CR-39 Track Detectors Research Articles

Innovative utilization of compact disc for measuring fast neutron generated from a 10 MV medical linear accelerator

Background: High-energy photons produced from a medical linear accelerator (LINAC) have long been used as one of the most effective ways for treating cancers. During the treatment process, some photo neutrons are unavoidably created by [γ,n] reactions, imposing additional and undesirable dose on a patient. This amount of unplanned dose from photo neutrons can potentially harm the patient as well as medical personnel during the treatment. This study is aimed to develop a methodology for measuring fast neutron dose generated from 10 MV LINAC by employing polycarbonate from base material of compact disk (CDs) and a fast neutron converter. Materials and methods: The polycarbonate base layer of CDs has been applied to fast neutron dosimetry with nuclear track method by combining with polymethyl methacrylate (PMMA) converter for fast neutrons. A number of CDs badges were irradiated with high energy photon from 10 MV Elekta Synergy LINAC in the solid water phantom at depth of 0, 2.5, 5, 10, 15 and 20 cm then etched with potassium hydroxide ethanol water (PEW) solution that containing with potassium hydroxide, ethanol and water with ratio of 15:45:40. The optimal condition for the chemical etching were found at 60±2 °C, for 14 hr. Results: Comparison of neutron equivalent doses from measurement of CD track detector and CR-39 track detector has shown that the maximum fast neutron dose equivalent was at depth of 5 cm of phantom. This agreement has confirmed that the CD track detector can be employed to measure fast neutron doses produced from LINAC in an accurate and affordable fashion. Conclusion: It is confirmed that the CD track detector can be employed to measure fast neutron doses produced from LINAC in an accurate and affordable fashion.

Calculation and determination of radioactivity in the old district of Najaf by using the track detector CR-39 and geographical information systems (GIS) methods

<abstract> <p>This research aims to study the radiation concentration distribution of the old District of Najaf (Iraq), where 15 samples were taken from featured sites in the District, which represents archaeological, religious, and heritage sites. Track detector CR-39 was used to calculate the concentration of three different soil weights for each sample site after being exposed for a month. Geographical information systems (GIS) were used to distribute the radioactive concentration on the sites of the samples, where two interpolation methods, namely the inverse distance weight method (IDW) and the triangle irregular network method (NIT), to study the distribution of the radioactivity concentration. The study showed that the western part of the district, which includes the old cemetery and the areas adjacent to the Najaf water depression, are characterized by a relatively high amount of radioactivity concentration compared to the eastern part, which represent the residential areas, and for all sample weights.</p> </abstract>

Annual Committed Effective Dose from Various Phytotherapeutic Preparations (due to <sup>238</sup>U, <sup>232</sup>Th, <sup>222</sup>Rn and <sup>220</sup>Rn) Estimated for Adult Moroccan Patients

We use a nuclear technique based on the determination of the detection efficiencies of solid state nuclear track detectors CR-39 and LR-115 type II (SSNTDs) for alpha particles emitted from the series of uranium-238 and thorium-232 in a phytotherapeutic sample and the measurement of alpha track densities registered on these detectors to assess alpha activities due to uranium-238; thorium-232; radon and thoron in samples of phytotherapeutic preparations consumed by Moroccan adult patients. For modern preparations, the alpha activities due to 238U, 232Th and 222Rn range from 14.27 mBq/kg to 22.02 mBq/kg, from 6.27 mBq/kg to 9.64 mBq/kg and from 14.27 Bq/kg to 22.02 Bq/kg respectively. For classical preparations, the alpha activities due to 238U, 232Th and 222Rn range from 16.73 mBq/kg to 24 mBq/kg, from 7.34 mBq/kg to 10.82 mBq/kg and from 16.73 Bq/kg to 24.72 Bq/kg respectively. A dosimetric model for ingestion has been highlighted to determine committed equivalent dose to different compartments of human gastrointestinal system due to the ingestion of phytotherapeutic preparations by Moroccan adult patients. The maximum overall effective dose due to 238U, 232Th, and 222Rn after the ingestion of the studied phytotherapeutic preparations, was found equal to 38 × 10-8 S·vy-1 which is less than the dose limit given by the international commission for radiological protection in it publication 56.

