Bulk Etch Rate Research Articles

Direct and indirect determination of track etch parameters after sequential UV-C exposure and etching for two swift heavy ions in PADC: Production of rocket-shaped tracks

The present work aimed to study the effect of single-sided UV-C successive exposures and sequential chemical etching on the different track parameters of bulk etch rate, Vb, detector diameter, D, detector length, L, track etch rate, Vt, detection sensitivity, and etched track shape. For this, PADC detectors initially irradiated with high energy-long range ions of 7 GeV Si and 17.48 GeV Ni were used. Fission fragment irradiations were also performed before UV-C exposure to determine the PADC bulk etch rate in exposed and non-exposed UV-C sides. Track parameters of bulk etch rate, Vb, detector diameter, D, detector length, L, track etch rate, Vt, and corresponding sensitivity were determined and compared on both sides. The relative differences between the track parameters on both sides are thus determined. It was found that exposure of PADC detectors to sequential UV-C followed by etching gives a strong increase in the two etching rates, Vb and Vt. Sensitivity measurements indicate that the rate of increase of Vb is greater than that of Vt. Track parameters data by direct track cone length and indirect track diameter versus depth evidence the existence of two regions under the polymer surface. These two regions were attributed to the polymer crosslinking and degradation processes resulting from exposure to UV-C. Region 1 and Region 2 have different etching rates. Region 1 has a constant rate, while Region 2 has an increasing rate as it goes deeper. Sequential UV-C followed by etching makes it possible to generate unusual rocket-shaped (or amphora-shaped) tracks. One possible application of the described technique is the production of nuclear track membranes.

The Etching Effect Methods in Registration Properties on CR-39 Nuclear Track Detector

In this work, we use three different etching techniques—water bath, microwaves, and hotplate stirrer devices—in an effort to confirm the optimal etching time and conditions for tracks in the CR-39 solid-state nuclear track detector following irradiation to an alpha particle source (241Am). The research shows that the water bath’s maximum track density is 57596 tracks/cm2, appearing at 90 and 150 minutes. On the other hand, the hotplate stirrer’s maximum track density is 28050 tracks/cm2, appearing at 90 and 150 minutes. The microwave is the best etching method since it generated the tracks (65076 tracks/cm2) in a relatively short amount of time (10 min). The computation of the etching parameters, which are the bulk etch rates (VB), track etch rate (VT) and track etch ratio (V), was investigate in the etching properties. The time for the appearance of all traces of the microwave device is at a time of 10 minutes, followed by a hotplate stirrer at a time of 90 minutes, then a water bath at a time of 120 minutes.

Molten Ba(OH)2.8H2O as an efficient and rapid etchant for detecting α-particles using a diallyl maleate-allyl diglycol carbonate detector

In the present study, for the first time, nuclear tracks of α-particles were created on diallyl maleate-allyl diglycol carbonate (DAM-ADC) using molten hydrated barium hydroxide (MBH). We used 17 DAM-ADC plates with dimensions of 1.0 cm × 1.0 cm × 0.1 cm. The bulk etching rate was calculated at various etching temperatures based on changes in the thickness of the DAM-ADC plates. DAM-ADC was irradiated with α-particles to etch at various temperatures for different durations in order to determine the characteristic etching parameters, such as the bulk and track etching rates, etching efficiency of the detector, and critical angle of etching. Photographs of the etched DAM-ADC samples were obtained with a calibrated optical microscope and analyzed with ImageJ software to calculate the track diameters of α-particles. The results demonstrated that MBH is a more efficient and rapid etchant for registering and detecting charged particles with various energies compared with conventional etching solutions (NaOH, KOH, etc.). DAM-ADC with MBH can be used in environmental applications for detecting radon and neutrons.

