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Golovko VV, Kamaev O, Sun J, Jillings CJ, Gorel P, Vázquez-Jáuregui E. Ambient Dose and Dose Rate Measurement in SNOLAB Underground Laboratory at Sudbury, Ontario, Canada. SENSORS (BASEL, SWITZERLAND) 2023; 23:1945. [PMID: 36850546 PMCID: PMC9962506 DOI: 10.3390/s23041945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 01/19/2023] [Accepted: 01/31/2023] [Indexed: 06/18/2023]
Abstract
The paper describes a system and experimental procedure that use integrating passive detectors, such as thermoluminescent dosimeters (TLDs), for the measurement of ultra-low-level ambient dose equivalent rate values at the underground SNOLAB facility located in Sudbury, Ontario, Canada. Because these detectors are passive and can be exposed for relatively long periods of time, they can provide better sensitivity for measuring ultra-low activity levels. The final characterization of ultra-low-level ambient dose around water shielding for ongoing direct dark matter search experiments in Cube Hall at SNOLAB underground laboratory is given. The conclusion is that TLDs provide reliable results in the measurement of the ultra-low-level environmental radiation background.
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Affiliation(s)
- Victor V. Golovko
- Canadian Nuclear Laboratories, 286 Plant Road, Chalk River, ON K0J 1J0, Canada
| | - Oleg Kamaev
- Canadian Nuclear Laboratories, 286 Plant Road, Chalk River, ON K0J 1J0, Canada
| | - Jiansheng Sun
- Canadian Nuclear Laboratories, 286 Plant Road, Chalk River, ON K0J 1J0, Canada
| | | | | | - Eric Vázquez-Jáuregui
- Instituto de Física, Universidad Nacional Autónoma de México, A. P. 20-364, Mexico City 01000, Mexico
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2
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Tiwari B, Chaudhary RK, Srivastava A, Kumar R, Sonawane M. Tissue-equivalent dosimeters based on copper doped lithium tetraborate single crystals for radiotherapy. RADIAT MEAS 2022. [DOI: 10.1016/j.radmeas.2022.106704] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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3
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Jung A, Matusiak K. The impact of accidental immersion in selected liquids on the sensitivity and repeatability of MCP-N thermoluminescent detectors. RADIAT MEAS 2021. [DOI: 10.1016/j.radmeas.2021.106525] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Chand S, Mehra R, Chopra V. Recent developments in phosphate materials for their thermoluminescence dosimeter (TLD) applications. LUMINESCENCE 2020; 36:1808-1817. [PMID: 33047494 DOI: 10.1002/bio.3960] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 08/26/2020] [Accepted: 10/01/2020] [Indexed: 11/06/2022]
Abstract
The use of phosphate-based thermoluminescence dosimeter (TLD) materials in current scenarios is presented here, particularly for the field of low dosimetry. TLD materials are currently researched for their use in for example environmental dosimetry, personal dosimetry, and medical dosimetry. There are several TLD materials available such as: sulphates, borates, fluorides, and sulphides, including some metal oxides and perovskites, which are the most used and have been widely explored. In the present scenario, new interest is being focused on the need for thermoluminescent materials for application in material science and radiation dosimetry for low-dose dosimetry. These doped TLDs are prepared using different techniques including solid-state reaction methods, combustion methods, wet chemical methods, and sol gel methods. Therefore, among the above stated TLDs, phosphates have opened a new door in radiation dosimetry, particularly in low-dose dosimetry over the last few years. This paper mainly deals with a review of various phosphate-based TLD materials and recent advancements in phosphates for TL dosimetry.