Measurement of 222Rn gas Concentrations and Radon Exhalation Rates in Some Cigarettes Tobacco Samples

Twelve cigarette tobacco samples of various brands and origins were gathered from local markets of Iraq. . The CRn was determined utilizing CR-39 track detectors which were exposed to the various brands of cigarettes tobacco for 45 days. The results demonstrated that the highest value of 222Rn concentration was )157 Bq/m3( in Macbeth cigarette sample of Brazilian origin and the lowest value of CRn was (76.3 Bq/m3 (in Sumer cigarette sample of Iraqi origin,with an average value of (106.53±22.3 Bq/m3). The outcomes have demonstrated that cigarettes of a Brazilian origin contain higher CRn than other studied samples, however, it is still less than some other average values given in the literatures.

Indoor Radon Concentration and Risk Estimation: the EURA PROJECT

The indoor radon concentration level has been monitored in selected locations in four European countries (Iceland, Italy, Norway, and Sweden) during a yearlong measurement campaign using time-integrated passive radon dosimeters containing CR-39 track detectors. The measurements were carried out in private houses and public buildings like schools, for an exposure time of up to 6 months for each detector. Experimental data shows a great variation between different geographic areas, and often the average levels are over the acceptable radon limit of 300 Bq/m3recommended by the International Commission on Radiological Protection (ICRP). To investigate a relationship between indoor radon exposure and lung cancer, estimating the cumulative levels of exposure to indoor radon for an individual or population is necessary. We analyse the data sets and investigate the factors influencing indoor radon concentrations in order to determine the best use of the experimental information. The results show that the variables associated with indoor radon levels are strictly linked to the soil geology. Analyzing the data sets enables improved assessment of radon exposure in a given area. The average absorption effective dose equivalent for a person is computed, and the risk of lung cancer per year is evaluated. Doi: 10.28991/HEF-2021-02-04-01 Full Text: PDF

Experimental Investigation to Determine the Concentration of Radon in Cosmetics Using a Nuclear Track Detector (CR-39)

The nuclear track detector CR-39 is used in the detection of radon gas concentration in selected samples of cosmetics in the local market. Products of wide use are selected and employed in the current study. Six types of cosmetic products of different origins are tested by taking equivalent quantities of these products and putting them in plastic boxes. The detector is left with the samples for a period of 50 days. In addition to measuring the rate of surface evaporation of radon gas, measurements of the annual equivalent dose of radon gas are also carried out. The results show that the highest concentration of radon gas is in Charcoal Facial SCRuB (American origin) and it is equal to 0.0795 Bq/m3, whereas the lowest one in "bb" cream basis (5 in 1) is equal to 0.0355 Bq/m3. Based on specific international organizations and agencies, the concentration of radon in the samples under consideration is within the acceptable limits.

Characterization of a novel passive personal fast neutron dosimeter based on a CR-39 track detector in monochromatic neutron fields via Monte Carlo simulations and experiments

The response in terms of personal dose equivalent of a passive fast neutron dosimeter composed of a CR-39 detector coupled with a 1-cm-thick PMMA radiator is investigated in monochromatic neutron fields via simulations and experiments. In particular, the simulations were performed through the Monte Carlo FLUKA code (version 2011.2x.5), while the experimental fields were produced at the AMANDE facility (IRSN, France). The dosimeter response is studied with respect to both the energy and the angle of incidence of the radiation field on the device. The simulated response shows a quite stationary trend, that is, minimal variation across a wide energy range, also for different irradiation angles. The agreement between simulated and experimental responses indicates the simple and cheap dosimeter presented as promising for personal dosimetry applications in practical situations.

New Inorganic Boron Assessment in environmental Samples by Neutron Activation Analysis using CR-39 Solid State Nuclear Track Detectors.

A new trend in applying nuclear solid-state track detector CR-39 for neutron activation assessment of inorganic boron compounds in environmental samples was established. The nuclear reaction 10B(n, α)7Li was selected for this purpose by using gelatin film for a sample application. It possesses many advantages such as time saving, sensitivity, and reproduciblity, and many related variables were studied. Linearity was found at the range of 1.0 - 12.5 ppm and at 10.0 -250 ppm with different slopes. There were no interfering nuclei among the naturally abundant elements and their isotopes, viz. Al, O, Na, Cl, P, Ca, Si, K, and Cu. It was applied to determine boron in simulated environments and industrial soil and water samples, with recovery within the range of 96-100 %, good precision and accuracy + 1.5 - 3.0 %. The method sensitivity can be enhanced by using longer irradiation time, and few micrograms of boron can be analysed, and hence it is more suitable to be used in the activation analysis system of nuclear reactors.