Study on the preparation of porous polyethylene glycol terephthalate film and the influencing factors of etching rate

AbstractPorous polyethylene glycol terephthalate (PET) film is a kind of mesopore structure template with pore size ranging from nanometer to micrometer by chemical etching after irradiation of heavy ions. The etching rate is an important factor affecting the pore morphology and quality of the membrane. In this paper, four stacked PET film were irradiated with 140 MeV 32S ions at room temperature and vacuum. During chemical etching of irradiated samples, the path etching rate Vt was determined by conduction method, and the bulk etching rate Vb was determined by weighing method. The relationship between etching temperature, concentration, sensitization time, and etching rate was studied. The results show that the etching rate is exponentially correlated with the etching temperature, and increases linearly with the increase of the etching solution concentration. When the concentration of NaOH is 3 mol·L−1 and the etching temperature is 75°C, the formation of cylindrical micropores is the most favorable. The pore size of porous PET film can be adjusted, and the relationship between pore size and etching time is . This is of great significance for the preparation of nanowires with uniform size and stable properties.Highlights We have obtained the optimal conditions for obtaining cylindrical holes. The relationship between the diameter of holes and etching time were determined.

Time-efficient etching of LR-115 SSNTD film for indoor radon, thoron quantification.

LR-115 Solid State Nuclear Track Detector (SSNTD) is commonly utilized for quantifying indoor radon-thoron levels, by tallying the tracks formed in the films by exposure to these gases. Conventionally, sodium hydroxide (NaOH) is used to etch LR-115 films for 90 min at 60°C. However, this study suggests a time-efficient alternative approach utilizing potassium hydroxide (KOH) as the etchant. In an initial investigation, the bulk etch rates of KOH were examined at different normalities and temperatures, revealing that KOH exhibited nearly double the bulk etch rates compared to NaOH. Subsequently, a specially designed controlled experiment was conducted to assess the efficacy of the technique by enumerating the tracks generated in the films. Both etchants demonstrated very similar track counts for identical controlled exposures, indicating the reliability of the method. A consistent behavior was observed in the real-case scenario of LR-115 films exposed indoors to alpha particles from radon and its decay products. In both experiments, the etching with KOH for 45 min gave track densities comparable to standard NaOH etching for 90 min, highlighting the time efficiency of this method. Investigations were carried out into track shape and size features, aspects crucial to the measurement technique, using microscopic imaging of samples treated with both etchants. Strikingly similar track shapes and sizes were observed, affirming the consistency in the track measurement technique. Collectively, these findings suggest that KOH etchant reduces the etching time, presenting itself as a time-efficient method for quantifying radon and thoron track density.

Studies on pre-irradiation thermal annealing induced new phase formation in a PADC polymer: The influence of phase transition on heavy ion detection

Stimulation with thermal pulses can realize and manipulate states of matter with emergent structural and electronic phenomena. The transition phases are often non-transient, and the challenge is to understand them as persistent states. Isochronal annealing experiment at annealing temperatures of 130, 140, 150 and 160 °C for 8 h, was conducted on PADC (so-called CR-39) detectors prior to their irradiation to 252Cf source. Reversing the sequence, other detector films were first subjected to 252Cf irradiation and then thermally treated only at 130 °C for 8 h as above. for example, as a standard comparison between both processes: irradiation post-annealing and irradiation pre-annealing. The bulk etch rates were measured by using the weight loss method (WLM) and the fission track diameter method (FTDM). The qualitative impacts of these treatments have been characterized by means of X-ray diffraction, differential scanning calorimetric (DSC) and spectroscopic measurements of FT-IR. Specifically, the dependences of structural, thermal and chemical parameters on the thermal pulses passed through PADC polymer films treated at different annealing temperatures for annealing time 8 h have been measured. The phase transition of the PADC films was found to be dependent on the annealing temperature, in addition, phase transition proved to be clearly formed by increasing the annealing temperature at 130 °C. This paper shows how the well-controlled thermal treatment of the PADC detector can alter its radiation detection thresholds and its detection sensitivity in the near-surface layer of thickness beyond a couple of hundreds of nanometers. This finding is more pronounced for cases of higher annealing temperatures and larger annealing time intervals. The obtained results demonstrate that the heavy ions (with higher ionization rates e.g., fission fragments), are clearly detected in the near-surface layer of the thermally treated PADC.