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Affiliation(s)
- Sansar Chand
- Department of Physics, Dr. BR. Ambedkar National Institute of Technology, Jalandhar, Punjab, India
| | - Rohit Mehra
- Department of Physics, Dr. BR. Ambedkar National Institute of Technology, Jalandhar, Punjab, India
| | - Vibha Chopra
- P.G. Department of Physics and Electronics, DAV College Amritsar, Punjab, India
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Charubala CS, Annalakshmi O, Jakathamani S, Sankaran MR, Venkatraman B, Jose MT. Studies on pelletised lithium magnesium borate TL material for eye lens dosimetry. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2019; 39:178-192. [PMID: 30602145 DOI: 10.1088/1361-6498/aafb7c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Recent epidemiological studies in various cohorts confirm that radiation induced cataract may occur at a threshold dose as low as 0.5 Gy. ICRP has recognised the higher radiosensitivity of eye lens and recommended to reduce annual eye lens dose limit from 150 to 20 mSv. Present dosimetry for eye lens is largely based on LiF based dosimeters. The present work is an attempt towards using near tissue equivalent lithium borate material namely lithium magnesium borate doped with terbium (LMB:Tb) in eye lens dosimetry. The material in powder form was synthesised using solid state sintering method and pelletised using poly tetra fluoro ethylene (PTFE) as binding agent. It was observed that 130 mg of 1 mm thick LMB:Tb pellet bound with PTFE showed stable glow curve structure and attractive dosimetric features in terms of sensitivity, fading, linearity, reusability etc. A proposal of 1.5 mm Teflon encapsulation corresponding to tissue equivalent thickness of 3 mm was put forward for an ideal dosimeter for the measurement in terms of Hp(3). Energy and angular dependence studies based on FLUKA simulations suggest a flat response for the prototype design. In addition to PTFE, various tissue equivalent encapsulations such as polyimide, polyamide 6 and PMMA were also evaluated using FLUKA code.
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Affiliation(s)
- C S Charubala
- Health Physics Division, Bhabha Atomic Research Centre, Kalpakkam-603102, Tamilnadu, India. Homi Bhabha National Institute, Indira Gandhi Center for Atomic Research, Kalpakkam-603102, Tamilnadu, India
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6
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Comparison of thermoluminescent readers exploring different reading protocols for LiF:Mg,Cu,P (MCP-N) detectors. RADIAT MEAS 2019. [DOI: 10.1016/j.radmeas.2018.11.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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7
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Zorko B, Kneževic Ž, Crnic B, Majer M, Ranogajec-Komor M. A Transnational Intercomparison of Environmental Dosemeters in Realistic Environmental Conditions. RADIATION PROTECTION DOSIMETRY 2017; 174:287-290. [PMID: 27150518 DOI: 10.1093/rpd/ncw109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 04/05/2016] [Indexed: 06/05/2023]
Abstract
Environmental dosemeters were benchmarked against various dosimetry systems in realistic environmental conditions. For the first time, the dosemeters, provided by two institutions from two different countries, were deployed at 20 sites in Slovenia and Croatia (near the Nuclear Power Plant, NPP Krško, Slovenia) during two semi-annual periods: summer-autumn and winter-spring. The results obtained using the different dosimetry systems show interesting features concerning local environmental peculiarities. The results of the intercomparison demonstrate an excellent agreement of the ambient doses measured independently by two different institutions and three passive dosimetry systems. Such consistency is crucial for the environmental dosimetry.
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Affiliation(s)
- Benjamin Zorko
- Jožef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
| | - Željka Kneževic
- Ruder Boškovic Institute, Bijenicka cesta 54, 10000 Zagreb, Croatia
| | - Boštjan Crnic
- Jožef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
| | - Marija Majer
- Ruder Boškovic Institute, Bijenicka cesta 54, 10000 Zagreb, Croatia
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Entezam A, Khandaker MU, Amin YM, Ung NM, Bradley DA, Maah J, Safari MJ, Moradi F. Thermoluminescence Response of Ge-Doped Cylindrical-, Flat- and Photonic Crystal Silica-Fibres to Electron and Photon Radiation. PLoS One 2016; 11:e0153913. [PMID: 27149115 PMCID: PMC4857927 DOI: 10.1371/journal.pone.0153913] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 04/06/2016] [Indexed: 11/20/2022] Open
Abstract
Study has been made of the thermoluminescence (TL) response of silica-based Ge-doped cylindrical, flat and photonic crystal fibres (referred to herein as PCF-collapsed) to electron (6, 12 and 20 MeV) and photon (6, 10 MV) irradiation and 1.25 MeV γ-rays, for doses from 0.1 Gy to 100 Gy. The electron and photon irradiations were delivered through use of a Varian Model 2100C linear accelerator located at the University of Malaya Medical Centre and γ-rays delivered from a 60Co irradiator located at the Secondary Standard Dosimetry Laboratory (SSDL), Malaysian Nuclear Agency. Tailor-made to be of various dimensions and dopant concentrations (6-10% Ge), the fibres were observed to provide TL yield linear with radiation dose, reproducibility being within 1-5%, with insensitivity to energy and angular variation. The sensitivity dependency of both detectors with respect to field size follows the dependency of the output factors. For flat fibres exposed to 6 MV X-rays, the 6% Ge-doped fibre provided the greatest TL yield while PCF-collapsed showed a response 2.4 times greater than that of the 6% Ge-doped flat fibres. The response of cylindrical fibres increased with core size. The fibres offer uniform response, high spatial resolution and sensitivity, providing the basis of promising TL systems for radiotherapy applications.
