Changes of nuclear spectra under the influence of cosmic radiation

U ovoj disertaciji su prikazani rezultati kompleksnih istraživanja uticaja kosmičkog zračenja na nuklearne spektre na nivou mora. Utvrđivanje specifičnih vremenskih intervala u vremenskom spektru, kojima odgovaraju tačno određene grupe događaja indukovane kosmičkim mionima, omogućava adekvatno odbacivanje ometajućih događaja u željenim energetskim oblastima detektovanih spektara, pri antikoincidentnom režimu rada ultraniskofonskih sistema. U prvom eksperimentu prikazanom u ovoj disertaciji,  istraživana je mogućnost vremenskog razlaganja detektovanih događaja,  pomoću koincidentnog sistema u čijem sklopu se nalazi HPGe detektor i  plastični scintilator, u površinskoj laboratoriji. Ustanovljeno je da se promptni i zakasneli koincidentni događaji između plastičnog “veto” detektora i germanijumskog detektora mogu jasno razdvojiti u dve grupe, za oko 100 ns. Dodatno, zakočno zračenje i  anihilacioni događaji mogu se razdvojiti u vremenu od (n,n’) događaja, iako svi ovi događaji pripadaju grupi zakasnelih događaja. Takođe, registrovani su  i  značajno zakasneli anihilacioni događaji, koji nastaju usled raspada zaustavljenih pozitivnih miona. Drugi eksperiment prikazan u ovoj disertaciji baziran je na ultra-niskofonskom HPGe spektrometru relativne efikasnosti 100%. Dodatkom dva plastična scintilatora i brzo-sporog koincidentnog kola, istraživani su koincidentni događaji između plastičnih scintilatora i HPGe spektrometra. Ovaj spektrometarski sistem MIREDO (Muon Induced Rare Event Dynamic Observatory) prvenstveno je namenjen proučavanju procesa indukovanih kosmičkim mionima u različitim materijalima. Analiza ovakvih interakcija može biti od značaja za ultra-niskofonske eksperimente. Rezultati dobijeni za tri ispitivana materijala, pakovana u Marinelli sud, prezentovani su i diskutovani. U trećem eksperimentu prikazanom u ovoj disertaciji ispitan je potencijalni uticaj solarnih  neutrina  na izmerenu brzinu  radioaktivnog raspada,  merenjem varijacija u brzini brojanja 3H  metodom tečnog scintilacionog brojanja. Korišćenjem sofisticiranog tečnog scintilacionog spektrometra  Quantulus  ustanovljeno je da na merenje visokoenergetskog dela 3H spektra može značajno uticati nestabilnost instrumenta. Oscilatorni karakter izmerenog visokoenergetskog dela 3H spektra  je registrovan, ali sa veoma malom amplitudom (manjom od 0.5%), koja se ne može jednostavno objasniti samo nestabilnošću instrumenta.  Kada je meren ukupan 3H spektar, nisu nađene značajne varijacije u brzini brojanja. Već duže vreme je poznato da je niskoenergetsko gama zračenje kontinualne distribucije prisutno na otvorenom prostoru, u vazduhu na površini Zemlje. U prethodnim istraživanjima pretpostavljano je da  ovo zračenje potiče skoro isključivo od gama fotona koji su emitovani usled prirodne radioaktivnosti i potom rasejani u nazad od strane vazduha iznad zemlje. U četvrtom eksperimentu prikazanom u ovoj disertaciji pokazano je da  je  ovo zračenje (u energetskom regionu 30 keV-300 keV), sa maksimumom na oko  90 keV, u značajnoj meri  proizvedeno kosmičkim zračenjem, sa fluksom fotona od oko 3000 m-2s-1. Takođe, ustanovljeno je da dozama opšte populacije doprinosi ovo sveprisutno niskoenergetsko gama zračenja kosmičkog porekla, zajedno sa odgovarajućim fluksom niskoenergetskih elektrona i da ove komponente ukupnih doza indukovanih kosmičkim zračenjem na nivou mora nisu zanemarljive.In this dissertation results of complex research on cosmic-ray impact on nuclear spectra at sea level are shown.  The appropriate selection of coincidence time interval  in low-background experiments that are based on the rejection of anticoincidence background events is very important for reducing the influence of cosmic-ray muons on acquired spectral data. In  the first  experiment  presented in this dissertation,  performed by the coincidence system of an HPGe detector and a plastic detect or  in a surface laboratory, the time resolution of the detected events is explored. It is  found that the prompt and delayed coincidence events between a plastic veto detector and a  Ge detector can be sharply divided for approximately 100 ns in two groups. In addition, the bremsstrahlung and annihilation events can  be time-resolved from the (n,n’) events, although all of these events belong to the group of delayed events. Also, substantially delayed annihilation events, which are caused by the  decays of stopped positive muons, were detected. The second experiment shown in this dissertation is based on the 100% relative efficiency ultra-low-background HPGe spectrometer. With the addition of two plastic scintillators and a fast-slow coincidence circuit, the coincidence events between the plastic detectors and the HPGe spectrometer have been investigated. This  MIREDO (Muon Induced Rare Event Dynamic Observatory) spectrometer system is primarily  developed for the study of cosmic muon induced processes in different materials. Exploration of such interactions can be important for ultra-low background experiments. Results derived for three samples, placed in a Marinelli beaker, are presented and discussed. In third experiment shown in this dissertation,  the potential influence of solar neutrinos on measured decay rate is investigated by  the liquid scintillation measurement of the count rate variations of 3H. Making use of the sophisticated Quantulus liquid scintillation spectrometer, it is found that the  measurement of the high-energy tail of 3H spectrum may be significantly influenced by instrumental  instability.  The oscillatory behavior of measured high-energy tail of 3H spectrum  is registered, but with very small amplitude (less than 0.5%), which cannot  be easily  explained only by instrumental instability. When the total 3H spectrum was measured, no significant variations in the count rate were found.  For a long time, it has been known that low-energy continuous gamma radiation is present in open air at the Earth’s surface. In previous investigations it was assumed that this radiation is produced almost exclusively by gamma photons emitted due to the natural radioactivity, which are backscattered by air above ground.  In the fourth experiment presented in this dissertation, it is  shown  that significant amount of this  radiation (related to energy region 30  keV-300  keV) that peaks at about 90 keV, is produced by cosmic-rays, with the photon flux of about 3000 m-2s-1.  Also, it is found  that the contribution of this omnipresent low energy gamma radiation of cosmic-ray origin, including the corresponding low-energy electron flux, to the doses of general  population are non-negligible components of overall doses induced by cosmic rays near sea level