Experimental and simulated etched track profiles for two relativistic ions treated under different etching conditions: How to shape different track envelopes

PADC polymer sheets of thickness 650 μm were exposed to normal incident high energy ions of 7 GeV Si and 17.48 GeV Ni with particle density ≈ 103 particles/cm2. Chemical etching was carried out under soft and strong etching conditions, and parameters of track diameter and cone length variation with depths were measured and recorded at successive times during the etching process, including snapshots of the etched track profiles. A computer program using a sophisticated chemical etching model including a variation of the bulk etching rate of the detector material was used. This program uses experimental data of a variable bulk etch rate with depth (Vb (z)) and an average longitudinal (Vt) etching rate, for each etching condition and ion. A good agreement is obtained between simulation and experiment in all cases, which validates the choice of the model used and the constant Vt approximation. It is shown that the same latent track due to a given ion gives different three-dimensional shapes depending on the chemical etching conditions used. The production of etched tracks with funnel shapes is one of the originalities of this work. The simulation tool developed allows for exploring the production of microcavities with specific shapes using polymer sheets exposed to high-energy ions.

Efficient and fast detection of alpha particles using CR-39 detector

The CR-39 track detector was used to create alpha particle tracks using molten hydrated barium hydroxide (MBH). In this experiment, seventeen CR-39 plates with a thickness of 250 μm were used. For determining the bulk etch rate, the rate of the change of track dimeter of fission fragments has been used. The detectors were etched at the suitable etching conditions of MBH, and the track diameters were measured using two suitable image analysis software (Infinity Analyzer and ImageJ). A standard micrometer slit was used to calibrate the images in the field of view of the microscope. The results of this investigation demonstrated that MBH provides significant etching characteristics in addition to shorter etching times and higher etching efficiency for the registration and detection of charged particles of various energies. This work has numerous uses, ranging from plastic nuclear track filters and environmental applications to alpha spectroscopy and neutron detection. Results of sample irradiation, track diameter analysis, sensitivity analysis, and etching efficiency analysis are covered in detail.

Effect the Annealing on The Growth Length Rate of Alpha Particles Tracks in CR-39 Nuclear Track Detector

The aime of this paper is to investigate the impact of annealing on track growth rate (dL/dt), which is calculated using the track length measurement method. A 600 micro meter-thick CR-39 detector, divided into four samples (1 x 1 cm2), was vertically irradiated by alpha particles with 2.6 MeV from a 241Am source which have max energy 5.48 MeV . The three samples were annealed at 100–140oC by type 20o C using oven Memmert U4079142. All samples were etched in a 6.25 N NaOH solution at 70±1 oC in a Memmert W200 water bath, the periodic etching time was 0.5 hours to 6 hours. The etched image was captured using a camera (MADC_5A) attached to a microscope (XSZ-H Series Biological Microscope). The bulk etch rate and diameters increase with increasing annealing temperatures. The new method used in this paper to calculate the experimental track length is based on the relation between track length and track diameter obtained from track-test software.

Sensitivity reduction and track parameters fading of PADC irradiated to high energy ions after twenty-seven years

PADC track etching parameters measured in 1994 and 2021 were compared. Track fading over the longest time (27 years) was determined. The etching conditions of the samples were reproduced as closely as possible, namely 6.25M NaOH and 50 °C. The difference in track parameters of diameter, bulk, track etch rate, and detector sensitivity with detector depth for 1.89 GeV N, 0.96 GeV C, 19.2 GeV Ar, 46.48 GeV Fe, and 17.7 GeV Ni have been measured. Track diameter growth with etching time, te was observed for N, C, Ar, Fe, and Ni tracks and compared with 1994 data. Clear larger bulk and track etch rates have been observed for the current measurements compared to the previous ones for the 5 ions under investigation. A significant reduction in PADC sensitivity due to fading was observed after these twenty-seven years. The higher the ion's LET, the more the fading. The reduction rate was calculated, and a sensitivity correction formula was introduced. Detector sensitivity at any previous time can be calculated from the current sensitivity by the suggested equation. The physical and chemical explanations for the fading changes in different track parameters were suggested.

Comparative study on traditional and new etchants for radon monitoring using Poly(allyl diglycol carbonate) (PADC) and identification of (Na3H(CO3)2.2H2O) in etched products