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Affiliation(s)
- A. Entezam
- Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - M. U. Khandaker
- Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Y. M. Amin
- Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - N. M. Ung
- Clinical Oncology Unit, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - D. A. Bradley
- Department of Physics, University of Surrey, Guildford, GU2 7XH, United Kingdom
| | - J. Maah
- Department of Chemistry, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - M. J. Safari
- Department of Biomedical Imaging, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - F. Moradi
- Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
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Patil RR, Gaikwad SU, More YK, Kulkarni MS, Bhatt BC, Moharil SV. A new highly sensitive low-Z LiF-based OSL phosphor for radiation dosimetry. RADIATION PROTECTION DOSIMETRY 2016; 168:465-470. [PMID: 26347541 DOI: 10.1093/rpd/ncv378] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2015] [Accepted: 07/18/2015] [Indexed: 06/05/2023]
Abstract
A new low-Z lithium fluoride-based optical stimulated luminescent (OSL) phosphor is developed. The phosphor shows good OSL properties, and its sensitivity is comparable with that of the commercial Al2O3:C (Landauer, Inc.) phosphor. For the luminescence averaged over initial 3 s, blue stimulated luminescence (BSL) and green stimulated luminescence (GSL) sensitivities were found to be 0.27 and 4 times, respectively, than that of Al2O3:C (Landauer, Inc.). The BSL decay is fast, and the whole signal decays within 3 s; the GSL decay is relatively slow, and the signal decays in 25 s. The fast decay, good sensitivity, good linearity and its near tissue equivalence (Zeff ∼8.14) will make this phosphor suitable for radiation dosimetry particularly in personnel as well as in medical dosimetry.
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Affiliation(s)
- R R Patil
- Institute of Science, R.T. Road Civil Lines, Nagpur, India
| | - S U Gaikwad
- Institute of Science, R.T. Road Civil Lines, Nagpur, India
| | - Y K More
- Institute of Science, R.T. Road Civil Lines, Nagpur, India
| | - M S Kulkarni
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai, India
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Seth P, Rajput S, Rao S, Aggarwal S. Investigations of thermoluminescence properties of multicrystalline LiF: Mg, Cu, Si phosphor prepared by edge defined film fed growth technique. RADIAT MEAS 2016. [DOI: 10.1016/j.radmeas.2015.09.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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11
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12
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Photon dosimetry methods outside the target volume in radiation therapy: Optically stimulated luminescence (OSL), thermoluminescence (TL) and radiophotoluminescence (RPL) dosimetry. RADIAT MEAS 2013. [DOI: 10.1016/j.radmeas.2013.03.004] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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13
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Miljanić S, Hršak H, Knežević Ž, Majer M, Heinrich Z. Peripheral doses in children undergoing Gamma Knife radiosurgery and second cancer risk. RADIAT MEAS 2013. [DOI: 10.1016/j.radmeas.2012.09.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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14
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15
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Kelemen A, Mesterházy D, Ignatovych M, Holovey V. Thermoluminescence characterization of newly developed Cu-doped lithium tetraborate materials. Radiat Phys Chem Oxf Engl 1993 2012. [DOI: 10.1016/j.radphyschem.2012.01.041] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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16
