Introducing a Novel Beta-ray Detector Based on Polycarbonate/ Bismuth Oxide Nanocomposite: Simulation and Experiment

Introducing a Novel Beta-ray Detector Based on Polycarbonate/ Bismuth Oxide Nanocomposite: Simulation and Experiment | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Introducing a Novel Beta-ray Detector Based on Polycarbonate/ Bismuth Oxide Nanocomposite: Simulation and Experiment Seyed Musa Safdari, Shahryar Malekie, Sedigheh Kashian, Morteza Akbari This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-1043040/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 8 You are reading this latest preprint version Abstract In this research, for the first time, the detection response of Polycarbonate/Bismuth oxide composite to a pure beta-emitter 90 Sr with two energies of 546.2 keV, and 2.28 MeV is studied. Firstly, the range and stopping power of the electrons of 90 Sr in the composite at various concentrations of 0, 10, 20, 30, 40 and 50 wt% were calculated using the ESTAR program. Results of simulation demonstrated that the concentration of the heavy metal oxide particles into the polymer matrix played an important role to evaluate the range and stopping power of the electrons in the composite. Secondly, at the experimental phase, the sample of 50 wt% composite with dimensions of 4 cm×4 cm×0.1 cm 3 was prepared. Afterwards, the sample was irradiated by 90 Sr and the amount of electric current was measured using an electrometer at voltages of 100-1000 V. Additionally, the I-V plot exhibited a linear response at different voltages in the fixed source surface distance. Results of this study showed that this composite can serve as a novel beta detector. Nuclear Medicine & Medical Imaging Beta Detector PC-Bi2O3 nanocomposite Dose Rate Strontium-90 ESTAR Program Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 1. Introduction Detection and dosimetry of ionizing radiation are of important issues in the nuclear industry. Recently, polymer-nanocomposites have been used as radiation sensors, detectors, dosimeters, and shielding materials [ 1-15 ]. The mechanisms of interaction of beta particles with matter is categorized in two sections, electron excitation and ionization, in which electrons interact with the particles traversing the material via the Coulomb electric field [ 16-18 ]. Electrons lose their energy by friction attributed to the CSDA, or continuous slowing-down approximation [ 19-21 ]. The collisions of electrons with the particles are including hard collisions or inelastic scattering with orbital electrons produces excitation or ionization of electrons, and secondary electrons, inelastic scattering with nuclei leads to produce Bremsstrahlung, and soft collisions or elastic scattering, in which electrons lose a small fraction of their energies [ 16 ]. Some radioisotopes decay via beta-minus emission producing the fast electrons [ 22 ]. Several pure beta-emitters are 3 H (18.6 keV), 14 C (156 keV), 32 P (1.71 MeV), 33 P (248 keV), 35 S (167 keV), 36 Cl (714 keV), 345 Ca (252 keV), 63 Ni (67 keV), 90 Sr/ 90 Y (546 keV/2.27 MeV), 147 Pm (224 keV), and 204 Tl (766 keV) [ 22 ].Various types of scintillators are commonly used to detect beta-rays. In addition, low Z materials including organic polymers are excellent absorbers of charged particles such as beta-rays, which will provide high sensitivity for charged particle detection [ 20 , 23-26 ]. A disadvantage of some scintillators and gas-flow type proportional counters is limitations due to their hygroscopicity, and scalability [ 26 ]. The main purpose of this research is to design and fabricate of a novel beta solid-state detector to measure the dose rate of beta-emitter sources in real-time. The material used is new in its kind and uses Polycarbonate/Bismuth oxide (PC-Bi 2 O 3 ) composite. The reason for choosing polycarbonate as a polymer matrix is that PC is essentially an amorphous polymer that is expected to have a more suitable bond with bismuth oxide nanoparticles, because the crystalline regions of the polymer often repel nanoparticles, so the nanoparticles are dispersed in amorphous regions. In general, a polymer is composed of two crystalline and amorphous phases in terms of molecular structure. In