Determination Radon Concentration (Radon Gas) in Urine of Patients with Cancer

The present study aims at studying the measurement radon concentration (Radon gas) in the urine of patients with cancer, that made up of (23) different samples of patients’ urine. These samples have collected from Kirkuk Oncology & Hematology Center. Chemical etching process for CR-39 track detector has used to record the traces of Alpha particles “alpha rays” or “alpha radiation” that comes from Radon included in the models. The Plastic Tubing – Tubes that contain some models in reagent irradiation process, which shaped as U letter, have been used. The results illustrated that the highest concentration of Radon is (8.9) Bq.m-1 in R14 model, as well as the lowest concentration of Radon is (1.5) Bq.m-1 in R4 model. The Radon levels that have been measured are within the natural limits of radioactive decay caused by radioactive nuclide or “radioactive isotope” in urine of patients with cancer; these are not a risk in humanity.

A Study of The Radionuclides of The Petroleum Waste In Dora and Bijie Refineries Using (Hpge) Detector

The aim of this study is to detect the radioactivity of radionuclides and measure the specific activities and the uranium concentration in (19) samples of crude oil and oil waste were brought from two oil locations Dora refinery, Bijie refinery.
 The measurements in this study were done by using two techniques:
 1- Gamma rays spectroscopy system was used to measure the specific activity for radionuclides. This system is consist of high purity of germanium detector (HPGe) with personal computer as multi channel analyzer (MCA) that computerized to plot the radioactive spectrum and compute the specific activities of the radionuclides. There are seven radionuclides are detected:
 (Bi-214, Ra-226, TI-208, Bi-212, Pb-212, K-40, and Cs-137), these radionuclides included; two
 
 radionuclides (Bi-214,Ra-226) belong to the U-238 series, three radionuclides (TI-208, Bi-212, Pb-212) belong to Th-232series, one natural radionuclide (K-40), and one artificial radionuclide (Cs-137).
 For Dora refinery samples, the averages of specific activities of (Bi-214, Ra-226) were (7.79, 16.08) Bq/kg respectively, the averages of specific activities of (TI-208, Bi-212, Pb-212) were (7.95,4.05,5.75) Bq/kg , the average of specific activities of (Cs-137) was (0.64) Bq/kg , the average of specific activities of (K-40) was (99.3) Bq/kg.
 For Bijie refinery samples, the average of specific activities of (Bi-214) was (0.39) Bq/kg, the averages specific activities of (Bi-212, Pb-212) were (0.02,0.01) Bq/kg, the average of specific activities of (K-40) was (2.28) Bq/kg , and three radionuclides (Ra-226, TI-208, and Cs-137) were not appeared in Bijie samples.
 2- solid state nuclear track detectors technique (SSNTDs), the uranium concentration determined by using CR-39 track detector and fission fragment track technique, the nuclear reaction used as source of uranium fission fragment is U-235 (n-f) obtained by the bombardment of U-235with thermal neutrons emitted from (Am-Be) neutron source with flux (5000 n/cm2.s) for seven days, the concentration were calculated by
 comparison with the standard samples. The uranium concentration in Dora refinery samples were ranged between (0.95-3.34) ppm with average (2.03) ppm for solid samples and (1.25) ppm for liquid samples. The uranium concentration in Bijie refinery samples were ranged from (0.42-1.46) ppm with average (0.55) ppm in the solid samples and (1.24) ppm in the liquid samples, these results are agreement with the permissible limit from IAEA, the permissible limit is (1mSv/y) for the public.

Calculation of Concentration of Radon Gas in Specimen of Rivers Water samples in Diwaniya-Iraq’By Using CR-39 Track Detector

The concentration of radon gas in a specimen of water of specific areas in “Al - Diwaniya” province was calculated through employing alpha-emitters registrations, which is in’(CR-39)”nuclear track detector. The study focuses in determining the concentration of the gas in tap water specimen provided by the water grid of houses in ‘Al-Diwaniya province. The findings indicate that the radon maximum level in water’ ‘specimen was in (Alshanaafia 5) area assigned to be (0.56 ± 0.30 Bq/L), and the minimum level’ is in’(Afak 5) area around (0.165 ± 0.031Bq/L), in addition, to a rate value of (0.336 ± 0.075 Bq/L). The results also indicate that the radon gas in tap water is less than the acceptable boundary from (ICRP) organization which is (0.5994 Bq/L), but the concentrations of radon exhalation rate (RER) is about’(0.245-0.072 μSv/y) and the rate value is ‘(0.1462 ±1.23 μSv/y).