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Knežević Ž, Beck N, Milković Đ, Miljanić S, Ranogajec-Komor M. Characterisation of RPL and TL dosimetry systems and comparison in medical dosimetry applications. RADIAT MEAS 2011. [DOI: 10.1016/j.radmeas.2011.05.042] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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17
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Gajski G, Milković D, Ranogajec-Komor M, Miljanić S, Garaj-Vrhovac V. Application of dosimetry systems and cytogenetic status of the child population exposed to diagnostic X-rays by use of the cytokinesis-block micronucleus cytome assay. J Appl Toxicol 2010; 31:608-17. [PMID: 21089162 DOI: 10.1002/jat.1603] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2010] [Revised: 09/06/2010] [Accepted: 09/07/2010] [Indexed: 11/10/2022]
Abstract
Low-dose ionizing radiation used for medical purposes is one of the definite risk factors for cancer development, and children exposed to ionizing radiation are at a relatively greater cancer risk as they have more rapidly dividing cells than adults and have longer life expectancy. Since cytokinesis-block micronucleus cytome (CBMN Cyt) assay has become one of the standard endpoints for radiation biological dosimetry, we used that assay in the present work for the assessment of different types of chromosomal damage in children exposed to diagnostic X-ray procedures. Twenty children all with pulmonary diseases between the ages of 4 and 14 years (11.30 ± 2.74) were evaluated. Absorbed dose measurements were conducted for posterior-anterior projection on the forehead, thyroid gland, gonads, chest and back. Doses were measured using thermoluminescence and radiophotoluminescent dosimetry systems. It was shown that, after diagnostic X-rays, the mean total number of CBMN Cyt assay parameters (micronucleus, nucleoplasmic bridges and nuclear buds) was significantly higher than prior to diagnostic procedure and that interindividual differences existed for each monitored child. For the nuclear division index counted prior and after examination, no significant differences were noted among mean group values. These data suggest that even low-dose diagnostic X-ray exposure may induce damaging effect in the somatic DNA of exposed children, indicating that immense care should be given in both minimizing and optimizing radiation exposure to diminish the radiation burden, especially in the youngest population.
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Affiliation(s)
- Goran Gajski
- Institute for Medical Research and Occupational Health, Mutagenesis Unit, 10000 Zagreb, Croatia
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18
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Milkovic D, Garaj-Vrhovac V, Ranogajec-Komor M, Miljanic S, Gajski G, Knezevic Z, Beck N. Primary DNA damage assessed with the comet assay and comparison to the absorbed dose of diagnostic X-rays in children. Int J Toxicol 2010; 28:405-16. [PMID: 19815846 DOI: 10.1177/1091581809344775] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The aim of this work is to assess DNA damage in peripheral blood lymphocytes of children prior to and following airway X-ray examinations of the chest using the alkaline comet assay and to compare data with the measured absorbed dose. Twenty children with pulmonary diseases, between the ages of 5 and 14 years, are assessed. Absorbed dose measurements are conducted for posterior-anterior projection on the forehead, thyroid gland, gonads, chest, and back. Doses are measured using thermoluminescent and radiophotoluminescent dosimetry systems. Differences between tail lengths, tail intensity, and tail moments as well as for the long-tailed nuclei before and after exposures are statistically significant and are dependent on the individual. The results demonstrate the usefulness of the comet assay as a measure of X-ray damage to lymphocytes in a clinical setting. Doses measured with both dosimeters show satisfactory agreement (0.01 mSv) and are suitable for dosimetric measurements in X-ray diagnostics.