the crystalline phase, the crystals are arranged in regular polymer chains called lamellae with a length of 20-60 nm and a distance of 0.736 nm from each other [ 27 ]. Since in this research, Bi 2 O 3 fillers with the sizes of 90-210 nm are used, so the probability of Bi 2 O 3 nanoparticles entering the crystalline region of the polymer is very low and these particles tend to be placed in the amorphous part and the amount of polymer crystallinity increases through the nucleation process. Therefore, the possibility of increasing the crystallinity of polycarbonate is enhanced by adding Bi 2 O 3 nanoparticles to it. For the PC-Bi 2 O 3 composite detector, the amount of sensitivity or minimum detectable dose rate (MDDR) for the detection of beta-rays can be controlled via heavy metal oxide inclusions into the polymer matrix. Generally, various factors affect the detector response, including polymer crystallinity, the weight percentage of metal oxide nanoparticles, nanocomposite thickness and other factors. Also, the homogeneous dispersion of metal oxide nanoparticles into the polymer matrix plays an important role in the detection response of this material. The selection of suitable thickness for a solid detector, considering the charge particle equilibrium (CPE) is a key factor in the radiation ionizing detection. So, calculation of range and stopping power of electrons at different energies and weight fractions of the inclusions in the polymer composite using the ESTAR program should be carried out. After evaluation of the electron range in the media, it is possible to calculate the exact amount of optimal detector thickness at certain energies. In this research, Strontium-90 ( 90 Sr) was chosen as a pure beta-emitter source. The 90 Sr source is generated in the reactor by the fission reaction of the 235 U nuclei as [ 28 ]: The decay mechanism of 90 Sr is as follows [ 28 ]: In which, 90 Sr decays to 90 Y with a half-life of 28.78 years, with beta particle energy of 546.2 keV; the 90 Y, which emits beta and gamma, converts to 90 Zr with a half-life of 64 hours, with beta particle energy of 2.28 MeV [ 28 ]. In this research, for the first time, a novel beta-ray detector based on PC-Bi 2 O 3 nanocomposite was introduced, and the detection response of this material was investigated theoretically and experimentally to a pure beta particle source of 90 Sr. 2. Materials And Methods 2.1 Sample preparation The PC-Bi2O3 nanocomposite at a concentration of 50 wt% was synthesized using the solution casting method. The details of the synthesis have been described in our previous work [ 1 ]. The densities of PC matrix and Bi 2 O 3 filler particles were 1.2 g/cm 3 and 8.9 g/cm 3 respectively. The average size of Bi 2 O 3 particles in the prepared material was 90-210 nm. In this experimental work, to irradiate PC-Bi 2 O 3 nanocomposite with beta-rays, a beta irradiation system model Buchler BSS-BA containing 90 Sr reference source with an initial activity of 50 mCi (production date 1978) located in Secondary Standard Dosimetry Laboratory (SSDL) Karaj-Iran was used at different source-surface distances (SSDs) according to Table 1. Also, as exhibited in Fig. 1, the Supermax Standard Imaging electrometer was used to measure the electric charge during irradiation at fixed time steps of 15 Seconds. Also, to fabricate the electrodes on two surfaces of the top and bottom of the nanocomposite, copper sheets with dimensions of 3.5 cm×3.5 cm, and 4 cm×4 cm with a thickness of 100 µm adhered to the top and bottom surfaces of the 50 wt% PC-Bi 2 O 3 nanocomposite respectively using the silver paste. Table 1. The amounts of SSDs for 90 Sr and corresponding dose rates SSD (cm) Dose Rate (mSv/h) 30 102.436 35 75.259 40 57.620 45 45.527 50 36.877 55 30.477 2.2 Simulation methodology In this research, a pure beta-emitter of 90 Sr with two energies at 546.2 keV, and 2.28 MeV was chosen for the measurements. To calculate the two key factors namely range and stopping power of the produced electrons in the composite via beta irradiation at different weight fractions of the heavy metal oxide fillers, the ESTAR program was applied [ 29 ]. The performance of any ionizing radiation detector essentially depends on the approach in which the radiation to be detected interacts with the material of the detector itself [ 22 ]. The linear stopping power for charged particles in a particular absorber is defined as the energy loss for that particle within the material divided by the corresponding path length via the Bethe-Bloch formula [ 22 ]: In which v, ze are the velocity and charge of the particles, N and Z are the number density and atomic number of the absorber atoms, m 0 is the electron rest mass, and e is the electronic charge, also I indicates to average excitation and ionization potential of the absorber material [ 22 ]. 