A comparative study is conducted on Traditional Etchants (NaOH/H2O, KOH/H2O) and New Etchants viz. NaOH/Methanol, NaOH/Ethanol and NaOH/1-propanol for Poly(allyl diglycol carbonate) (PADC) used in Radon monitoring. Molar concentration of traditional etchants NaOH/H2O and KOH/H2O is varied from 1 M to 6 M and etching temperature is varied from 30 °C to 80 °C to verify optimal etching parameter. Etching is done for 8 to 9.5 h in the steps of 30 min. An average bulk etch rate (Vb) of 1.4μm/h and 1.7μm/h for NaOH/H2O and KOH/H2O is calculated respectively under optimal etching conditions. Optimal reported concentrations of 1.5 M, 1.5 M and 1 M respectively, are used to make standard NaOH/Methanol, NaOH/Ethanol and NaOH/1-propanol solutions. Track densities, track diameters, bulk etch rate (Vb), track etch rate (Vt), etching time, variation in mass and thickness for both traditional and new etchants are calculated and compared. Traditional etchants take much longer time (5 to 7 h) for etching with initial swelling due to absorption of etchant on the surface of detector due to broken molecular chains, causing increase in mass and thickness of detectors for initial 0.5 to 1 h of etching which are measured with digital balance (±0.0001 g) and digital micrometer (±0.001 mm) respectively. New etchants take short time for etching (30 min approx.). There is no initial increase in mass and thickness of detectors due to short etching time and high Vb of new etchant. Traditional etchants give high track densities with low Vb and Vt while new etchants gives low track density with high Vb and Vt. New tracks formation is rare in new etchants as compared to traditional etchants. An average radon concentration level of 21.8 kBqm−3 is calculated from detectors etched in traditional etchants while new etchants do not provide any useful information about radon track density to calculate radon concentration for the given samples. Trona i-e Na3H(CO3)2.2H2O is identified as a common product formed in the etched products of PADC etched in either of the etchants i.e. traditional etchants and new etchants, using X-ray powder diffraction (XRPD) analysis.

Ultrathin, High-Lifetime Silicon Nitride Membranes for Nanopore Sensing.

Thin membranes are highly sought-after for nanopore-based single-molecule sensing, and fabrication of such membranes becomes challenging in the ≲10 nm thickness regime where a plethora of useful molecule information can be acquired by nanopore sensing. In this work, we present a scalable and controllable method to fabricate silicon nitride (SixNy) membranes with effective thickness down to ∼1.5 nm using standard silicon processing and chemical etching using hydrofluoric acid (HF). Nanopores were fabricated using the controlled breakdown method with estimated pore diameters down to ∼1.8 nm yielding events >500,000 and >1,800,000 from dsDNA and bovine serum albumin (BSA) protein, respectively, demonstrating the high-performance and extended lifetime of the pores fabricated through our membranes. We used two different compositions of SixNy for membrane fabrication (near-stoichiometric and silicon-rich SixNy) and compared them against commercial membranes. The final thicknesses of the membranes were measured using ellipsometry and were in good agreement with the values calculated from the bulk etch rates and DNA translocation characteristics. The stoichiometry and the density of the membrane layers were characterized with Rutherford backscattering spectrometry while the nanopores were characterized using pH-conductance, conductivity-conductance, and power spectral density (PSD) graphs.

Determined the bulk etch rate VB by different methods for nuclear track detector CR-39

In this study, the bulk etch rate (VB) was measured by three different methods forCR-39 with a thickness of 200µm and an area of (1 × 1 cm2), where CR_39 was irradiated through from Am241source with energy of alpha particles is 2.6MeV and at an angle of fall perpendicular to the surface of the CR-39 detector, the detector etching with (NaOH) at a concentration of 6.25N and (70 ± 1°C) and showing the effects formed on the surface of the detector with time periods ranging from (0.25h) and the formed effects were photographed In the detector at different eching times using an optical microscope of the type (XSZ-H Series Biological Microscope) equipped with a digital camera of the type (MADC_5A) connected to a personal computer, in order to find the length, thickness and diameters of the track formed on the surface of the detector.VB determind by methods are: Removed thickness method, the second method, the saturation track method, and the diameter-length method (D_L method), as the first method does not require irradiation of the detector, but the other two methods require irradiation of the detector and measurement of lengths and diameters And the time of proving the effect, and we found that the values of VB rate for the three methods, the removed thickness method, the saturation track method, and the diameter-length of the effect ((D_L method) respectively are:, (1.206, 1.204, 1.271 (µm/h) and compare the results between the mentioned methods, as we found that they are close.

