Determination of uniformity and field size of reference X-ray beams

Cilj ovog rada je da se ispita uniformnost i veličina referentnog polja generisanog pomoću generatora X-zračenja. U tu svrhu je koriššena jonizaciona komora male zapremine tako što su mapirane jačine doze. Na osnovu merenja, određen je korekcioni faktor za neuniformnost polja zračenja. Rezultati prikazani u ovom radu se odnose na polje kolimisano pomoću aperture prečnika 4,2 cm i generisano pomoću generatora X-zračenja konstantnog napona i struje. Ispitivanje je izvršeno u kvalitetu zračenja koji se koristi u dijagnostičkoj radiologiji, ali je ova procedura takođe primenjiva i na kvalitete koji se koriste za etaloniranje uređaja za zaštitu od zračenja definisane u novoj verziji ISO 4037 iz 2019. godine.The aim of this paper is to study the uniformity and the size of a reference radiation field produced by an x-ray generator. This work uses a technique to map dose distribution and measure dose rates with a small-volume spherical ionization chamber in order to determine the correction factor for non uniformity of the radiation field. Results shown in this paper are profile measurementsperformed in radiation beam collimated by a 4.2 cm diameter aperture, generated by calibration x-ray equipment of constant voltage and current. Thestudy was conducted in a diagnostic radiology radiation quality, but this procedure is also applicable to the new revised version of ISO 4037 standard from 2019 which specifies protection level reference radiation qualities.Proceedings: [http://vinar.vin.bg.ac.rs/handle/123456789/8681]XXX симпозијум ДЗЗСЦГ (Друштва за заштиту од зрачења Србије и Црне Горе), 2- 4. октобар 2019. године, Дивчибаре, Србиј

EURAMET i DOSEtrace project and supplementary comparison

Tačna i sledljiva merenja operativnih veličina su neophodna za adekvatnu zaštitu od zračenja. Nacionalni metrološki instituti i Imenovani instituti su zaduženi za diseminaciju SI jedinice Sivert i za etaloniranje korisničke opreme. Ipak, u velikom broju Evropskih zemalja, mogušnosti etaloniranjaza operativne veličine su nedovoljno razvijene ili nepostoješe. Glavni cilj DOSEtrace projekta je unapređenje ovih mogućnosti, kao i smanjenje proširene merne nesigurnosti učesnika projekta ispod 5 % (k = 2). U okviru projekta še biti sprovedena Dodatna interkomparacija kalibracionih faktora za ambijentalni dozni ekvivalent. Ova interkomparacija še pomoši učesnicima projekta da validiraju merne mogušnosti razvijene pre i tokom projekta, a takođe će pomoći novim institutima da steknu međunarodno priznanje. U okviru intercomparacije, biše pokriveni kvaliteti zračenja radionuklida, kao i x-zračenja.Accurate and traceable measurements of operational quantities are required for adequate radiation protection. National Measurement Institutes (NMI) and Designated Institutes (DI) are responsible for disseminating the SI unit sievert and for calibrating user equipment. However, in many emerging European countries, calibration and measurement capabilities for operational quantities are limited or nonexistent. The main objective of DOSEtrace project is to improve these capabilities and for the participants to achieve the expanded measurement uncertainty of less than5% (k = 2). Within the project, a Supplementary comparison of calibration factors in terms of ambient dose equivalent will be conducted. This comparison will help to validate the capabilities that the partners developed during and before the project and will help emerging institutes gain international recognition. The comparison will cover both radionuclide and x-ray radiation qualities according to ISO 4037-1.Proceedings: [http://vinar.vin.bg.ac.rs/handle/123456789/8681]XXX симпозијум ДЗЗСЦГ (Друштва за заштиту од зрачења Србије и Црне Горе), 2- 4. октобар 2019. године, Дивчибаре, Србиј