Changes of nuclear spectra under the influence of cosmic radiation

U ovoj disertaciji su prikazani rezultati kompleksnih istraživanja uticaja kosmičkog zračenja na nuklearne spektre na nivou mora. Utvrđivanje specifičnih vremenskih intervala u vremenskom spektru, kojima odgovaraju tačno određene grupe događaja indukovane kosmičkim mionima, omogućava adekvatno odbacivanje ometajućih događaja u željenim energetskim oblastima detektovanih spektara, pri antikoincidentnom režimu rada ultraniskofonskih sistema. U prvom eksperimentu prikazanom u ovoj disertaciji,  istraživana je mogućnost vremenskog razlaganja detektovanih događaja,  pomoću koincidentnog sistema u čijem sklopu se nalazi HPGe detektor i  plastični scintilator, u površinskoj laboratoriji. Ustanovljeno je da se promptni i zakasneli koincidentni događaji između plastičnog “veto” detektora i germanijumskog detektora mogu jasno razdvojiti u dve grupe, za oko 100 ns. Dodatno, zakočno zračenje i  anihilacioni događaji mogu se razdvojiti u vremenu od (n,n’) događaja, iako svi ovi događaji pripadaju grupi zakasnelih događaja. Takođe, registrovani su  i  značajno zakasneli anihilacioni događaji, koji nastaju usled raspada zaustavljenih pozitivnih miona. Drugi eksperiment prikazan u ovoj disertaciji baziran je na ultra-niskofonskom HPGe spektrometru relativne efikasnosti 100%. Dodatkom dva plastična scintilatora i brzo-sporog koincidentnog kola, istraživani su koincidentni događaji između plastičnih scintilatora i HPGe spektrometra. Ovaj spektrometarski sistem MIREDO (Muon Induced Rare Event Dynamic Observatory) prvenstveno je namenjen proučavanju procesa indukovanih kosmičkim mionima u različitim materijalima. Analiza ovakvih interakcija može biti od značaja za ultra-niskofonske eksperimente. Rezultati dobijeni za tri ispitivana materijala, pakovana u Marinelli sud, prezentovani su i diskutovani. U trećem eksperimentu prikazanom u ovoj disertaciji ispitan je potencijalni uticaj solarnih  neutrina  na izmerenu brzinu  radioaktivnog raspada,  merenjem varijacija u brzini brojanja 3H  metodom tečnog scintilacionog brojanja. Korišćenjem sofisticiranog tečnog scintilacionog spektrometra  Quantulus  ustanovljeno je da na merenje visokoenergetskog dela 3H spektra može značajno uticati nestabilnost instrumenta. Oscilatorni karakter izmerenog visokoenergetskog dela 3H spektra  je registrovan, ali sa veoma malom amplitudom (manjom od 0.5%), koja se ne može jednostavno objasniti samo nestabilnošću instrumenta.  Kada je meren ukupan 3H spektar, nisu nađene značajne varijacije u brzini brojanja. Već duže vreme je poznato da je niskoenergetsko gama zračenje kontinualne distribucije prisutno na otvorenom prostoru, u vazduhu na površini Zemlje. U prethodnim istraživanjima pretpostavljano je da  ovo zračenje potiče skoro isključivo od gama fotona koji su emitovani usled prirodne radioaktivnosti i potom rasejani u nazad od strane vazduha iznad zemlje. U četvrtom eksperimentu prikazanom u ovoj disertaciji pokazano je da  je  ovo zračenje (u energetskom regionu 30 keV-300 keV), sa maksimumom na oko  90 keV, u značajnoj meri  proizvedeno kosmičkim zračenjem, sa fluksom fotona od oko 3000 m-2s-1. Takođe, ustanovljeno je da dozama opšte populacije doprinosi ovo sveprisutno niskoenergetsko gama zračenja kosmičkog porekla, zajedno sa odgovarajućim fluksom niskoenergetskih elektrona i da ove komponente ukupnih doza indukovanih kosmičkim zračenjem na nivou mora nisu zanemarljive.In this dissertation results of complex research on cosmic-ray impact on nuclear spectra at sea level are shown.  