analysis are discussed.

This study examines the levels and the correlation between indoor and in soil radon concentration in a desert climate. The measurements are carried out, in Jordan desert in AlMafraq district, using the passive integrated technique. An intelligent automated tracks counting system, modified recently by our group, is used to estimate the overlapping tracks and to decrease the counting percentage error. Results show that radon concentration in soil expands from 4.09 to 11.30 kBq m −3 , with an average of 7.53 kBq m −3 . Indoor radon concentrations vary from 20.2 Bq m −3 in the AlMafraq city to 46.7 Bq m −3 in Housha village and with an average of 29.6 Bq m −3 . All of individual indoor radon concentrations are lower than the limit (100 Bq m −3 ) recommended by WHO except two dwellings in Housha village which found being higher than this limit. A moderate linear correlation (R 2 =0.66) was observed between indoor and in soil radon concentrations in the investigated region. Our results showed that an in soil radon measurement can be a satisfactory predictor for indoor radon potential.

Tea is one the most food used in the form of cold and hot drinks in Iraq, so 12 samples of the most frequently traded teas have been collected on the market, where Radon and thoron levels were measured using CR-39 nuclear track detector, and exhalation rates of radon and thoron gas were calculated. The results show that the highest concentration of radon is in sample T-4 and the highest concentration of thoron is in sample T-5 and were 34.725 ± 13.2 Bq/m3 and 10.164 Bq/m3 respectively. The obtained radon levels is within the natural limits of the activity concentrations of the naturally occurring radionuclides in foods, and this will not form any risk on human health.

In this work, the track etch-rate VT and etch-rate ratio V of CR-39 detector irradiated by alpha particles was investigated at different incident angles. The change of the track etch-rate and etch-rate ratio along the particle trajectories showed that these functions are not affected by the inclination of the particle trajectory with respect to the normal on the detector surface.

In recent years, solid state nuclear track detectors (SSNTD) have been used increasingly in variety of field ranging from archeology and geophysics to fission physics and space research. In nuclear physics their advantages lie in their small and flexible geometry, in their ability to withstand high temperature and in their being able to discriminate against high background of less ionizing radiation. When ionizing radiation falls on a SSNTDs detector it produces minute trails of damage (perhaps 10-100 A° in diameter) in a material whether by the thermal spike effect of more by ion explosion effect. We in this work irradiate CR-39 SSNTD detector sample by ion beam of 93Nb with varied energy in the range 20 MeV to 1600 MeV. The damage trials produced were enlarged thousand times by subjecting the material to a suitable etching process (6N NaOH at 60°C Temperature). Then using continuous process of etching the maximum etchable track length was measured. Using well established SSNTD techniques the range and energy loss of the ion in polymer was calculated. The experimental result was then compared with theoretical data of SRIM and DEDXT programme. The theoretical data are in close agreement with our data.

In this study, the radon gas concentration as well as the annual effective dose in leaves of the Malvasylvestris (Khabbaz) plant used in the traditional treatment and as food in Iraq, for this, it is necessary to evaluate the concentrations radon gas, which were measured using solid state nuclear track detectors (SSNTDs) CR-39 technique. The concentration and annual effective dose in samples were collected from Baghdad city ranged from minimum to maximum value 15.815 , 0.498 , 54.445 , 1.717 respectively, while the values of concentration and annual effective dose in a sample collected from Karbala are 15.297 ,0.482 . These values of concentration and annual effective dose less were compared with the samples from Baghdad. The annual effective dose lies well within the safe limits as recommended by WHO. So, the uses of Malvasylvestris plant are in traditional medicine and as a safe food for human consumption.