Variation of the Bulk Etch Rate of Nuclear Track Detector CR-39 With the Chemical Etchant Solution Normality

The variation of the bulk etch rate (VB) of nuclear track detector CR-39 with the normality of the chemical etchant were studied. The removal thickness measurement method is used to determine the bulk etch rate. the detectors were etched by an aqueous solution of NaOH with normalities (4, 5, 6, 7) N at temperature (70±1) oC. It was found that the bulk etch rate is exponentially increasing with the normality of the solution and its values are (0.687, 1.421, 0.954, 2.082) µm/h at normalities (4, 5, 6, 7) N respectively. the relation between the bulk etch rate and the etchant normality was an exponential relation and the results showed good agreement with the results of the others used other normalities and another measurement method. 

A Study on the Bulk Etch Rate of LR-115 Solid State Nuclear Track Detector using Lithium Hydroxide as an Etching Solution

A Study on the Bulk Etch Rate of LR-115 Solid State Nuclear Track Detector using Lithium Hydroxide as an Etching Solution

Extended dose response of 10B+CR-39 for thermal neutrons using spectrophotometric techniques

In this work, measurements were carried out in a standard thermal neutron facility using CR-39 detector combined with boron converter to study the dose response of CR-39 for thermal neutrons and the implementation of spectrophotometric techniques to extend the response towards high dose equivalents. The dose dependent variations in the response of 10B+CR-39 detectors versus etching and track parameters, structural and optical parameters were studied by image analysis, FTIR and UV–Vis spectral analysis. The track density increased linearly with the thermal neutron dose equivalent up to 0.46 mSv with a sensitivity of 7.393 × 105 tracks cm−2 mSv−1, above which saturation effect was observed. The bulk etch rate increased with the dose equivalent up to 4.761 mSv, beyond which it was found to be saturated. From FTIR spectral analysis, the absorbance peak intensities decreased with the neutron dose equivalent up to 4.761 mSv and saturation effects were observed above it. Similar result was also obtained from the UV–Vis spectral analysis, thereby demonstrating its application for thermal neutron dosimetry up to 4.761 mSv. Accordingly, the empirical relations were derived for dose estimation up to 4.761 mSv. From the Tauc analysis, the optical band gap for both direct and indirect transactions decreased with the thermal neutron dose. This study can be useful in determining the thermal neutron dose equivalent in a simple and effective manner using a CR-39 track detector combined with boron converters, facilitating its potential application in neutron dosimetry extended up to 4.761 mSv.

Assessment of radon exhalation rates, effective radium content and radiological exposure dose, of coal and rocks in Tiru Valley Coal Field, India using track etched technique

In this study, the outcomes of assessments of radon exhalation rates for both mass and surface, radium content and annual effective dose from 45 numbers of geological samples in Tiru Valley Coal Field area are presented. The nuclear track detector LR-115 (II) of bulk etch rate, VB = 4 μm h−1 with a spark counter to archive alpha track density of radon was used to measure radon exhalation rate from the samples and to assess radiological exposure in the coalfield area, which has significant geological characteristics. In this work, the surface exhalation rates for coal, carbonaceous shale and sandstone samples have been estimated to be in the range of 217.4–659.9 mBq m−2 h−1, 234.0–381.1 mBq m−2 h−1 and 337.1–741.4 mBq m−2 h−1, respectively. The mass exhalation rates for coal, carbonaceous shale and sandstone samples varied in the range of 6.5–19.8 mBq kg–1 h−1, 7.0–11.4 mBq kg–1 h−1, and 10.1–22.2 mBq kg–1 h−1, respectively. The radium contents have been found to vary in the range of 6.7–20.3 Bq kg−1, 7.2–11.8 Bq kg−1 and 10.4–22.9 Bq kg−1 for coal, carbonaceous shale and sandstone respectively. The annual effective doses related to the inhalation of radon from the exposure to the samples have been estimated to be in the range of 15.8–47.9 μSv y−1, 17.0–27.7 μSv y−1 and 24.5–53.8 μSv y−1 for coal, carbonaceous shale and sandstone respectively. In this investigation, the lifetime fatality-risks have also been assessed. The values were generally higher in rock samples than in coal. However, the findings have shown that the obtained values are within the internationally accepted recommended values.