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Knežević Ž, Ranogajec-Komor M, Miljanić S. Effect of dopants on TL characteristics of LiF:Mg,Cu,P detectors. RADIAT MEAS 2010. [DOI: 10.1016/j.radmeas.2009.12.033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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20
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Jeng SC, Tsai CL, Chan WT, Tung CJ, Wu JK, Cheng JCH. Mathematical estimation and in vivo dose measurement for cone-beam computed tomography on prostate cancer patients. Radiother Oncol 2009; 92:57-61. [DOI: 10.1016/j.radonc.2009.03.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2008] [Revised: 03/08/2009] [Accepted: 03/08/2009] [Indexed: 10/20/2022]
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21
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Järvinen H, Buls N, Clerinx P, Miljanic S, Nikodemová D, Ranogajec-Komor M, Struelens L, d'Errico F. Comparison of double dosimetry algorithms for estimating the effective dose in occupational dosimetry of interventional radiology staff. RADIATION PROTECTION DOSIMETRY 2008; 131:80-86. [PMID: 18757899 DOI: 10.1093/rpd/ncn239] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
'Double dosimetry' i.e. measurement with two dosemeters, one located above the protective apron and one under has been recommended in interventional radiology (IR) to determine the effective dose to staff. Several algorithms have been developed to calculate the effective dose from the readings of the two dosemeters, but there is no international consensus on what is the best algorithm. In this work, a few of the most recently developed algorithms have been tested in typical IR conditions. The effective dose and personnel dosemeter readings were obtained experimentally by using thermoluminescent dosemeters in and on a Rando-Alderson phantom provided with a lead apron. In addition, the effective dose and personnel dosemeter readings were calculated by the Monte Carlo method for the same irradiation geometry. The results suggest that most of the algorithms overestimate effective dose in the selected IR conditions, but there is also a risk of underestimation by using the least conservative algorithms. Two of the algorithms seem to comply best with the chosen criteria of performance, i.e. no underestimation, minimum overestimation and close estimation of effective dose in typical IR conditions. However, it might not be justified to generalise the results. It is recommended that whenever personnel doses approach or exceed the dose limit, IR conditions should be further investigated and the possibility of over- or under-estimation of effective dose by the algorithm used should be considered.
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Affiliation(s)
- H Järvinen
- Radiation and Nuclear Safety Authority (STUK), Helsinki, Finland.
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Kim J, Lee J, Pradhan A, Kim B, Kim J. Further studies on the dosimetric characteristics of LiF:Mg,Cu,Si—A high sensitivity thermoluminescence dosimeter (TLD). RADIAT MEAS 2008. [DOI: 10.1016/j.radmeas.2007.10.045] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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24
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Kelemen A, Holovey V, Ignatovych M. Relative yields of radioluminescence and thermoluminescence in manganese- and silver-doped lithium tetraborate phosphors. RADIAT MEAS 2008. [DOI: 10.1016/j.radmeas.2007.11.083] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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25
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Vuković B, Radolić V, Lisjak I, Vekić B, Poje M, Planinić J. Some cosmic radiation dose measurements aboard flights connecting Zagreb Airport. Appl Radiat Isot 2007; 66:247-51. [PMID: 17935999 DOI: 10.1016/j.apradiso.2007.09.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2006] [Revised: 08/07/2007] [Accepted: 09/03/2007] [Indexed: 10/22/2022]
Abstract
When primary particles from space, mainly protons, enter the atmosphere, they produce interactions with air nuclei, and cosmic-ray showers are induced. The radiation field at aircraft altitude is complex, with different types of particles, mainly photons, electrons, positrons and neutrons, with a large energy range. The non-neutron component of cosmic radiation dose aboard A320 and ATR40 aircraft was measured with TLD-100 (LiF:Mg,Ti) detectors and the Mini 6100 semiconductor dosimeter; the neutron dose was measured with the neutron dosimeter consisted of LR-115 track detector and boron foil BN-1 or 10B converter. The estimated occupational effective dose for the aircraft crew (A320) working 500 h per year was 1.64 mSv. Another experiment was performed at the flights Zagreb-Paris-Buenos Aires and reversely, when one measured non-neutron cosmic radiation dose; for 26.7 h of flight, the MINI 6100 dosimeter gave an average dose rate of 2.3 microSv/h and the TLD dosimeter registered the dose equivalent of 75 microSv or the average dose rate of 2.7 microSv/h; the neutron dosimeter gave the dose rate of 2.4 microSv/h. In the same month, February 2005, a traveling to Japan (24-h-flight: Zagreb-Frankfurt-Tokyo and reversely) and the TLD-100 measurement showed the average dose rate of 2.4microSv/h; the neutron dosimeter gave the dose rate of 2.5 microSv/h. Comparing dose rates of the non-neutron component (low LET) and the neutron one (high LET) of the radiation field at the aircraft flight level, we could conclude that the neutron component carried about 50% of the total dose, that was near other known data.
