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Mehta V, Kapil C, Shikha D, Kanse S. Time-efficient etching of LR-115 SSNTD film for indoor radon, thoron quantification. Environ Monit Assess 2024; 196:128. [PMID: 38195830 DOI: 10.1007/s10661-024-12296-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 01/01/2024] [Indexed: 01/11/2024]
Abstract
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.
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Affiliation(s)
- Vimal Mehta
- Dept. of Physics, Sri Guru Teg Bahadur Khalsa College, Sri Anandpur Sahib, 140118, India
| | - Chandan Kapil
- Dept. of Physics, Sri Guru Teg Bahadur Khalsa College, Sri Anandpur Sahib, 140118, India
- Dept. of Physics, Punjabi University, Patiala, 147002, India
| | - Deep Shikha
- Dept. of Physics, Sri Guru Teg Bahadur Khalsa College, Sri Anandpur Sahib, 140118, India.
| | - Sandeep Kanse
- Radiological Physics & Advisory Division, Bhabha Atomic Research Centre, Mumbai, 400085, India
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Arun PV, Midhun CV, Musthafa MM, Silpa A, Naiby J, Sreena M, Farhana MPT, Keerthi ES, Deepthi MV, Antony J. Spectroscopic analysis of photoneutrons in intense γ-ray background. Appl Radiat Isot 2023; 200:110944. [PMID: 37499461 DOI: 10.1016/j.apradiso.2023.110944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2023] [Revised: 06/27/2023] [Accepted: 07/13/2023] [Indexed: 07/29/2023]
Abstract
CR-39 SSNTD is used to measure the photoneutron spectrum produced by a medical linear accelerator in an intense γ-ray background. The spectroscopic resolution and the neutron detection threshold have been improved by introducing the event selection criteria, based on the track diameter-brightness correlation. The CR-39 detector's efficiency is determined by adapting the 1H(n,el) cross section from the ENDF/B-VIII.0 evaluations. The measured spectrum was reproduced through Talys-1.96 calculations by implementing the Gogny-HFB microscopic level density model.
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Affiliation(s)
- P V Arun
- Nuclear and Radiation Physics Group, Department of Physics, University of Calicut, Kerala 673635, India.
| | - C V Midhun
- Nuclear and Radiation Physics Group, Department of Physics, University of Calicut, Kerala 673635, India
| | - M M Musthafa
- Nuclear and Radiation Physics Group, Department of Physics, University of Calicut, Kerala 673635, India.
| | - A Silpa
- Department of Radiation Oncology, Malabar Cancer Center, Thalassery, 670103, India
| | - Joseph Naiby
- Caritas Hospital, Thellakom, Kottayam, Kerala 686630, India
| | - M Sreena
- Nuclear and Radiation Physics Group, Department of Physics, University of Calicut, Kerala 673635, India
| | - M P Thesni Farhana
- Nuclear and Radiation Physics Group, Department of Physics, University of Calicut, Kerala 673635, India
| | - E S Keerthi
- Nuclear and Radiation Physics Group, Department of Physics, University of Calicut, Kerala 673635, India
| | - M V Deepthi
- Nuclear and Radiation Physics Group, Department of Physics, University of Calicut, Kerala 673635, India
| | - Joseph Antony
- Nuclear and Radiation Physics Group, Department of Physics, University of Calicut, Kerala 673635, India
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do Nascimento Santos JM, Dos Santos Júnior JA, Dos Santos Amaral R, Cavalcanti Freire Bezerra MB, de Salazar E Fernandes T, Valcárcel Rojas LA, Fernández ZH, Nóbrega de Araújo EE, Isidoro de Araújo Rodrigues Azevedo AJ, Lopes de Barros Correia F, Milán MO. α Espec-222 as a variant to the radon monitoring method using a solid state nuclear track. Appl Radiat Isot 2021; 178:109948. [PMID: 34536831 DOI: 10.1016/j.apradiso.2021.109948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 07/25/2021] [Accepted: 09/10/2021] [Indexed: 11/22/2022]
Abstract
Radon is important in indoor radiometry, where radiological impact is relevant. The improvement of low-cost methods makes it possible to maximize the monitored areas. Thus, a simple and robust monitoring device based on SSNTD CR-39 was designed. Detector conditions were standardized to reduce operational errors and increase productivity. The calibration factor by the slope method allowed efficiency greater than 93%. The monitoring system is satisfactory in terms of operation and performance, suitable for a wide range of radon monitoring situations.