Radiation Damage in the Structure of the CR-39 Nuclear Detector Material as A Result of the Alpha's Energy Loss

In this work, the damage caused by the passage of alpha particles inside the CR-39 nuclear detector material on its chemical structure was studied. All samples at room temperature using a 241Am-Be neutron source with a flux of 5^10 neutrons.cm-2.s-1 were neutron-irradiated. In the CR-39 nuclear track detectors, chemical etching is a critical step in expanding latent tracks. At 70 °C, a NaOH in 6.25N etchant was found to be useful in expanding alpha traces in the CR-39 detector. The track depths of the Alpha particle as a function of etching time for the various energies were increased as etching time increases. The current study uses the nuclear track detector technique to estimate the range of alpha particles. Track etch rates are frequently determined using 2-dimensional photographs of track openings (diameter) or etching time data. The chemical structure along latent tracks and the track formation process were investigated in PADC(poly allyl diglycol carbonate). The findings showed that the measurement of bulk etch rate values by the weight method was 1.42 ± 0.02 μm/h. In addition, the results for the alpha particle range from 4.47 ± 0.05 and 5.8 ± 0.19 μm for alpha energy1.2 MeV and1.47MeV,respectively

Impact of X-rays on fission fragments track etch parameters in Lexan detector as analyzed by FTIR spectroscopy

Irradiation effects of X-rays (45 min and 90 min) on track etch parameters of Lexan polycarbonate detectors have been studied with respect to structural behavior using Fourier transform infrared spectroscopy (FTIR) spectroscopy. Pre-exposure and post-exposure of X-rays bring significant changes in track etch parameters (bulk etch rate (BER) and track etch rate (TER)) of Lexan polycarbonate detectors at 55[Formula: see text]C to 75[Formula: see text]C. The energy carried by X-rays results in hardening due to cross-linkage and softening due to chain scission of Lexan polycarbonate detectors. BERs and TERs follow Arrhenius equations, and slopes of graph reveal information about activation energy of BERs and TERs. Bulk activation energies calculated are found to be 0.91 eV (unexposed), 0.94 eV (pre-exposed 45 min), 0.96 eV (pre-exposed 90 min), 0.88 eV (post-exposed 45 min) and 0.86 eV (post-exposed 90 min) and are also found to be in agreement with available literature. Track activation energies (TAEs) calculated are found to be 0.74 eV (unexposed), 0.75 eV (pre-exposed 45 min), 0.77 eV (pre-exposed 90 min), 0.74 eV (post-exposed 45 min) and 0.73 eV (post-exposed 90 min). Post-exposure of X-rays for 90 min on Lexan polycarbonate detectors results in enhancement of sensitivity and recorded highest (12.72) at 65[Formula: see text]C. The critical angle of Lexan polycarbonate detectors is also affected by post-exposure of X-rays for 90 min and found maximum (38.59[Formula: see text] at 75[Formula: see text]C. FTIR spectra confirm cross-linkage in Lexan polycarbonate detector during 3 h exposure of fission fragments (FFs) of [Formula: see text]Cf as compared to 2 h exposure.

The Impact of Laser on the Activation Energy and Sensitivity of CR-39 Detector

The influence of laser radiation on bulk and etch rates, and as well detector sensitivity, before and after being irradiated with alpha particles at 5 MeV emitted from a 241Am source, are examined at different etching temperatures (65, 67, 69, 71, 73, 75, 77, 79 ,81, 83, and 85)C in this paper. A laser source with a wavelength of 480 nm and a pulse energy of 50 mJ/pulse at a repetition rate of 9 Hz was used to investigate the activation energy of a CR-39 polymer. The rates of bulk etch, Vb, and track etch, Vt, slightly increase with laser radiation. Whereas sensitivity decreases as temperature increases, besides, alpha-laser samples have quite better sensitivity than other samples. The activation energies of the bulk etch rates, Eb, are equivalent to 0.94 ± 0.07, 0.88 ± 0.05, and 0.95 ± 0.06 eV for laser-alpha, alpha-laser, and no laser samples, respectively. While, the activation energies associated with track etch rate, Et, for the CR-39 samples under study are 0.86 ± 0.04, 0.77 ± 0.03, and 0.76 ± 0.03 eV. The results manifest that laser exposure has a slight influence on activation energies of bulk etch rate within experimental uncertainties of the CR-39 samples. Additionally, the CR-39 set of laser-alpha samples reveals that Et is increased based on the cross-linking process. The increase in Et relates to hardening of the detector material, which has several uses, specifically in radiation detection.