CR-39 Solid-state Nuclear Track Detectors Research Articles

Range and maximum etchable track length for 93Nb ion in CR-39 detector

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.

Spatial distribution of ion emission in gas-puff z-pinches and dense plasma foci

Mega-ampere dense plasma foci and deuterium gas-puff z-pinches can accelerate deuterons to multi-MeV energies. Diagnostic measurements of the properties of these ions provide information about ion acceleration in z-pinch plasmas. In particular, the results from ion pinhole cameras seem to be useful for the discussion of ion acceleration mechanisms. Recently, we have used various configurations of ion pinhole cameras in deuterium gas-puff experiments on the GIT-12 generator at the Institute of High Current Electronics in Tomsk and on the HAWK generator at the US Naval Research Laboratory in Washington. The stack of radiochromic films and CR-39 solid-state nuclear track detectors recorded deuterons with energies up to 30 MeV. From our ion diagnostics, we obtained the spatial distribution of the ion source and the ion-beam divergence during the ion emission. This ion-beam divergence was found to decrease with increasing deuteron energy. At 20 MeV, the divergence of each of the individual micro-beams that composed the ion source was on the order of 10 mrad. The deflection of each micro-beam due to the azimuthal magnetic and/or radial electric fields resulted in radial stripes observed by the beam-profile detectors. By analyzing the ion pinhole images, we found that the deuterons were emitted both from a central spot and from a ring-shaped region with a rather large diameter, on the order of 1 cm. The origin and particular diameter of this ring is attributed to the geometry of the electrodes and to the distribution of the current density before the disruption.

High-precision angular measurement of 12C ion interaction using a new imaging method with a CR-39 detector in the energy range below 100 MeV/nucleon

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.

A new chemical etchant for the development of alpha tracks in CR-39 solid state nuclear track detector

Chemical etching is an important step for enlargement of latent tracks in solid state nuclear track detectors (SSNTD). In the etching process, bulk and track etch rates are determined by various parameters, which decide the sensitivity and efficiency of the track detector. Thus, determination of the etching parameters is essential in introducing a new chemical etchant. For the enlargement of latent tracks in CR-39, chemical etching is usually carried out at temperatures of 60–70 °C by using 6–6.5 N concentrations of alkali like NaOH or KOH. In the present work, a mixture of 8 g NaOH in 25 mL water and 25 mL ethanolamine as an etchant at 70 °C was found to be very effective in the enlargement of alpha tracks in CR-39 SSNTD. The diameters of alpha tracks resulting from this new etchant are found to be a quadratic function of the etching time, whereas those from the standard etchant are linear with respect to the etching time. This results in the reduction in the etching time by a factor of 4 with an increased etching efficiency.

Determination of Indoor Radon Concentration in Thi Qar Province Houses by using CR-39 SSNTD

The possible detrimental health effects of the inhaled radon and its decay products are in the limelight of interest of professionals as well as of the public. In the present work the passive integrated dosimeter technique with solid state nuclear track detectors (SSNTDs) super grade CR-39, was used to measure the concentration of the radioactive radon gas (Rn-222) indoor for 12 different locations in Thi Qar province. 176 detectors ( 1.0 cm x 1.0 cm x 0.5 cm) were prepared and were distributed in the chosen locations , after 90 days ( November, December 2012 and January 2013) the detectors were collected and treated chemically using etching conditions which controlled by four principals variables ( etching solutions ,temperature , morality and etching time). The tracks per unit area in each detector were determined by using MICROS Crocus II MCX100LCD optical microscope. Results obtained showed that radon average concentration indoors was varies from 25.66 Bq/m3 in Bateha to 113.63 Bq/m3 in Fuhood, and the annual effective dose according to these concentrations are 0.890 mSv/y and 3.941mSv/y respectively. Results indicate that the houses surveyed had indoor radon levels within permissible level when ICRP1993 recommended limit of 600 Bqm-3 was used. Few houses had higher radon levels if NRPB (Health Protection agency) UK and US (environmental protection agency) EPA limits of 200 and 148 Bq m-3 were used. The overall average for the concentrations of radon in indoor air in the province of Thi Qar in this study is 66.989 Bq/m3 with a standard deviation of 48.554 this concentration is less or asymptotic concentration of radon in most of the neighboring countries of Iraq.

Radon concentration measurements in sludge of oil fields in North Oil Company (N.O.C.) of Iraq

In this study the assessment radon concentration in sludge of OilFields in North Oil Company (N.O.C.) of Iraq have been studiedusing CR-39 solid–state nuclear track detector technique. A total of34 samples selected from 12 oil stations in the company have beenplaced in the dosimeters. The average radon concentration was foundto be 162.29 Bq/m3 which is fortunately lower than the standardinternational limit. The potential alpha energy concentration andannual effective dose have been calculated. A proportionalrelationship between the annual effective dose and radonconcentration within the studied region has been certified.