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Affiliation(s)
- B Vuković
- Department of Physics, University of Osijek, Osijek, P.O. Box 125, Croatia
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Vuković B, Radolić V, Miklavcić I, Poje M, Varga M, Planinić J. Cosmic radiation dose in aircraft--a neutron track etch detector. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2007; 98:264-73. [PMID: 17600597 DOI: 10.1016/j.jenvrad.2007.05.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2007] [Revised: 04/26/2007] [Accepted: 05/14/2007] [Indexed: 05/16/2023]
Abstract
Cosmic radiation bombards us at high altitude by ionizing particles. The radiation environment is a complex mixture of charged particles of solar and galactic origin, as well as of secondary particles produced in interaction of the galactic cosmic particles with the nuclei of atmosphere of the Earth. The radiation field at aircraft altitude consists of different types of particles, mainly photons, electrons, positrons and neutrons, with a large energy range. The non-neutron component of cosmic radiation dose aboard ATR 42 and A 320 aircrafts (flight level of 8 and 11 km, respectively) was measured with TLD-100 (LiF:Mg,Ti) detectors and the Mini 6100 semiconductor dosimeter. The estimated occupational effective dose for the aircraft crew (A 320) working 500 h per year was 1.64 mSv. Other experiments, or dose rate measurements with the neutron dosimeter, consisting of LR-115 track detector and boron foil BN-1 or 10B converter, were performed on five intercontinental flights. Comparison of the dose rates of the non-neutron component (low LET) and the neutron one (high LET) of the radiation field at the aircraft flight level showed that the neutron component carried about 50% of the total dose. The dose rate measurements on the flights from the Middle Europe to the South and Middle America, then to Korea and Japan, showed that the flights over or near the equator region carried less dose rate; this was in accordance with the known geomagnetic latitude effect.
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Affiliation(s)
- B Vuković
- Department of Physics, University of Osijek, 31000 Osijek, P.O. Box 125, Gajev trg 6, Croatia
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Miljanić S, Ranogajec-Komor M, Knezević Z, Stuhec M, Prokić M. Comparative study of LiF:Mg,Cu,Na,Si and Li2B4O7:Cu,Ag,P TL detectors. RADIATION PROTECTION DOSIMETRY 2006; 119:191-6. [PMID: 16709712 DOI: 10.1093/rpd/nci557] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Recently, two new types of 'tissue equivalent' thermoluminescent detectors (TLDs) have aroused attention: LiF:Mg,Cu,Na,Si and Li2B4O7:Cu,Ag,P. In this work the characteristics of both detectors were compared with the characteristics of the well-known type LiF:Mg,Ti detector, TLD-100. The following properties were investigated: the glow curve structures, relative sensitivity, batch homogeneity and uniformity, detection threshold, reproducibility of the response, linearity in the wide dose range and fading. Also, the energy dependence for medium and low energy X rays was determined in the range of mean energies between 33 and 116 keV. The results confirmed 'tissue equivalency' of both new types in the investigated range of photon energies. LiF:Mg,Cu,Na,Si detector has very high sensitivity (approximately 75 times higher than that of TLD-100) and is convenient for use in a very low range of doses. Li2B4O7:Cu,Ag,P detector shows some improvements in comparison with the previously prepared types of lithium borate. The most important is the five times higher sensitivity than that of TLD-100. This detector is also very promising, especially in medical dosimetry.
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Affiliation(s)
- S Miljanić
- Ruder Bosković Institute, Bijenicka 54, 10000 Zagreb, Croatia.