Determination of uniformity and field size of reference X-ray beams

Cilj ovog rada je da se ispita uniformnost i veličina referentnog polja generisanog pomoću generatora X-zračenja. U tu svrhu je koriššena jonizaciona komora male zapremine tako što su mapirane jačine doze. Na osnovu merenja, određen je korekcioni faktor za neuniformnost polja zračenja. Rezultati prikazani u ovom radu se odnose na polje kolimisano pomoću aperture prečnika 4,2 cm i generisano pomoću generatora X-zračenja konstantnog napona i struje. Ispitivanje je izvršeno u kvalitetu zračenja koji se koristi u dijagnostičkoj radiologiji, ali je ova procedura takođe primenjiva i na kvalitete koji se koriste za etaloniranje uređaja za zaštitu od zračenja definisane u novoj verziji ISO 4037 iz 2019. godine.The aim of this paper is to study the uniformity and the size of a reference radiation field produced by an x-ray generator. This work uses a technique to map dose distribution and measure dose rates with a small-volume spherical ionization chamber in order to determine the correction factor for non uniformity of the radiation field. Results shown in this paper are profile measurementsperformed in radiation beam collimated by a 4.2 cm diameter aperture, generated by calibration x-ray equipment of constant voltage and current. Thestudy was conducted in a diagnostic radiology radiation quality, but this procedure is also applicable to the new revised version of ISO 4037 standard from 2019 which specifies protection level reference radiation qualities.Proceedings: [http://vinar.vin.bg.ac.rs/handle/123456789/8681]XXX симпозијум ДЗЗСЦГ (Друштва за заштиту од зрачења Србије и Црне Горе), 2- 4. октобар 2019. године, Дивчибаре, Србиј

EURAMET Dosetrace projekat i dodatna interkomparacija

Accurate and traceable measurements of operational quantities are required for adequate radiation protection. National Measurement Institutes (NMI) and Designated Institutes (DI) are responsible for disseminating the SI unit sievert and for calibrating user equipment. However, in many emerging European countries, calibration and measurement capabilities for operational quantities are limited or nonexistent. The main objective of DOSEtrace project is to improve these capabilities and for the participants to achieve the expanded measurement uncertainty of less than 5% (k = 2). Within the project, a Supplementary comparison of calibration factors in terms of ambient dose equivalent will be conducted. This comparison will help to validate the capabilities that the partners developed during and before the project and will help emerging institutes gain international recognition. The comparison will cover both radionuclide and x-ray radiation qualities according to ISO 4037-1.Taţna i sledljiva merenja operativnih veliţina su neophodna za adekvatnu zaštitu od zraţenja. Nacionalni metrološki instituti i Imenovani instituti su zaduţeni za diseminaciju SI jedinice Sivert i za etaloniranje korisniţke opreme. Ipak, u velikom broju Evropskih zemalja, mogušnosti etaloniranja za operativne veliţine su nedovoljno razvijene ili nepostoješe. Glavni cilj DOSEtrace projekta je unapreŤenje ovih mogušnosti, kao i smanjenje proširene merne nesigurnosti uţesnika projekta ispod 5 % (k = 2). U okviru projekta še biti sprovedena Dodatna interkomparacija kalibracionih faktora za ambijentalni dozni ekvivalent. Ova interkomparacija še pomoši uţesnicima projekta da validiraju merne mogušnosti razvijene pre i tokom projekta, a takoŤe še pomoši novim institutima da steknu meŤunarodno priznanje. U okviru intercomparacije, biše pokriveni kvaliteti zraţenja radionuklida, kao i x-zraţenja.XXX симпозијум ДЗЗСЦГ (Друштва за заштиту од зрачења Србије и Црне Горе), 2-4. октобар 2019. годин