Approaches for Surveying Cosmic Radiation Damage in Large Populations of Arabidopsis thaliana Seeds – Antarctic Balloons and Particle Beams

Abstract The Cosmic Ray Exposure Sequencing Science (CRESS) payload system was a proof of concept experiment to assess the genomic impact of space radiation on seeds. CRESS was designed as a secondary payload for the December 2016 high-altitude, long-duration south polar balloon flight carrying the Boron and Carbon Cosmic Rays in the Upper Stratosphere (BACCUS) experiment. Investigation of the biological effects of Galactic Cosmic Radiation (GCR), particularly those of ions with High-Z and Energy (HZE), was of interest due to the genomic damage this type of radiation inflicts. The biological effects of radiation above Antarctica (ANT) were studied using Arabidopsis thaliana seeds and compared to a simulation of GCR at Brookhaven National Laboratory (BNL) and to laboratory control seeds. The CRESS payload was broadly designed to 1U CubeSat specifications (10 cm × 10 cm × 10 cm, ≤1.33 kg), maintained 1 atm internal pressure, and carried an internal cargo of 580,000 seeds and twelve CR-39 Solid-State Nuclear Track Detectors (SSNTDs). Exposed BNL and ANT M0 seeds showed significantly reduced germination rates and elevated somatic mutation rates when compared to non-irradiated controls, with the BNL mutation rate also being higher than that of ANT. Genomic DNA from plants presenting distinct aberrant phenotypes was evaluated with whole-genome sequencing using PacBio SMRT technology, which revealed an array of structural genome variants in the M0 and M1 plants. This study was the first whole-genome characterization of space-irradiated seeds and demonstrated both the efficiency and efficacy of Antarctic long-duration balloons for the study of space radiation effects on eukaryote genomes.

Estimate Level of Radon Concentration for Drinking Water in Some Regions of Baghdad City

In this study, the assessment of radon concentration in drinking water in some regions of Baghdad city in Iraq has been studied using CR-39 solid-state nuclear track detector technique. A total of 18 samples selected from 6 region (5 samples from each region) in Baghdad city have been placed in the dosimeters for 50 day. The average radon concentration was found to be 516.1 hbox { Bq/m}^{3} which is greater than the standard international limit (300 hbox { Bq/m}^{3}). The potential alpha energy concentration and annual effective dose have been calculated. A proportional relationship between the annual effective dose and radon concentration within the studied region has been certified.

Time-resolved characteristics of deuteron-beam generated by plasma focus discharge.

The plasma focus device discussed herein is a Z-pinch pulsed-plasma arrangement. In this, the plasma is heated and compressed into a cylindrical column, producing a typical density of > 1025 particles/m3 and a temperature of (1–3) × 107 oC. The plasma focus has been widely investigated as a radiation source, including as ion-beams, electron-beams and as a source of x-ray and neutron production, providing considerable scope for use in a variety of technological situations. Thus said, the nature of the radiation emission depends on the dynamics of the plasma pinch. In this study of the characteristics of deuteron-beam emission, in terms of energy, fluence and angular distribution were analyzed. The 2.7 kJ plasma focus discharge has been made to operate at a pressure of less than 1 mbar rather than at its more conventional operating pressure of a few mbar. Faraday cup were used to determine deuteron-beam energy and deuteron-beam fluence per shot while CR-39 solid-state nuclear track detectors were employed in studying the angular distribution of deuteron emission. Beam energy and deuteron-beam fluence per shot have been found to be pressure dependent. The largest value of average deuteron energy measured for present conditions was found to be (52 ± 7) keV, while the deuteron-beam fluence per shot was of the order of 1015 ions/m2 when operated at a pressure of 0.2 mbar. The deuteron-beam emission is in the forward direction and is observed to be highly anisotropic.

Directional Track Selection Technique in CR39 SSNTD for lowyield reaction experiments

There is a great interest in the study of p-11B aneutronic nuclear fusion reactions, both for energy production and for determination of fusion cross-sections at low energies. In this context we performed experiments at CELIA in which energetic protons, accelerated by the laser ECLIPSE, were directed toward a solid Boron target. Because of the small cross-sections at these energies the number of expected reactions is low. CR39 Solid-State Nuclear Track Detectors (SSNTD) were used to detect the alpha particles produced. Because of the low expected yield, it is difficult to discriminate the tracks due to true fusion products from those due to natural background in the CR39. To this purpose we developed a methodology of particle recognition according to their direction with respect to the detector normal, able to determine the position of their source. We applied this to the specific experiment geometry, so to select from all the tracks those due to particles coming from the region of interaction between accelerated protons and solid boron target. This technique can be of great help on the analysis of SSNTD in experiments with low yield reactions, but can be also generally applied to any experiment where particles reach the track detector with known directions, and for example to improve the detection limit of particle spectrometers using CR39.