The appropriate selection of coincidence time interval  in low-background experiments that are based on the rejection of anticoincidence background events is very important for reducing the influence of cosmic-ray muons on acquired spectral data. In  the first  experiment  presented in this dissertation,  performed by the coincidence system of an HPGe detector and a plastic detect or  in a surface laboratory, the time resolution of the detected events is explored. It is  found that the prompt and delayed coincidence events between a plastic veto detector and a  Ge detector can be sharply divided for approximately 100 ns in two groups. In addition, the bremsstrahlung and annihilation events can  be time-resolved from the (n,n’) events, although all of these events belong to the group of delayed events. Also, substantially delayed annihilation events, which are caused by the  decays of stopped positive muons, were detected. The second experiment shown in this dissertation is based on the 100% relative efficiency ultra-low-background HPGe spectrometer. With the addition of two plastic scintillators and a fast-slow coincidence circuit, the coincidence events between the plastic detectors and the HPGe spectrometer have been investigated. This  MIREDO (Muon Induced Rare Event Dynamic Observatory) spectrometer system is primarily  developed for the study of cosmic muon induced processes in different materials. Exploration of such interactions can be important for ultra-low background experiments. Results derived for three samples, placed in a Marinelli beaker, are presented and discussed. In third experiment shown in this dissertation,  the potential influence of solar neutrinos on measured decay rate is investigated by  the liquid scintillation measurement of the count rate variations of 3H. Making use of the sophisticated Quantulus liquid scintillation spectrometer, it is found that the  measurement of the high-energy tail of 3H spectrum may be significantly influenced by instrumental  instability.  The oscillatory behavior of measured high-energy tail of 3H spectrum  is registered, but with very small amplitude (less than 0.5%), which cannot  be easily  explained only by instrumental instability. When the total 3H spectrum was measured, no significant variations in the count rate were found.  For a long time, it has been known that low-energy continuous gamma radiation is present in open air at the Earth’s surface. In previous investigations it was assumed that this radiation is produced almost exclusively by gamma photons emitted due to the natural radioactivity, which are backscattered by air above ground.  In the fourth experiment presented in this dissertation, it is  shown  that significant amount of this  radiation (related to energy region 30  keV-300  keV) that peaks at about 90 keV, is produced by cosmic-rays, with the photon flux of about 3000 m-2s-1.  Also, it is found  that the contribution of this omnipresent low energy gamma radiation of cosmic-ray origin, including the corresponding low-energy electron flux, to the doses of general  population are non-negligible components of overall doses induced by cosmic rays near sea level