Measurements of radon gas concentrations with their progeny and the annual effective dose indoor the building of Al-Mustansiriyah University College of Science-Physics Department have been carried out by using time-integrated passive radon dosimeters solid state nuclear track detector CR-39 technique. The detectors with 1cm x1cm have been distributed over 70 places and suspended for sitting (1m) and standing (1.75m) positions in each location under study. The dosimetric measurements are made over a period of 90 days from 30 January 2014 to 30 April 2014. The calibration process has been done using radium-226 source with known activity radiation. It has found that the indoor radon gas concentrations varing from 37.488±6.123Bg/m3 to 58.670±7.660Bg/m3 with an average value 51.398±7.156Bg/m3 at 1m , and varing from 35.964±5.997Bg/m3 to 56.994±7.549Bg/m3 with an average value 47.057±6.847Bg/m3 at 1.75m which are within the worldwide limits 148Bg/m3 (EPA, 2003) and 200-300Bg/m3 (ICRP, 2009). The annual effective dose of the inhalation exposure to radon gas has been estimated and this vary from 0.394mSv/y to 0.617mSv/y with an average value 0.540mSv/y at 1m, and varing from 0.378mSv/y to 0.599mSv/y with an average value 0.495mSv/y at 1.75m which are within the worldwide permissible limist 3-10mSv/y (ICRP, 1993). The potential alpha energy concentration found to vary from 4.053mWL to 6.343mWL with an average value 5.557mWL at 1m and vary from 3.888mWL to 6.162mWL with an average value 5.087mWL at 1.75m which are less than the recommended value 53.33mWL (UNSCEAR, 1993). The lung cancer cases per million person per year vary from 7.093 to 11.101 per million person per year with an average value 9.725 per million person per year at 1m and vary from 6.805 to 10.784 per million person per year with an average value 8.904 per million person per year which are less than the recommended range 170-230 per million person per year (ICRP, 1993). The number of decays per-minute using swabs measurements technique have been used for selected units within two swabs from building materials walls for each unite, with area of 100cm2 using Ludlum 3030, the average of three swabs measurements have been calculated. Hence, the effectiveness of emitted alpha particles from the walls has been calculated to be varied from 0.00000 to 0.02222Bq/cm2 with an average value 0.01169Bq/cm2 at 1m and 0.01015Bq/cm2 at 1.75m respectevily which are within the permissible limit 0.04Bq/cm2 (Danial, 2010).

The research aims to measure the uranium concentration of soil samples collected from different regions are located around the nuclear research center at Tuwaitha to a contamination ratio statement of these regions, which include agricultural residential regions as well as being the regions for livestock of all kinds. The nuclear track detector (CR39) was used as a method to detect uranium of through calculations depended on comparison with standard samples. Results indicate that the uranium concentration ranged between (0.4ppm) and (2.538 ppm), these results are within allowed limit that equals (11.7 ppm).

Hajjam Island lies in the lower reaches of Khor Al-Zubair southern of Iraq, it is the unity island in the Iraqi marine water. 15 sediment samples were collected from sites around the island and transferred to the lab in Marine Science Centre for radiological investigation. Two methods were adopted, Active and Passive, for determination of Radon in which an environmental radon monitoring system comprising a radon-cup, an etching system, and a track counting system, was constructed. The radon cup is a cylindrical chamber with a radius of 3.5 cm and a height of 15 cm in combination with a CR-39 detector. The effected radium concentrations from sediment samples were found to range from 0.0013 to 0.0049 with an average value of 0.0028 Bq/Kg. Concentrations of radon measured by passive method were 132±34 to 414±108 with average value 287±45 Bq/m 3 and by active method were 401±26 to 145±9 with average value 263±20 Bq/m 3 . The area and mass exhalation rates were found to be 0.1 to 0.31 with average value of 0.220 Bq/m 2 /h and 0.002 to 0.006 with average value 0.004 Bq/kg/h respectively. The values are found to be safe for sediment use.

The present study focuses on determination of alpha particles concentration in different samples of toothpaste by using nuclear track detector (CR-39). Nine samples of toothpaste have been collected from local Iraqi markets in Babylon Province. These samples have been chosen according to their most commonly use in Babylon Province. The samples were kept with CR-39 detector for six weeks period and then etched by 6.25 N of NaOH solution at temperature of 60°C for 5 hours. The results of the present work show that Sample 3 (Frosty) found to have a high alpha concentration about four times compared with Sample 4 (Aquafresh) and about 2 - 3 times compared with other samples.