Mapping of indoor radon survey and dose estimations in health centres in Turkey

Radon and its short-lived daughter products, leading to lung cancer, are the most significant contribution to the exposure of man to ionizing radiation from natural sources. Therefore, the present study aimed to assess indoor radon measurements in 39 rooms of 15 health centres in Osmaniye city, Turkey using CR-39 solid-state nuclear track detectors based on radon dosimeters. Indoor radon concentrations were found to change from 8 to 108 Bq·m−3. The associated radiological parameters such as the annual effective dose and excess lifetime cancer risk were computed for staff/patient in the rooms surveyed. The mean annual effective dose and excess lifetime cancer risk values were estimated to be 0.29 mSv and 1.02 × 10−3, respectively. The annual computed effective doses are lower than the suggested action level (3–10 mSv·y−1). Also, with ordinary Kriging method, by using R programing language and quantum geographic information system, indoor radon concentration, annual effective dose, and excess lifetime cancer risk interpolated values were recorded and mapped. The findings obtained in the current study concerning radon levels and their variations will provide baseline values for future research surveys.

고체비적검출기를 이용한 500 MeV/u 철 이온의 선에너지전이 교정

In this study, LET (Linear Energy Transfer) calibration of CR-39 SSNTD (Solid State Nuclear Track Detector) was performed using 500 MeV/u Fe heavy ions in HIMAC (Heavy Ion Medical Accelerator) for high LET radiation dosimetry. The irradiated CR-39 SSNDT were etched according JAXA (Japan Aerospace Exploration Agency) etching conditions. And the etched SSNTD were analyzed by using Image J. Determined dose-mean lineal energy () of 500 MeV/u Fe is about 283.3 keV/um by using the CR-39 SSNTD. This value is very similar result compare to the results calculated by GEANT4 Monte Carlo simulation and measured with TEPC active radiation detector. We confirmed that the CR-39 SSNTD was useful for high LET radiation dosimetry such as heavy iron ions.

Radon concentration Measurements in Qaysare of Erbil City

In this study the assessment of indoor radon concentration in the air of Qaysare in Erbil city have been studied by using CR-39 Solid–State Nuclear Track Detector Technique. A total of 18 selected zones inside the suq have been selected to place the dosimeters. The average radon concentration was found to be 21.54 ± 8.017 Bq/m3 ,which is fortunately lower than the standard international limit from 200-600 Bq/m3 as recommended by ICRP, IAEA. The potential alpha energy concentration and annual effective dose have been calculated. A proportional relationship between the annual effective dose and radon concentration within the studied region has been certified.

Radon Concentrations and Effective Radium Contents in Local and Imported Phosphate Fertilizers, Saudi Arabia

Radon concentrations and effective radium contents were measured using CR-39 solid-state nuclear track detectors. In this study, 27 local and imported phosphate fertilizer samples (liquid and solid) were collected from markets in eastern Saudi Arabia. The radon concentrations were found to vary from 3.23 ± 1.2 to 1547 ± 162 Bq m−3. The radon exhalation rates and effective radium contents ranged from 1.77 ± 0.7 to 848 ± 89 mBq m−2h−1 and from 3.53 ± 1.1 to 2246 ± 236 Bq m−3, respectively. The highest annual effective dose was from a local fertilizer sample (39 ± 9.8 mSv y−1); this value was higher than the world allowed dose. Therefore, these fertilizers can be a significant source of radiological hazards to human health. Strong correlations were found between the radon concentrations, exhalation rates and annual effective doses from the local and imported phosphate fertilizers. The radon concentrations in all fertilizer samples were compared with the recommended value from ICRP (200 Bq m−3).

Estimation of photoneutron intensities around radiotherapy linear accelerator 23-MV photon beam

CR-39 solid-state nuclear track detectors (SSNTDs) were used to study the variations of fast neutron relative intensities around a high-energy (23MV) linear accelerator (Varian 21EX) photon beam. The variations were determined on the patient plane at 0, 50, 100, 150 and 200cm from the isocenter of the photon beam. In addition, photoneutron intensities and distributions at isocenter level with field size of 40×40cm2 at Source Axis Distance (SAD)=100cm around 23MV photon beam were also determined. The results showed that the photoneutron intensities decreased rapidly by increasing the distance from the center of the x-ray beam towards the periphery, for the open fields.

First step of indoor thoron mapping of Kosovo and Metohija.