Applying of Monte-Carlo simulations for in-situ gamma spectrometry

Kako bi se dobile krive efikasnosti detekcije za In-situ merenja gama zračenja poreklom iz zemljišta, potrebno je izvršiti odgovarajuće Monte-Karlo simulacije. U simulacijama je korišćena gustina zemljišta od 1,046 g/cm3 , dok je elementalni sastav zemljišta u kojem se generiše gama zračenje bio: O - 47%, Si - 35%, Al - 8%, Fe – 3,9%, C – 2,1%, Ca – 1,4%, K – 1,3%, N – 0,6%, Mg – 0,6%, N – 0,1%. Matrica zemljišta je predstavljena cilindričnom zapreminom prečnika 1,5 m i debljine 0,5 m, iznad koje je na visini od 1 m postavljen germanijumski detektor. Razmatrane su homogene distribucije različitih radionuklida (Ra-226, Th-232, K-40) u matrici zemljišta. U simulacijama su dobijeni i analizirani odgovarajući gama spektri, koji uz podatke o simuliranim efikasnostima detekcije, omogućuju poređenje sa realnim eksperimentalnim merenjima i praktičnu primenu simulacionih rezultata.In this work, the Monte-Carlo simulations for In-Situ gamma spectrometry of soil were performed. The simulated gamma spectrum, originated from K-40, as well as from members of Th-232 chain, and daughters of Ra-226, was obtained. We obtained the corresponding detection efficiency curve for HPGe detector, which can be applied for In-Situ measurement of radionuclide concentration in soil, assuming uniform radionuclide distribution.Зборник радова : XXIX симпозијум ДЗЗСЦГ : Сребрно језеро, 27-29. септембар 2017. годин