Calibration of Solid State Nuclear Track Detectors CR-39 for radon study in a high concentration underground mines

The Brazilian National Commission for Nuclear Energy (CNEN) establishes a reference level of 1000 Bq m-3 of radon concentration in underground mines. Solid State Nuclear Track Detectors – SSNTD is considered the main method of analysis in radon research. The methods and instrumentation used to determine radon concentration needs to be validated by calibration to ensure reliable results. This work aims to determine the calibration factor of CR-39 detectors exposed to well known radon concentrations produced in closed systems by sources of Ra-226 with activities of 3.379 kBq and 0.483 kBq, which are NISTS sources of activities and emanation factors. The detectors were exposed to six different levels of exposure. The conversion factor between tracks density and exposure obtained was K = 52.028 ± 0.752 [(tracks density.cm-2)/(kBq.d.m-3)]. As object of application of this work, mines were chosen with high radon concentrations reported by Santos (2015) in special a pegmatite mine located in the northwest of Minas Gerais. This mine presented radon concentration much higher than the recommended by the Brazilian national standard NN.CNEN.4.01, up to 7384 ± 517 Bq m-3.

Theoretical evaluation of calibration factor for CR-39 track detector for alpha radioactivity measurement in natural water

A simple track-etch method by using CR-39 detectors has been developed for determining the total alpha radioactivity level in natural water. The detectors are immersed into water sample for alpha exposure. Alpha particles generated near the detectors create latent tracks, which are a measure for the alpha radioactivity of the sample. Calibration factor (CF) evaluation for a track detector is a part of this method. It is evaluated by considering major alpha-emitters present in natural water and taking into account the actual geometry of the set-up. The method for evaluating the CF is based upon the calculating range of alpha particles in water and the estimating effective volume of water around the detector. The evaluated CF is found to be(116.18±9.88)Bq.l−1.(tracks.cm−2.h−1)−1. This method has been used to determine the total alpha radioactivity of 52 drinking water samples collected from different tube-well and tap water points at eight districts of Indian state of West Bengal. Measured radioactivity values vary from (15.17±1.29)Bq.l−1 to (45.67±3.88)Bq.l−1 with a mean value of (27.64±2.35)Bq.l−1. These radioactivity values are compared well with the worldwide alpha activity values reported in research articles. It is observed that the measured alpha radioactivities are below the recommended reference level and hence, the drinking waters of the sampling sites are safe for consumers. The CF evaluated and the experimental method developed in the present study can also be utilized in the radioactivity research field. Data obtained in the present study may serve as a good baseline.

Measurement of uranium concentrations in tap water samples collected from Muthanna governorate, Iraq using nuclear track detector CR-39

In the current study, uranium concentrations were measured in tap water samples collected from selected regions in Muthanna governorate southern Iraq. Fission track analysis technique with alpha track detector (CR-39) has been applied to determine the uranium content. The results of this experimental investigation showed that the highest value of uranium concentration in tap water samples was 4.05 ± 0.16 μg/l found in Al-Hassan district, while the lowest value was 2.02 ± 0.13 μg/l found in Al-Mualimin district. The average value of uranium content in tap water samples was 3.01 ± 0.15 μg/l. The results of the uranium content were compared with the published data and they were found to be within the safety levels.

Investigation of Neutron Generation upon Irradiation of Deuterated Crystalline Structures with an Electron Beam

The possibility of neutron generation by irradiating deuterated crystalline structures with an electron beam with an energy of 20–40 keV was studied. As targets, the deuterated crystalline structures of palladium and textured CVD diamond were used. Measurements of neutron emission are presented, which were carried out by three independent methods—scintillation detectors, counters based on He-3, and track detectors CR-39.The average neutron flux during irradiation was estimated as 1–10 s $${}^{-1}$$ in 4 $$\pi$$ sr.

Estimating the Concentrations of Radioactive Radon Element along with the Radiation Risk Indicators at the Oncology and Nuclear Medicine Hospital in Mosul, Iraq