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Rout RP, Mishra R, Prajith R, Jalaluddin S, Sapra BK. Wire mesh capped DRPS based bronchial dosimeter for personal inhalation dosimetry due to radon progeny. J Radiol Prot 2021; 41:398-409. [PMID: 33571976 DOI: 10.1088/1361-6498/abe549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 02/11/2021] [Indexed: 06/12/2023]
Abstract
A study has been carried out to experimentally determine the calibration factor (CF) of the passive bronchial dosimeter, which consists of a direct radon progeny sensor capped with a 100-wire mesh. First, the CF was determined in controlled environmental conditions simulated in a calibration chamber. With aerosol concentrations varying from 104p cm-3to 105p cm-3and relative humidity varying from 60% to 80% in the chamber, CF was observed to be nearly constant with an average value of (3.8 ± 0.5) × 10-3mSv tracks-1cm2. Then, the CF was determined in real indoor environments in which it was again observed to be almost constant and the mean value was found to be (5.6 ± 0.1) × 10-3mSv tracks-1cm2. Pooling all the data on CFs obtained under controlled conditions and in real indoor environments, a lognormal distribution of the CF was observed with a geometric mean and geometric standard deviation of 0.0052 mSv tracks-1cm2and 1.28 respectively. The experimentally determined value of CF was found to be in close agreement with the theoretically estimated value, taking into consideration the unattached fraction of radon progeny. This dosimeter is passive, cheap, lightweight and, moreover, the CF being stable against environmental variations, will be useful in monitoring inhalation doses due to radon progeny for occupational workers.
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Affiliation(s)
- R P Rout
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai 400085, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
| | - R Mishra
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai 400085, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
| | - R Prajith
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai 400085, India
| | - S Jalaluddin
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai 400085, India
| | - B K Sapra
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai 400085, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
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Sanada T. Measurement of Indoor Thoron Gas Concentrations Using a Radon-Thoron Discriminative Passive Type Monitor: Nationwide Survey in Japan. Int J Environ Res Public Health 2021; 18:1299. [PMID: 33535545 PMCID: PMC7908141 DOI: 10.3390/ijerph18031299] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 01/25/2021] [Accepted: 01/29/2021] [Indexed: 11/16/2022]
Abstract
As part of a nationwide survey of thoron (220Rn) in Japan, the indoor 220Rn gas concentrations in 940 dwellings were measured throughout one year, from 1993 to 1996, using a passive type 222Rn-220Rn discriminative monitor. The monitor was placed in a bedroom or a living room in each house for four successive three-month periods. The mean annual indoor 220Rn concentration was estimated from the four measurements in each house. The arithmetic mean, the median and the geometric mean for indoor 220Rn concentrations in 899 dwellings were 20.1, 9.6 and 10.0 Bq m-3, respectively. The 220Rn concentrations exhibited a log-normal distribution. It was found that the 220Rn concentrations were dependent on the nature of the materials used for wall construction and also on the distance of measurement from the wall. Significant seasonal variations in the 220Rn concentration were not observed. It would seem that the nature of the wall material contributed to the increased indoor 220Rn concentrations.
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Affiliation(s)
- Tetsuya Sanada
- Department of Radiological Technology, Faculty of Health Sciences, Hokkaido University of Science, Sapporo, Hokkaido 006-8585, Japan
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Deb A, Gazi M, Ghosh J, Chowdhury S, Barman C. Monitoring of soil radon by SSNTD in Eastern India in search of possible earthquake precursor. J Environ Radioact 2018; 184-185:63-70. [PMID: 29353200 DOI: 10.1016/j.jenvrad.2018.01.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2015] [Revised: 01/09/2018] [Accepted: 01/10/2018] [Indexed: 06/07/2023]
Abstract
The present paper deals with monitoring soil radon-222 concentration at two different locations, designated Site A and Site B, 200 m apart at Jadavpur University campus, Kolkata, India, with a view to find possible precursors for the earthquakes that occurred within a few hundred kilometers from the monitoring site. The solid state nuclear track detector CR-39 has been used for detection of radon gas coming out from soil. Radon-222 time series at both locations during the period August 2012-December 2013 have been analysed. Distinct anomalies in the soil radon time series have been observed for seven earthquakes of magnitude greater than 4.0 M that occurred during this time. Of these, radon anomalies for two earthquakes have been observed at both locations A and B. Absence of anomalies for some other earthquakes has been discussed, and the observations have been compared with some earthquake precursor models.