EURAMET i DOSEtrace project and supplementary comparison

Tačna i sledljiva merenja operativnih veličina su neophodna za adekvatnu zaštitu od zračenja. Nacionalni metrološki instituti i Imenovani instituti su zaduženi za diseminaciju SI jedinice Sivert i za etaloniranje korisničke opreme. Ipak, u velikom broju Evropskih zemalja, mogušnosti etaloniranjaza operativne veličine su nedovoljno razvijene ili nepostoješe. Glavni cilj DOSEtrace projekta je unapređenje ovih mogućnosti, kao i smanjenje proširene merne nesigurnosti učesnika projekta ispod 5 % (k = 2). U okviru projekta še biti sprovedena Dodatna interkomparacija kalibracionih faktora za ambijentalni dozni ekvivalent. Ova interkomparacija še pomoši učesnicima projekta da validiraju merne mogušnosti razvijene pre i tokom projekta, a takođe će pomoći novim institutima da steknu međunarodno priznanje. U okviru intercomparacije, biše pokriveni kvaliteti zračenja radionuklida, kao i x-zračenja.Accurate and traceable measurements of operational quantities are required for adequate radiation protection. National Measurement Institutes (NMI) and Designated Institutes (DI) are responsible for disseminating the SI unit sievert and for calibrating user equipment. However, in many emerging European countries, calibration and measurement capabilities for operational quantities are limited or nonexistent. The main objective of DOSEtrace project is to improve these capabilities and for the participants to achieve the expanded measurement uncertainty of less than5% (k = 2). Within the project, a Supplementary comparison of calibration factors in terms of ambient dose equivalent will be conducted. This comparison will help to validate the capabilities that the partners developed during and before the project and will help emerging institutes gain international recognition. The comparison will cover both radionuclide and x-ray radiation qualities according to ISO 4037-1.Proceedings: [http://vinar.vin.bg.ac.rs/handle/123456789/8681]XXX симпозијум ДЗЗСЦГ (Друштва за заштиту од зрачења Србије и Црне Горе), 2- 4. октобар 2019. године, Дивчибаре, Србиј

Comparison of calibration factors for field-class dosimeters

This paper presents a comparison performed between two calibration laboratories in several radiation qualities, using dosimeters of varying quality as transfer instruments. The goal of this work was to investigate the viability of using field-class dosimeters for official comparisons and to determine if the calibration factors for field-class dosimeters are comparable between calibration laboratories within the stated measurement uncertainties. The results of the comparison were acceptable for high-quality electronic personal dosimeters in all radiation qualities, and such dosimeters could be used as transfer instruments. On the other hand, comparison results for low-quality dosimeters were often not acceptable, either due to pronounced energy dependence, low stability, or both. Such instruments are unreliable even under well-defined laboratory conditions, and their use in routine measurements may cause doubt in official data or influence public opinion. This problem is often hidden because many dosimeters are calibrated or verified only in 137Cs beams, where the deviations are the smallest. The largest differences are found for low-energy X-ray radiation qualities, where many dosimeters have significant overresponse

Uticaj spektara referentnih polja na etaloniranje korisničkih dozimetara

Active electronic dosimeters are usually calibrated in Secondary Standards Dosimetry Laboratories in reference photon fields, with the uncertainty which is typically around 5 % (k=2). Reference fields are established in accordance with relevant international standards – usually ISO 4037 for photon radiation. Some differences in spectra between different laboratories are unavoidable, but the effect on reference dose rates is well studied and within the above mentioned measurement uncertainty, and this is confirmed by existing interlaboratory comparisons. However, many field class dosimeters have poor energy dependence, especially in the energy range below 100 keV, which could cause large differences in calibration factors determined in different calibration laboratories under nominally the same conditions. This may also have implications for dosimeter testing or verification. In this paper, preliminary results obtained in two different calibration laboratories are presented.Aktivni elektronski dozimetri se najčešće etaloniraju u Sekundarnim standardnim dozimetrijskim laboratorijama u referentnim poljima fotonskog zračenja, sa mernom nesigurnošću od oko 5 % (k=2). Referentna polja se uspostavljaju u skladu sa međunarodnim standardima, obično ISO 4037 za fotonsko zračenje. Male razlike u spektrima u različitim laboratorijama su neizbežne, ali je efekat na referentne vrednosti dobro proučen i ostaje u okviru mernih nesigurnosti, što je potvrđeno postojećim međulaboratorijskim poređenjima. Međutim, mnogi korisnički dozimetri imaju lošu energetsku zavisnost, pogotovo u opsegu energija ispod 100 keV, što može da uzrokuje velike razlike u kalibracionim faktorima određenim u različitim laboratorijama u nominalno istim uslovima. To može da ima posledice i na ispitivanje ili overavanje dozimetara. U ovom radu su prikazani prvi rezultati dobijeni u dve različite laboratorije za etaloniranje.XXXI Симпозијум Друштва за заштиту од зрачења Србије и Црне Горе, 06-08. октобар 2021.Proceedings: [https://vinar.vin.bg.ac.rs/handle/123456789/9668