Applying of Monte-Carlo simulations for in-situ gamma spectrometry

Kako bi se dobile krive efikasnosti detekcije za In-situ merenja gama zračenja poreklom iz zemljišta, potrebno je izvršiti odgovarajuće Monte-Karlo simulacije. U simulacijama je korišćena gustina zemljišta od 1,046 g/cm3 , dok je elementalni sastav zemljišta u kojem se generiše gama zračenje bio: O - 47%, Si - 35%, Al - 8%, Fe – 3,9%, C – 2,1%, Ca – 1,4%, K – 1,3%, N – 0,6%, Mg – 0,6%, N – 0,1%. Matrica zemljišta je predstavljena cilindričnom zapreminom prečnika 1,5 m i debljine 0,5 m, iznad koje je na visini od 1 m postavljen germanijumski detektor. Razmatrane su homogene distribucije različitih radionuklida (Ra-226, Th-232, K-40) u matrici zemljišta. U simulacijama su dobijeni i analizirani odgovarajući gama spektri, koji uz podatke o simuliranim efikasnostima detekcije, omogućuju poređenje sa realnim eksperimentalnim merenjima i praktičnu primenu simulacionih rezultata.In this work, the Monte-Carlo simulations for In-Situ gamma spectrometry of soil were performed. The simulated gamma spectrum, originated from K-40, as well as from members of Th-232 chain, and daughters of Ra-226, was obtained. We obtained the corresponding detection efficiency curve for HPGe detector, which can be applied for In-Situ measurement of radionuclide concentration in soil, assuming uniform radionuclide distribution.Зборник радова : XXIX симпозијум ДЗЗСЦГ : Сребрно језеро, 27-29. септембар 2017. годин

Extending and Enhancing the Existing Motorail (Car Trains) System in the Danube River Basin (Drb)

The aim of the project is the enhancement of a greener, innovative and sustainable mobility through the extension of the existing railway system with as little changes as possible and the development of new modes of transport, providing a fast and seamless combination of rail and water transport, followed by short distance travel to the final destination by motorized vehicles or bicycles. This would be achieved through the extension in the Danube River Basin of the motorail system which allows the transport of cars, motorbikes and small trailers, creating an efficient, seamless and low-carbon transport network, thus contributing to the sustainable development of economic competitiveness and growth, of an integrated European single market and of an open and inclusive society, of tourist accessibility to new countries

Investigations of possible correlations between radionuclides content and geochemical characteristics of Vojvodina soil

U ovom rаdu prikazani su rezultati istraživanja moguće korelаcije geohemijskih kаrаkteristikа zemljišta i sadržaja prirodnih rаdionuklida 238U, 226Ra, 232Th i 40K, kаo i radionuklida antropogenog porekla 137Cs u svim geomorfološkim jedinicama zemljišta na području Vojvodine. Tokom 2001. godine izvršen je detaljan monitoring radioaktivnosti zemljišta na 50 odabranih lokacija prema tipu zemljišta sa analizom mehaničkog sastava zemljišta i sadržaja humusa i pristupačnog fosfora i kalijuma. Kako bi se ispitao potencijаlni uticаj obrаde poljoprivrednog zemljišta i vremenskih uslovа nа migrаciju i distribuciju rаdionuklidа prisutnih u zemljištu, monitoring zemljišta je na istim lokacijama ponovljen 2010. godine. Glavni zaključak ovih istraživanja je da izmerene maksimalne koncentracije aktivnosti radionuklida: 238U (87 Bq/kg), 226Ra (44,7 Bq/kg), 232Th (55,5 Bq/kg) i 137Cs (29 Bq/kg) u profilu zemljišta dubine 30 cm ne ugrožavaju bezbednost proizvodnje hrane na ovom zemljištu. Utvrđena je najveća zavisnost koncentracije aktivnosti kalijuma 40K od sadržaja gline u poljoprivrednom zemljištu.In this paper, we performed, for the first time, detailed study of Vojvodina’s soil in order to explore possible correlations of soil geochemical characteristics and radionuclide activity concentrations. The aim of this study is to analyze the content of natural radioisotopes 238U, 226Ra, 232Th and 40K, as well as artificial radioisotope 137Cs in all soil types originated from the same parent material – loess. The sampling locations were selected so that they are proportionately represented all geomorphological units: two mountains, four loess plateaus, three loess terraces, four alluvial plains, two sandstone terrains. The process of genesis of soil and cultivation mode plays a dominant role on the characteristics of the soil. However intensive agricultural production and the use of high mineral fertilizers have caused that the same type of soil contains different concentrations of available phosphorus and radionuclides. Comparison of activity concentrations between different types of soil confirmed that the presence of clay mostly contributes to radionuclides content in the soil. The main conclusion is that measured maximal activity concentrations for 238U (87 Bq/kg), 226Ra (44.7 Bq/kg), 232Th (55.5 Bq/kg) and 137Cs (29 Bq/kg) at 30 cm depth could not endanger the safety of food production