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Affiliation(s)
- Argha Deb
- School of Studies on Environmental Radioactivity and Archaeological Sciences, Jadavpur University, Kolkata 700032, India
| | - Mahasin Gazi
- School of Studies on Environmental Radioactivity and Archaeological Sciences, Jadavpur University, Kolkata 700032, India
| | - Jayita Ghosh
- School of Studies on Environmental Radioactivity and Archaeological Sciences, Jadavpur University, Kolkata 700032, India
| | - Saheli Chowdhury
- School of Studies on Environmental Radioactivity and Archaeological Sciences, Jadavpur University, Kolkata 700032, India
| | - Chiranjib Barman
- Centre for Astroparticle Physics and Space Science, Bose Institute, Block-EN, Sector-V, Bidhannagar, Kolkata 700091, India.
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Abstract
Two methods were proposed for determining alpha-particle fluence for radiobiological experiments. The first involved calculating the probabilities of hitting the target for alpha particles emitted from a source through Monte Carlo simulations, which when multiplied by the activity of the source gave the fluence at the target. The second relied on the number of chemically etched alpha-particle tracks developed on a solid-state nuclear track detector (SSNTD) that was irradiated by an alpha-particle source. The etching efficiencies (defined as percentages of latent tracks created by alpha particles from the source that could develop to become visible tracks upon chemical etching) were computed through Monte Carlo simulations, which when multiplied by the experimentally counted number of visible tracks would also give the fluence at the target. We studied alpha particles with an energy of 5.486 MeV emitted from an 241Am source, and considered the alpha-particle tracks developed on polyallyldiglycol carbonate film, which is a common SSNTD. Our results showed that the etching efficiencies were equal to one for source-film distances of from 0.6 to 3.5 cm for a circular film of radius of 1 cm, and for source-film distances of from 1 to 3 cm for circular film of radius of 2 cm. For circular film with a radius of 3 cm, the etching efficiencies never reached 1. On the other hand, the hit probability decreased monotonically with increase in the source-target distance, and fell to zero when the source-target distance was larger than the particle range in air.
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Affiliation(s)
- Dragoslav Nikezic
- Department of Physics and Materials Science, City University of Hong Kong, Kowloon Tong, Hong Kong
- Faculty of Science, University of Kragujevac, Kragujevac, Serbia
| | - Kwan Ngok Yu
- Department of Physics and Materials Science, City University of Hong Kong, Kowloon Tong, Hong Kong
- State Key Laboratory in Marine Pollution, City University of Hong Kong, Kowloon Tong, Hong Kong
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Azooz AA, Al-Jubbori MA. Alpha particles energy estimation from track diameter development in a CR-39 detector. Appl Radiat Isot 2016; 115:74-80. [PMID: 27341133 DOI: 10.1016/j.apradiso.2016.06.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 06/07/2016] [Accepted: 06/07/2016] [Indexed: 01/09/2023]
Abstract
The slight nonlinearity in temporal development of tracks diameter in CR-39 nuclear track detectors is examined with the aim of attempting to find if such nonlinearity can be directly related to the charged particle energy. Narrowly spaced etching time-diameter experimental data for alpha particles at five energy values and for one additional energy value etched at five different temperatures are obtained. Initial results show good indication that measuring such time-diameter relationship can form a useful energy estimation tool. Good consistency with other independent published results is obtained.
