CR-39 Nuclear Track Detectors Research Articles

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.

Addendum to “Annealing of fission fragment tracks in CR-39 nuclear track detector — Phenomenological model” [Nucl. Instrum. Methods A 940 (2019) 40–44

Addendum to “Annealing of fission fragment tracks in CR-39 nuclear track detector — Phenomenological model” [Nucl. Instrum. Methods A 940 (2019) 40–44

Validity of the diameter-length method for determining the bulk etch rate of a CR-39 detector

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.

Radon and Thoron Concentrations Measurement in Tea Samples Consumed in Iraqi Markets Using CR-39 Detector

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.

Finding Bulk etch rate VB using the maximum value of the Lmax effect using practical diameters calculated from the falling alpha particles on the CR-39 nuclear track detector

A lot of research was focused on studying the engineering shape of the impact and its development and finding its parameters. It was based on pictures of the side effects of the effects formed in the detector as a result of the detector’s etching. Obtaining pictures of the side effects of the effects to measure their lengths is a difficult process compared to its diameters. There are many methods used to find Bulk etch rate VB including gravimetric method or thickness difference; but we will use in this research an alternative method to find VB which is the maximum value method for saturation of the effect length “Lmax-method”. Using the source Am241 (1μCi) emitting alpha particles in irradiation of the PDAC CR-39 irradiation With MeV energies (2.3,3.3,4.3), the detectors etching by NaOH aqueous solution at different concentrations (N: 6,7,8) at a temperature of 70±1 °C, we suggested in our research a D-Le calibration method that is based on direct experimental measurement of the diameters of the projected effects in Detector instead of lengths. An empirical relationship was used to find VB, which depends on the maximum values of saturation of effects lengths and their saturation times. The results we obtained for VB values at the concentrations used were (1.199,1.490,2.184) μm h−1 in order and they correspond well to the values resulting from different methods, it is observed The Bulk etch rate increases with the concentration of the abrasive solution, and the maximum values of saturation of the effect length are directly proportional to the energy of the bombing particles and the time of saturation of the impact lengths.

Radon concentration in conventional and new energy efficient multi-storey apartment houses: results of survey in four Russian cities

During last decades, energy saving in new buildings became relevant within the energy efficiency strategies in various countries. Such energy efficient building characteristics as air tightening and low ventilation can compromise indoor air quality, in particular, increase radon concentration. In Russia, a significant part of the new buildings is the energy efficient multi-storey apartment houses. The aim of this study is to assess the significance of possible radon concentration increase in new energy efficient buildings in comparison with typical conventional multi-storey houses of previous periods. Radon surveys were conducted in Russian cities Ekaterinburg, Chelyabinsk, Saint-Petersburg and Krasnodar. The radon measurements were carried out in 478 flats using CR-39 nuclear track detectors. Energy efficiency index (EEI) was assigned to each house. All buildings were divided into six main categories. The smallest average radon concentration was observed in panel and brick houses built according to standard projects of 1970–1990 (four-city average 21 Bq/m3). The highest average radon concentration and EEI were observed in new energy efficient buildings (49 Bq/m3). The trend of radon increase in buildings ranked with high EEI index is observed in all cities. The potential increase of radiation exposure in energy-efficient buildings should be analyzed taking into account the principles of radiological protection.

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

Investigate Oblique Incident Alpha Particle Tracks on CR-39 Detector

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

Bulk etch rates of CR-39 nuclear track detectors over a wide range of etchant (NaOH aqueous solution + ethanol) concentrations: measurements and modeling

Bulk etch rates for CR-39 detector were measured and studied over a wide range of NaOH aqueous solution concentrations (2–20 N) with different ethanol volumes. This wide range of etching concentration is divided into two major parts: soft etching part (2–8 N NaOH) and dense etching part (8–20 N NaOH). This classification will be explained and discussed. The etchant viscosity in the two parts was measured and compared. The effect of ethanol in both parts was deduced through a new parameter called ‘reduced bulk etch rate’. This new parameter helps in analyzing the dependence of bulk etching on the amount of ethanol in the etchant. It was found that conducting the etching process in the dense etching part reduces the etching time significantly. Etching in the dense part is not far away from equilibrium where Mushtaq, Multi-hit and Arrhenius fitting equations are applicable. The fitting of measured bulk etching data was carried out in the soft (low), dense (high) and the whole etching concentration ranges. Generally, a good agreement was found between physical data and model calculations.