Results of the 2015 national indoor radon intercomparison measurements in Serbia

Results and conclusions of interlaboratory comparison of indoor radon in 2015 in Serbia are presented. The participants were three accredited laboratories from Serbia: Serbian Institute of Occupational Health Dr Dragomir Karajovic, Laboratory for Radioactivity and Dose Measurements at the Faculty of Sciences, University of Novi Sad and Radiation and Environmental Protection Department, Vinca Institute of Nuclear Science. The laboratories make use of the same method for radon measurement, using charcoal canisters according to US Environmental Protection Agency (EPA) protocol 520/5-87-005. Calibration of detection efficiency was performed using EPA radium standard. Radon activity concentrations were determined on the basis of the intensity of short-living radon daughters, Bi-214 and Pb-214, gamma lines. The results of intercomparison were evaluated by using the u-test, which was calculated according to the International Atomic Energy Agency criteria. In this paper, not only limitations but also the advantages and possibilities of application of this method for measuring levels of human exposure to radon are discussed

Multivariate analysis application for geogeny radon potential prediction

Geogeni radonski potencijal koji izdvaja radon u podzemnim slojevima kao dominantan uzrok akumulacije radona u zatvorenim prostorijama i koji je nezavisan od ljudskog uticaja i vremenski konstantan u geološkim okvirima predstavlja glavni alat za iznalaženje radonom ugroženih područja. U nedostatku podataka za permeabilnost zemljišta za radon i malog broja merenja radona u zemljištu, upotrebljena je multivarijantna analiza velikog broja raspoloživih geohemijskih podataka, merenja radioaktivnosti zemljišta i koncentracija aktivnosti radona u zatvorenim prostorijama datih lokacija na području Vojvodine. Nekoliko uporedivih metoda iz ROOT okvira za analize softverskog paketa TMVA je korišćeno za analizu zavisnosti koncentracije radona u zatvorenom od mnoštva ulaznih varijabli. BDTG kao najpodobnija metoda je pokazala da su varijable sa najvećim uticajem na koncentraciju radona u zatvorenim prostorijama pored sadržaja ukupnog azota, koncentracije aktivnosti radionuklida u zemljištu na profilu dubine od 30 cm i sadržaj humusa i gline. Dobijeni rezultati pokazuju dobro slaganje sa nedavnim ispitivanjem emanacije radona iz zemljišta na području grada Novog Sada.The most dominant source of indoor radon is the underlying soil, so the enhanced levels of radon are usually expected in mountain regions and geology units with high radium and uranium content in surface soils. Laboratory for radioactivity and dose measurement, Faculty of Sciences, University of Novi Sad has rich databases of natural radionuclides concentrations in Vojvodina soil and also of indoor radon concentrations for the region of Vojvodina, Northern Province of Serbia. In this paper, we present the results of correlative and multivariate analysis of these results and geochemical characteristics of soil in order to estimate the geogenic radon potential. The correlative and multivariate analysis were done using Toolkit for Multivariate Analysis software package TMVA package, which uses several comparable multivariate methods for our analysis. The evaluation ranking results based on the best signal efficiency and purity, show that the Boosted Decision Trees (BDT) and Multi Layer Preceptor (MLP), based on Artificial Neural Network (ANN), are multivariate methods which give the best results in the analysis. The BDTG multivariate method shows that variables with the highest importance are radio-nuclides activity on 30 cm depth. Moreover, the multivariate regression methods give a good approximation of radon activity using full set of input variable