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Affiliation(s)
- Aassim A Azooz
- Department of Physics, College of Science, Mosul University, Mosul, Iraq.
| | - Mushtaq A Al-Jubbori
- Department of Physics, College of Education for Pure Science, Mosul University, Mosul, Iraq.
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Mayya YS, Sahoo BK. A note on "an erroneous formula in use for estimating radon exhalation rates from samples using sealed can technique". Appl Radiat Isot 2016; 111:8-9. [PMID: 26896680 DOI: 10.1016/j.apradiso.2016.01.032] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Revised: 01/14/2016] [Accepted: 01/29/2016] [Indexed: 12/01/2022]
Abstract
In this note, we point out a serious fallacy in a formula that has appeared in literature for calculating the (222)Rn exhalation rates using the Solid-State Nuclear Track Detector (SSNTD) based sealed can technique. It is shown that this formula underestimates true exhalation rates by a factor of more than 10(6). Several publications have used this formula instead of the well-known Abu-Jarad formula and have reported unrealistically low (µBq/m(2)/d) surface exhalation rates for normal materials.
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Affiliation(s)
- Y S Mayya
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai 400076, India
| | - B K Sahoo
- Radiological Physics & Advisory Division, Bhabha Atomic Research Centre, Mumbai 400085, India.
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Shweikani R, Anjak O. Estimation of photoneutron intensities around radiotherapy linear accelerator 23-MV photon beam. Appl Radiat Isot 2015; 99:168-71. [PMID: 25770858 DOI: 10.1016/j.apradiso.2015.03.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2014] [Revised: 02/16/2015] [Accepted: 03/03/2015] [Indexed: 11/24/2022]
Abstract
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 40×40cm(2) 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.
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Affiliation(s)
- R Shweikani
- Atomic Energy Commission of Syria, P.O. Box 6091, Damascus, Syria.
| | - O Anjak
- Atomic Energy Commission of Syria, P.O. Box 6091, Damascus, Syria
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Amanat B, Kardan MR, Faghihi R, Hosseini Pooya SM. Comparative Measurements of Radon Concentration in Soil Using Passive and Active Methods in High Level Natural Radiation Area (HLNRA) of Ramsar. J Biomed Phys Eng 2013; 3:139-144. [PMID: 25505760 PMCID: PMC4204504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2013] [Accepted: 09/26/2013] [Indexed: 06/04/2023]
Abstract
BACKGROUND Radon and its daughters are amongst the most important sources of natural exposure in the world. Soil is one of the significant sources of radon/thoron due to both radium and thorium so that the emanated thoron from it may cause increased uncertainties in radon measurements. Recently, a diffusion chamber has been designed and optimized for passive discriminative measurements of radon/thoron concentrations in soil. OBJECTIVE In order to evaluate the capability of the passive method, some comparative measurements (with active methods) have been performed. METHOD The method is based upon measurements by a diffusion chamber, including two Lexan polycarbonate SSNTDs, which can discriminate the emanated radon/thorn from the soil by delay method. The comparative measurements have been done in ten selected points of HLNRA of Ramsar in Iran. The linear regression and correlation between the results of two methods have been studied. RESULTS The results show that the radon concentrations are within the range of 12.1 to 165 kBq/m(3) values. The correlation between the results of active and passive methods was measured by 0.99 value. As well, the thoron concentrations have been measured between 1.9 to 29.5 kBq/m(3) values at the points. CONCLUSION The sensitivity as well as the strong correlation with active measurements shows that the new low-cost passive method is appropriate for accurate seasonal measurements of radon and thoron concentration in soil.
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Affiliation(s)
- B Amanat
- Department of physics, Payame Noor University, Po Box 19395-3697, Tehran, Iran
| | - M R Kardan
- Radiation Application School, Nuclear Sciences and Technology Institute, Tehran, Iran
- Iran Nuclear Regulatory Authority, Tehran, Iran
| | - R Faghihi
- Radiation Research Center, Shiraz University, Shiraz, Iran
- Nuclear Engineering Departments, Shiraz University, Shiraz, Iran
| | - S M Hosseini Pooya
- Radiation Application School, Nuclear Sciences and Technology Institute, Tehran, Iran
- Iran Nuclear Regulatory Authority, Tehran, Iran
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