In the present study twenty-two vegetable samples were collected from Iraqi market. Sealed can technique using CR-39 plastic track detector strippable has been used in order to measure radium and uranium concentrations. Etching was done with 6.25 N NaOH and optical microscope was used with the purpose of counting of alpha particle tracks. The values of effective radium content are found to range from 0.074 Bq/ kg to 0.566 Bq/ kg with the mean value of 0.317 Bq/kg. The values of uranium concentrations are found to range from 0.081 ppm to 0.615 ppm with the mean value of 0.345 ppm. Positive correlation has been observed between radium concentration and uranium concentrations in vegetable samples. Measurements of radium and uranium concentrations in vegetables are important from the health protection point of view, so simple and reliable analytical methods must be available.

E FFECTS of ageing on the optical properties of CR-39 SSNTDs were investigated for two stored types. The optical band gap of the stored pristine was roughly the same as the new pristine samples before chemical etching. Energy gaps were found to decrease with the chemical etching. The onset of the transmittance spectra of the CR-39 SSNTDs were measured at 240 nm and 300 nm for 26 y and 10 y respectively. The etch pit diameters of α−particles were deceased with the storage period while the rate of the decrease depended markedly on the storage conditions. The fading effects of tracks due to radon exposure were a little bit changed. The storage at the temperature of 4 °C for 26 y did not bring any significant changes to the detection efficiency. These characterizations of the response of CR-39 SSNTDs to alpha particle were essential for the storage under certain conditions.

In this study, we show that angular measurement of nuclear tracks produced in heavy ion interactions can be made with high precision using a CR-39 solid-state nuclear track detector. For this purpose, we have increased the position resolution of nuclear track (etch pit) analysis and the precission of thickness measurement of the CR-39 detector. The position resolution of the heavy ion track was verified to be 0.02 μm by the dedicated image analysis software package PitFit. The precision of the thickness measurement of the CR-39 detector was increased to 0.6 μm by our new both sides imaging method of the CR-39 detector using the autofocus system of the microscope. As a consequence, the angular distributions of projectiles and fragments can be realized with a precision of 1.4 × 10−2 degrees (2.5 × 10−4 radian). As a demonstration, we applied the angular measurement technique to the diagnosis of heavy ion beam and the small Coulomb scattering angle measurement of interactions of 12C + Al in energies below 100 MeV/nucleon. By this new imaging technique, event-by-event interaction of the projectiles in the CR-39 detector can be measured rapidly and can be applied to the measurement of the total charge-changing cross section, the decay mode, and the branching ratios of the projectile with higher angular precision.

Wheat and barley crops are used as food by humans and animals, their health effects on human life must be under the control, so it is important to measure their radiation concentrations. This work aimed to determine radon, radium, and uranium in barley and wheat crops planted in the Nineveh plains region. The technique of alpha track registration by CR-39 detector is used in measurements of the samples from ten planted locations. Radon, radium, and uranium mean concentrations found are 92.58 Bq.m−3, 0.4212 Bq kg−1 and 0.368 ppm, respectively. The uranium activity concentration and the total annual effective dose equivalent mean values are 4.546 Bq.kg−1 and 67.73 μSv/y. The results showed that the activity in locations depends on the agriculture soil of the area, and the amount of fertiliser applied in soil. All results are below the world permissible limits so the wheat and barley in the studied area are safe for consumption.

The aim of this study was to investigate the effect of ageing and fading on PADC detector response, as a function of the storage time and temperature. Several groups of CR-39 detectors provided by Radosys, Ltd. were exposed at the reference radon chamber of the Istituto Nazionale di Metrologia delle Radiazioni Ionizzanti, at the ENEA centre in Casaccia. The results indicate that low-temperature storage inhibits the effect of both ageing and fading. Finally, the overall reduction in CR-39 sensitivity due to the combined ageing/fading effect was estimated. In particular, the sensitivity of the detectors continuously exposed in air at room temperature over 6 and 3 months was reduced, respectively, by 7.5 and 4 %. © The Author 2014.