The survey of natural radioactivity in Kosovo and Metohija involves 180 indoor (220)Rn measurements. They were performed either in living rooms or in bedrooms of 127 individual, rural type houses, using a passive method with application of CR-39 solid-state nuclear track detectors. Detectors were deployed at a distance of >10 cm from the walls. Values of all 180 measurements for 127 houses give an arithmetic mean (AM) of 132 Bq m(-3). The data for indoor thoron mapping arranged within 10 km × 10 km grid cells give an AM of 118 Bq m(-3) over AM grid cells. The distribution over individual data and the grid cells can be described as normal. About 19 % of the area of Kosovo and Metohija was covered by mapping. This study includes statistical analysis and discussion of factors, such as geogenic and seasonal, which possibly affect thoron concentration, as well as comparison with simultaneous radon measurements.

Determination of Indoor Radon Concentration in Thi Qar Province Houses by using CR-39 SSNTD

The possible detrimental health effects of the inhaled radon and its decay products are in the limelight of interest of professionals as well as of the public. In the present work the passive integrated dosimeter technique with solid state nuclear track detectors (SSNTDs) super grade CR-39, was used to measure the concentration of the radioactive radon gas (Rn-222) indoor for 12 different locations in Thi Qar province. 176 detectors ( 1.0 cm x 1.0 cm x 0.5 cm) were prepared and were distributed in the chosen locations , after 90 days ( November, December 2012 and January 2013) the detectors were collected and treated chemically using etching conditions which controlled by four principals variables ( etching solutions ,temperature , morality and etching time). The tracks per unit area in each detector were determined by using MICROS Crocus II MCX100LCD optical microscope. Results obtained showed that radon average concentration indoors was varies from 25.66 Bq/m3 in Bateha to 113.63 Bq/m3 in Fuhood, and the annual effective dose according to these concentrations are 0.890 mSv/y and 3.941mSv/y respectively. Results indicate that the houses surveyed had indoor radon levels within permissible level when ICRP1993 recommended limit of 600 Bqm-3 was used. Few houses had higher radon levels if NRPB (Health Protection agency) UK and US (environmental protection agency) EPA limits of 200 and 148 Bq m-3 were used. The overall average for the concentrations of radon in indoor air in the province of Thi Qar in this study is 66.989 Bq/m3 .

Fine phantom image from laser-induced proton radiography with a spatial resolution of several μm

The advantages of a laser-driven proton acceleration have prompted studies of laser-induced proton radiography. As the CR-39 solid-state nuclear-track detector is suitable for measuring charged particles and can be used in proton radiography, we studied laser-induced proton radiography with the CR-39 for several years, and we were able to obtain a spatial resolution of about 10 μm. For obtaining an image with a spatial resolution of a few μm, we investigated the effect of the CR-39 etching conditions on the spatial resolution and carried out imaging experiments using fine phantoms. Experiments were performed using the 100-TW titanium-sapphire laser system at the Advanced Photonics Research Institute of the Gwangju Institute of Science Technology. We have demonstrated that images with a spatial resolution of about several μm can be achieved using laser-induced proton radiography.

Empirical assessment of the detection efficiency of CR-39 at high proton fluence and a compact, proton detector for high-fluence applications.

CR-39 solid-state nuclear track detectors are widely used in physics and in many inertial confinement fusion (ICF) experiments, and under ideal conditions these detectors have 100% detection efficiency for ∼0.5-8 MeV protons. When the fluence of incident particles becomes too high, overlap of particle tracks leads to under-counting at typical processing conditions (5 h etch in 6N NaOH at 80 °C). Short etch times required to avoid overlap can cause under-counting as well, as tracks are not fully developed. Experiments have determined the minimum etch times for 100% detection of 1.7-4.3-MeV protons and established that for 2.4-MeV protons, relevant for detection of DD protons, the maximum fluence that can be detected using normal processing techniques is ≲3 × 10(6) cm(-2). A CR-39-based proton detector has been developed to mitigate issues related to high particle fluences on ICF facilities. Using a pinhole and scattering foil several mm in front of the CR-39, proton fluences at the CR-39 are reduced by more than a factor of ∼50, increasing the operating yield upper limit by a comparable amount.

Real-time single-ion hit position detecting system for cell irradiation

We have developed a real-time single-ion hit position detecting system to replace a CR-39 solid-state nuclear-track detector for cell irradiation experiments because the CR-39 takes several minutes for off-line etching. The new real-time system consists of a 500-μm-thick CaF2(Eu) scintillator, an optical microscope with a 10× objective lens, and a high-gain charge-coupled device camera. Each of the 260-MeV neon ions passing through a 100-μm-thick CR-39 sheet was detected using the real-time system in a performance test for the spatial resolution. The full width at half maxima (FWHMs) of the distances between positions detected by the real-time system and the centers of the etch pits on CR-39 were 6.5 and 6.9μm in the x and y directions, respectively. The result shows that the system is useful for typical cultured cells of a few tens of micrometers in size.