Multivariate analysis application for geogeny radon potential prediction

Geogeni radonski potencijal koji izdvaja radon u podzemnim slojevima kao dominantan uzrok akumulacije radona u zatvorenim prostorijama i koji je nezavisan od ljudskog uticaja i vremenski konstantan u geološkim okvirima predstavlja glavni alat za iznalaženje radonom ugroženih područja. U nedostatku podataka za permeabilnost zemljišta za radon i malog broja merenja radona u zemljištu, upotrebljena je multivarijantna analiza velikog broja raspoloživih geohemijskih podataka, merenja radioaktivnosti zemljišta i koncentracija aktivnosti radona u zatvorenim prostorijama datih lokacija na području Vojvodine. Nekoliko uporedivih metoda iz ROOT okvira za analize softverskog paketa TMVA je korišćeno za analizu zavisnosti koncentracije radona u zatvorenom od mnoštva ulaznih varijabli. BDTG kao najpodobnija metoda je pokazala da su varijable sa najvećim uticajem na koncentraciju radona u zatvorenim prostorijama pored sadržaja ukupnog azota, koncentracije aktivnosti radionuklida u zemljištu na profilu dubine od 30 cm i sadržaj humusa i gline. Dobijeni rezultati pokazuju dobro slaganje sa nedavnim ispitivanjem emanacije radona iz zemljišta na području grada Novog Sada.The most dominant source of indoor radon is the underlying soil, so the enhanced levels of radon are usually expected in mountain regions and geology units with high radium and uranium content in surface soils. Laboratory for radioactivity and dose measurement, Faculty of Sciences, University of Novi Sad has rich databases of natural radionuclides concentrations in Vojvodina soil and also of indoor radon concentrations for the region of Vojvodina, Northern Province of Serbia. In this paper, we present the results of correlative and multivariate analysis of these results and geochemical characteristics of soil in order to estimate the geogenic radon potential. The correlative and multivariate analysis were done using Toolkit for Multivariate Analysis software package TMVA package, which uses several comparable multivariate methods for our analysis. The evaluation ranking results based on the best signal efficiency and purity, show that the Boosted Decision Trees (BDT) and Multi Layer Preceptor (MLP), based on Artificial Neural Network (ANN), are multivariate methods which give the best results in the analysis. The BDTG multivariate method shows that variables with the highest importance are radio-nuclides activity on 30 cm depth. Moreover, the multivariate regression methods give a good approximation of radon activity using full set of input variable

Radioactivity Measurements of Ceramic Tiles Produced in Serbia

This paper presents the results of gamma spectrometry measurements of natural radionuclides ( 226Ra, 232Th, and 40K) in some floor and wall ceramic tiles produced in Serbia and used in homes and workplaces. The level of radioactivity of some ceramic tiles produced in Serbia by two major manufacturers–Zorka Keramika and Toza Markovic was examined. The measured mean value of the activity concentration of 226Ra, 232Th, and 40K exceeds the average values in the world for building materials with values of 67.2±6.9 Bq kg-1 for 226Ra, 57.4±4.7 Bq kg-1 for 232Th and 808±48 Bq kg-1 for 40K. Based on these calculated values, the representative level index gamma index, associated with gamma radiation, whose average value is 0.78±0.06, and annual effective dose, whose average value is 0.117±0.009 mSv y-1 for home was obtained. Estimated values fulfill all the recommendations of the European Union for building materials, thus analyzed materials are considered not to be a health hazard for the public.BPU11 : 11th International Conference of the Balkan Physical Union : Proceedings book; Aug 11 - Sep 1, 2022S01-NPNE Nuclear Physics and Nuclear Energ