In this work, we have study the concentration of radon gas in seven cement samples from different regions in Iraq (Kofa, Sulaymaniya, Kubesa, Karbala, Al-Kaem, Basra, and Almas cement) by using alpha-emitters registrations that emitted from radon gas in CR-39 nuclear track detector. Sealed-cup technique that used in this study to determine the alpha emitters from radon gas. The results obtained shown that the highest average radon gas concentration in cement samples which was (55.16 Bq/m3) for Almas samples, while the lowest average radon gas concentration in cement samples which was (24.13 Bq/m3) for Karbala samples. The current results show that the radon gas concentration in all cement samples that studied is below the allowed limit from International Commission of Radiation Protection (ICRP) agency.

Determination technique of radon exhalation rate (RER) from soils in field measured by track detector CR-39 was developed. For this purpose, the method “Russian dolls” (matrieshka) was created and used, consisting of three cylindrical plastic chambers and located inside each other. Entrance mouths of chambers are installed in opposite directions to make an artificial barrier up on the path of 220Rn. Field measurements of the RER from soils were within 16.4–22.1 Bq/m2h, that are 160 and 220 times more than laboratory measurement. The RER values from soils as laboratory and field measurements have been compared with the data of other authors.

This study documents measured radon concentration levels in Coves de Campanet, a touristic cave from Mallorca (Spain). The mean annual concentration at eight different locations within the cave varied between 644.37 and 1,694.40 Bq m−3. As expected, a seasonal variation was observed, with higher radon levels during summer and lower values during the winter season. The integrated measurements were confirmed by continuous radon monitoring in two selected locations. The effective dose expected to be received by tour guides within the cave ranged from 0.72 to 1.89 mSv y−1 with an annual dose of 1.23 mSv y−1.

The solid state nuclear track detectors (SSNTDs) have been used in diffusion chambers for long time measurements of radon gas concentration. There is a direct proportion between the number of traces on SSNTDs and the activity concentration of radon with proportion coefficient that is called calibration coefficient (detection response). In this paper, partial and total detection responses of a CR-39 solid state detector in a conical chamber have been measured analytically and experimentally. Using these solutions, calibration coefficients have been drawn in terms of different dimensions of conical chambers. The results are compared with the experimental results of this work and the others.

Long term outdoor radon measurements were recorded in Ireland using CR-39 track etch detectors. A measurement protocol was designed for this study, which was optimized for the relatively low radon concentrations expected outdoors. This protocol included pre-etching the detectors before exposure to allow radon tracks to be more easily distinguished from background. The average outdoor radon concentration for the Republic of Ireland was found to be 5.6 ± 0.7 Bq m(-3). A statistically significant difference between inland and coastal radon concentrations was evident but no difference between mean radon concentrations on the east coast and those on the west coast was observed.

The calibration factor of 0.029 ± 0.0002 track cm−2 per Bq d m−3 for radon concentration measurements was determined using CR-39 and RAD7 detectors. The 222Rn concentration varied from 2,225 to 9,950 and 12 to 1,002 Bq m−3 in soil and water, respectively. The highest radon exhalation and gamma dose rates were found in Acid and undifferentiated granitic rocks and Miscellaneous soils.

Radon concentrations in fertilizer samples collected from agricultural areas in Cameron Highlands and Penang, Peninsular Malaysia were studied throughout this paper. The concentrations were measured using a sealed-can technique based on the CR-39 SSNTDs. Results indicate that the concentration of radon in the phosphorus sample was the highest whereas the minimum values were found in CDM (Cow dung manure). The levels of radon concentration were found to lie within the range of (634.0151.42 to 79.2523.24) Bq m-3.

A spectrometric study of alpha particles using CR-39 solid state nuclear track detectors is described. It is based on the application of software imposed selection criteria, concerning the geometrical and optical properties of the tracks which are created by alpha particles of specific energy falling on the detector at given angles of incidence. These selection criteria are based on a preliminary study of tracks’ parameters (major and minor axes and mean value of brightness), using the TRIAC II code. Since no linear relation was found between the energy and the geometric characteristics of the tracks (major and minor axes), we resorted to the use of an additional parameter in order to classify the tracks according to the particles’ energy. Since the brightness of tracks is associated with the tracks’ depth, the mean value of brightness was chosen as the third parameter. This method could be applied as a low cost technique in studies concerning the radon’s daughters 218Po and 214Po behavior in air.