The radioactive radon concentration was determined in addition to the radiation risk indicators represented by the effective annual dose and the effective alpha energy concentration, as well as the lung cancer cases per year at selected and different well-ventilated sites in the Oncology and NuclearMedicineHospital in Mosul. The long-term cumulative counting technique of nuclear traces deposited on the nuclear track detector CR-39. Twenty-five sites were chosen within the hospital in its multiple buildings (administration building, laboratory building and consulting building), where these reagents were installed in the lower part inside the radiometric dose room (Dosimetry) with certain geometric dimensions for 47 days as an irradiation time Calibration was performed with a 2µci radium(222Ra) source. The results showed that the radon concentrations recorded for all sites ranged between (41.44 - 79.88 Bq.m-3) with a rate of (59.32 ± 9.08 Bq.m-3) and could be considered within the global normal levels. As for the annual effective dose (HE), as its value ranged (1.3-2.52 mSv.y-1) with a rate of (1.84 ± 0.29 mSv.y-1), while the annual effective dose values ​​ranged between (4.48-8.6 mWL) with a rate of 1.08 mWL (± 5.92, and the risk index is lung cancer). It included within the values ​​(32.52-54.34 / 106 person) and a rate of (35.16 ± 5.39 / 106person), and these indicators can be considered in light of the results obtained as falling within the normal global levels. I indicated the sites of the refrigerator of refrigerated drugs, the office of mental health and the laboratory store the highest-level Radon concentration, as well as radiation hazard indicators, while its values ​​were within the lowest levels recorded in the advisory path. The highest level of radon concentration as well as radiation risk indicators were identified at the sites of the medication refrigerator, the mental health clinic, and the laboratory store, although their values were below the lowest levels documented in the advisory corridor. The results showed that the Oncology and Nuclear Medicine Hospital is logically radio-safe, despite the fact that some of its sites reported high levels of radon concentration compared to other sites, especially when combined with appropriate global levels that do not exceed ( (200-300 Bq . m-3).

Monte Carlo Study of Imaging Plate Response to Laser-Driven Aluminum Ion Beams

We measured the response of BAS-TR imaging plate (IP) to energetic aluminum ions up to 222 MeV, and compared it with predictions from a Monte Carlo simulation code using two different IP response models. Energetic aluminum ions were produced with an intense laser pulse, and the response was evaluated from cross-calibration between CR-39 track detector and IP energy spectrometer. For the first time, we obtained the response function of the BAS-TR IP for aluminum ions with a kinetic energy as high as 222 MeV. On close examination of the two IP response models, we confirm that the exponential model fits our experimental data better. Moreover, we find that the IP sensitivity in the exponential model is nearly constant in this energy range, suggesting that the response function can be determined even with little experimental data.

Development of alpha tracks measurement with thermal oven as an etching technique for SSNTDs

Abstract In the present work, Thermal oven as a heating technique in chemical etching process has been tested to investigate the track density and compares with a traditional technique water bath (WB). Thermal oven induced chemical etching has been employed in reducing the etching duration. Two solid-state nuclear track detectors (SSNTDs) CR-39 and LR-115 are utilized in this comparison. Detectors are exposed to 226Ra alpha source (5 µ ci). Several pieces of CR-39 and LR-115 detectors were exposed to 226Ra source at three different times of exposure (5, 10 and 15sec). Chemically Etching carry out with NaOH alkaline solution (6.25 N) at 70 °C for CR-39 and (2.5 N) at 60 °C for LR-115. For (5, 10 and 15sec) exposure time, the estimated maximum track densities of CR-39 detector at 90 min for thermal oven compared with 120 min for water bath. LR-115 detector maximum track densities were founded at 40 min compared with 50 min for the water bath technique. Finally, the etching parameters (the diameter of the tracks (D), etching efficiency (ɳ), bulk etching rate (VB), track etching rate (VT), and the sensitivity (V)) were calculated and compared.

Uranium Concentrations in Urine of Maternal Samples in Baghdad Governorate

The trace concentration of uranium in urine samples for pregnant women and non- pregnant women were determined using fission track technique with CR-39 track detector that is employed for registration of induced fission tracks. A total of 32 urine samples were collected from Yarmouk Teaching Hospital, Department of Obstetrics and Gynecology for Pregnant women and 5 urine samples were collected from Different regions of Baghdad governorate. The results show that the uranium concentration in urine of Pregnant women were ranged from 0.58 μg/l (30 years old, living in AL- Shurta AL khamisa region) to 1.58 μg/l (23 years old living in AL–Doura region) with average 0.92±0.2 μg/l. While for non-Pregnant women, uranium concentration ranged from 0.61 μg/l (24 years old, living in AL-Doura region) to 1.16μg/l (40 years old, living in AL-Ghazaliya region) with average 0.874±0.19μg/l. It was found that the average uranium concentrations in urine samples for pregnant women living in Hayi AL-maealif region higher than other regions in Baghdad governorate.

تأثير الأشعة السينية X-Ray في معدلات سرعة القشط (VB وVD) لكاشف الأثر النووي CR-39

تأثير الأشعة السينية X-Ray في معدلات سرعة القشط (VB وVD) لكاشف الأثر النووي CR-39