Measurement of Soil –Radon Gas in Al-Mahaweel Areas of Iraq using Nuclear Track Detector CR-39

Measurement of Soil –Radon Gas in Al-Mahaweel Areas of Iraq using Nuclear Track Detector CR-39

Primary yields of protons measured using CR-39 in laser-induced deuteron–deuteron fusion reactions

Investigating deuteron–deuteron (DD) fusion reactions in a plasma environment similar to the early stages of the Big Bang is an important topic in nuclear astrophysics. In this study, we experimentally investigated such reactions, using eight laser beams with the third harmonic impacting on a deuterated polyethylene target at the ShenGuang-II Upgrade laser facility. This work focused on the application of range-filter (RF) spectrometers, assembled from a 70 μm aluminum filter and two CR-39 nuclear track detectors, to measure the yields of primary DD-protons. Based on the track diameter calibration results of 3 MeV protons used to diagnose the tracks on the RF spectrometers, an approximate primary DD-proton yield of $$(8.5\pm 1.7)\times 10^6$$ was obtained, consistent with the yields from similar laser facilities worldwide. This indicates that the RF spectrometer is an effective way to measure primary DD-protons. However, due to the low yields of $${\hbox {D}}^{3}{\mathrm {He}}$$-protons and its small track diameter, CR-39 detectors were unable to distinguish it from the background spots. Using other accurate detectors may help to measure these rare events.

Measurement of cross sections for charge pickup by $$^{\textbf {{84}}}\textbf {Kr}$$ on Al, C and $$\textbf{CH}_{{\textbf{2}}}$$ targets at 400 MeV/u

The nuclear charge pickup cross sections of $$^{84}\hbox {Kr}$$ on $$\hbox {CH}_{{2}}$$, C, and Al targets are investigated using CR-39 nuclear track detector at the highest energy of 395 MeV/u. The cross sections for H are calculated from those measured on C and $$\hbox {CH}_{{2}}$$ targets. The dependence of the charge pickup cross section on target mass is studied.

Measurement of cross sections for charge pickup reaction by 56Fe on Al, C and CH2 targets at 500 MeV/n

The nuclear charge pickup cross sections of 56Fe on polyethylene (CH2), carbon and aluminum targets at an energy of 497 MeV/n were investigated using CR-39 nuclear track detector. The dependence of charge pickup cross section on target mass was studied.

Measurement of Radon Radiation Concentration in Imported and Local Powdered Milk using Nuclear Track Detector CR - 39

This study aims at measuring radon radiation in 35 different samples of local and imported powdered milk using nuclear track detector CR-39 to record the existence and impact of Alpha particles emitted from radon in the examined samples. Plastic pipes and tubes of the U type were used with the samples in radiating the detector. The study revealed that the highest concentration of radon was (1371.3) Bq.m−1 in the sample M4 (Dielac2-Dubai) and the lowest concentration is in sample M32 (Lamsa- Jordan) with a radon level (151.8) Bq.m−1. The levels of radon that were measured fall within the normal and natural concentration of the radiation that emit from the radionuclide in food and thus do not make any risk to the human life.

Assessment of Uranium in Urine Samples of Primary School Students

The environmental monitoring of radon in the children urine has been carried out by using solid state nuclear track detector CR-39. This study has been undertaken for the purpose of health risk assessments. The concentration of uranium values excreted with the boy's urine samples ranged from 0.203 Bq.L-1 (1.246 ng/L) and 2.201 Bq.L-1 (13.486 ng/L) with an average value of 0.698 Bq.L-1 (4.007 ng/L). While the concentration of uranium values excreted with the girl's urine samples ranged between 0.290 Bq.L-1 (1.777 ng/L) and 0.675 Bq.L-1 (4.135 ng/L), with an average value of 0.474 Bq.L-1 (2.901 ng/L). The amount of uranium deposited in the kidneys, according to ICRP's biokinetic model, and the annual radiation dose were also calculated. All values of the study samples were within the normal range and do not indicate any health hazard.