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Zorko B, Miljanić S, Vekić B, Stuhec M, Gobec S, Ranogajec-Komor M. Intercomparison of dosimetry systems based on CaF2:Mn TL detectors. RADIATION PROTECTION DOSIMETRY 2006; 119:300-5. [PMID: 16735564 DOI: 10.1093/rpd/nci640] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The responses of readings by the TL dosimetry system MR200 TL developed in-house and used at JSI and the TOLEDO TL system used at RBI are compared. Ten measurements at different doses ranging from 0.01 mSv to 5 Sv were carried out. A set of 36 dosemeters with three pellets of CaF2:Mn were irradiated in radiation fields of 137Cs and 60Co. Analysis of the measured results shows that at doses below 0.1 Sv, readers' outputs do not differ >5% from each other. At doses >1 Sv, the results obtained by the MR200 reader must be corrected with a known factor. Finally, the reproducibility of the results from the MR200 was tested.
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Affiliation(s)
- B Zorko
- Jozef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia.
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29
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Kovacević N, Vrtar M, Vekić B. A simple calibration method for 106Ru–106Rh eye applicators. Radiother Oncol 2005; 74:293-9. [PMID: 15763310 DOI: 10.1016/j.radonc.2004.12.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2004] [Revised: 10/25/2004] [Accepted: 12/10/2004] [Indexed: 10/26/2022]
Abstract
Ru-Rh eye applicators are used for the radiotherapy of eye malignancies such as melanomas. We present a method of dosimetry of these beta particle emitting applicators. Method is based on a Plexiglas phantom (constructed for this purpose) containing spherical shells and very small, 1x1x1mm3 thermoluminescent dosimeters (TLD) as dosimeters. We determined 3-D depth doses and interpolated depth dose functions. Surface dose rate inhomogeneities and the consequences were considered and discussed. A possible influence of photon component of the emission on the results was analysed. The method has overall combined uncertainty + or -6% which is comparable, and slightly better, than other recent dosimetric methods.
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Affiliation(s)
- Nenad Kovacević
- Clinic of Oncology, University Hospital Centre Rebro, Kispatićeva 12, 10000 Zagreb, Croatia
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Brnić Z, Vekić B, Hebrang A, Anić P. Efficacy of breast shielding during CT of the head. Eur Radiol 2003; 13:2436-40. [PMID: 12827426 DOI: 10.1007/s00330-003-1945-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2002] [Revised: 12/18/2002] [Accepted: 03/17/2003] [Indexed: 11/26/2022]
Abstract
In light of increasing frequency of CT examinations in the past decades, the aims of this prospective study were to investigate scatter radiation breast exposure in head CT and its dependence upon body constitution, and to assess the efficacy of lead shielding as a means of breast dose reduction. In 49 women referred to head CT for objective medical reasons one breast was covered with lead apron during CT scanning. Radiation doses were measured by use of thermoluminescent dosimeters, at skin of both breasts and over the apron. The doses were then compared as well as correlated to body mass index and meatus acusticus externus-to-dosimeter distance, respectively. Average exposure at the skin of the unshielded breast was 0.28 mGy (range 0.15-0.41 mGy), compared with 0.13 mGy (range 0.05-0.29 mGy) at the shielded breast. The doses showed a mean reduction by 57% due to lead shielding. At least half of breast exposure was imparted to the breast from outside, whereas the remainder results from internal scatter. The higher the body mass index, the higher the percentage of internal scatter in total breast dose. Although the level of scatter radiation to the breast is generally low during head CT examination, the use of lead cover enables recognizable further reduction of the exposure, and is recommended as a feasible and effective procedure of breast protection during CT of the head.
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Affiliation(s)
- Z Brnić
- Department of Diagnostic and Interventional Radiology, University Hospital Merkur, Zajceva 19, 10000, Zagreb, Croatia.
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Ranogajec-Komor M. Thermoluminescence Dosimetry-Application in Environmental Monitoring. ACTA ACUST UNITED AC 2003. [DOI: 10.12950/rsm2002.2.2] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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