Concentration Of Radon In The Rain Falls In Salah-Din Province / Iraq

Five regions in Salah -Din province Iraq were chosen to the study, concentration of radon in the rainwater falls in 2016. by using long-term technique for alpha particles emission with solid state nuclear track detector (SSNTD) CR-39, which have been used to determine the above radioactive isotopes concentrations in the samples. The results show the presence of some radioactivity on the area of Bieja refinery and it was measured to be (2.606) Bq.L-1 , the min average in Balad was (1.006) Bq.L-1, in general we found that radon 222Rn concentration, in the studied water samples, was less than the allowed permitted limit which is about 18 Bq.L-1, and it has no danger on human being life.

Alpha particle detection by Makrofol® DE1-1 and CR-39 NTDs: A comparative study

In this present study, a color contrast approach was proposed to find a method for quantify uncertainty in alpha particle spectroscopy using nuclear track detectors (NTDs). According to this method, this color contrast approach was applied to NTDs as an alpha particle spectrometer. A comparison between the registration of 4.0 MeV alpha particles by Makrofol®DE1-1 and CR-39 NTDs using a color contrast method was carried out in alpha spectroscopy. The contrast of the alpha tracks of each single color channel whether red, green and blue resulting from split RGB image was determined. The measurements were proved that green color channel produced the highest contrast of the alpha tracks of about 85%, in both Makrofol® DE1-1 and CR-39 NTDs. The results of 4.0 MeV alpha particle etch-pits diameters in Makrofol® DE1-1 didn't show homogenous diameters for short etching time. The standard deviation of 4.0 MeV alpha-track diameters in Makrofol® DE1-1 went up to a maximum value of 2.23 μm at a removal thickness of 12.25 μm. When increasing the etching time, they decreased sharply to about 1.18 ± 0.02 μm at a ratio of change 0.047 that was less than 6%. The standard deviation of 4.0 MeV alpha particle etch-pit diameters in CR-39 detector was linearly correlated with the removal thickness at a ratio of change of 0.02 which was less than 5%. Results revealed that the etch-pit diameter in Makrofol® DE1-1detector, in alpha particle spectrometry was best measured around the end of the alpha particle range. Results of this study are discussed within the frame work of nuclear track formation theories and etching mechanism in nuclear track detectors (NTDs).

Simple and low cost alternative method for detecting photoneutrons produced in some radiotherapy treatments using SSNTDs

A simple and low cost alternative which is able to identify thermal and fast neutrons in a clinical environment of radiotherapy is presented. CR-39 and LR-115 Solid State Nuclear Track Detectors (SSNTDs) were used, estimating their viability. In order to register alpha tracks due to thermal neutrons, natural boric acid tablets were placed in close contact to the detector, whereas in order to detect epithermal neutrons, some were additionally covered in a thin cadmium layer. Different configurations were assembled, changing the position of the converter with respect to the detector and the incident neutron fluence, which was evaluated in different positions of a radiotherapy table. The contribution due to environmental 222Rn and its daughters to the track density registered by the detector during the measurements was found to be negligible. It is concluded that the designed experimental set up constitutes a trustworthy and affordable method to carry out neutron measurements with the recommended configurations provided for the CR-39 detector, and not with LR-115.

Theoretical and experimental study of the LR-115 detector response in a non-commercial radon monitor

B.trαcks, a simulation program for SSNTD's sensitivity, has been developed to study the response of LR-115 (cellulose nitrate) and CR-39 (poly allyl glycol carbonate) nuclear track detectors. Detectors are located inside detector holders and are used for radon measurements. The program incorporates a variety of special features gathered together to achieve good agreement between theoretical approach and experimental results. The input parameters to study the detector response are radon exposure, geometry and dimensions of a detector holder (it can be cylindrical, conical or semi-spherical), entrance type for radon gas, detector type, and V function (four different functions were selected from literature). The output results are detector response and radon progeny distribution onto internal chamber walls. In this article, the response of the LR-115, which is placed inside a non-commercial-conductive radon monitor based on diffusion chambers called G2, was theoretically and experimentally studied. The common Monte Carlo simulation procedure and an alternative approach that replicates how monitors are exposed to different radon exposures were used as theoretical approaches. Experimental methodology was conducted in a radon test chamber from Italy (MI.AM s.r.l.). Comparison results of both theoretical and experimental methodology are presented and discussed. One of the major results, among others, shows that the monitor material (conductive or non-conductive) does not influence the LR-115 response.

Measurement of the Radon Concentration and Annual Effective Dose in Malva sylvestris (Khabbaz) Plant Used in Traditional Medicine and Food

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.