3. Results And Discussion 3.1 FESEM analysis Fig. 2 depicts the Field Emission Scanning Electron Microscopy (FESEM) image of the prepared 50 wt% PC-Bi 2 O 3 nanocomposite. For this purpose, the FESEM device model MIRA3TESCAN-XMU was used. As can be observed in Fig. 2, a cross-sectional view of the sample showed a suitable dispersion of Bi 2 O 3 nanoparticles into the PC matrix. FESEM analysis approved the presence of the Bi 2 O 3 nanoparticles in the polymer-nanocomposite. 3.2 Results of simulation As can be seen from Fig. 3 (A, B), simulation results of the beta-emitter source of 90 Sr at two energies of 546.2 keV and 2.28 MeV for 50 wt% PC-Bi 2 O 3 composite at various weight fractions are depicted. It can be mentioned that increasing the weight fraction of the bismuth oxide particles into the polycarbonate matrix, led to a linear decrease of the range of beta particles in the composite material. This phenomenon is probably due to the increasing probability of occurring Bremsstrahlung secondary radiation by adding the Bi 2 O 3 wt% in the polymer matrix. The energy dissipation of incident beta particles via interaction with this composite material is increased by Bremsstrahlung radiation and therefore the range of the particles will be decreased subsequently. Also, according to Fig. 4, the total stopping power of electrons at various energies up to 3 MeV for PC-Bi 2 O 3 composite at different weight fractions was calculated using the ESTAR program. It can be deduced that at the specific and constant energy, with increasing the weight percentage of bismuth oxide particles in the polycarbonate matrix, the amount of stopping power of electrons in the composite will be increased. This phenomenon could be attributed to the increment of the effective atomic number of the composite in higher amounts of the reinforcement phase regarding the Bethe-Bloch formula. Results of simulation showed that the optimal thickness for detection of predominant beta particles of 546.2 keV in 90 Sr source for 50 wt% PC-Bi 2 O 3 composite was estimated to be approximately 1.2 mm. It seems that a thickness of 1 mm for this detector would be suitable for measuring beta-rays with the energy of 546 keV, and also it can be mentioned that the CPE phenomenon would be established. However, detecting the higher energy electrons including 2.28 MeV will contribute to relatively poor efficiency. To improve the efficiency of the detector, it is possible to increase the thickness of the material, nevertheless, at higher thicknesses, the applied electric field will be decreased and it will practically lose its uniformity which leads to reduced sensitivity of the detector. Thus, selecting the optimal thickness for this detector is essential. As can be seen from Fig. 5, for 50 wt% PC-Bi 2 O 3 nanocomposite, the values of photocurrent at a fixed voltage of 400 V was increased gradually from 30-75 mSv/h and finally tend to saturate afterwards at 102 mSv/h. It seems this saturation is related to the recombination of beta induced-charged particles, in which, the detection response should be measured at higher voltages. One of the most important quantities in determining the sensitivity of a detector is the signal to noise ratio. This ratio is obtained by dividing the photocurrent by the amount of dark current. The dark current and photocurrent values in the measurement phase were in the order of pA, and nA respectively. In Fig. 6, signal to noise ratio of the 50 wt% PC-Bi 2 O 3 nanocomposite for detection response to 90 Sr beta-rays is exhibited. As can be seen from Fig. 6, with increasing the amount of dose rate ranging from 30-102 mSv/h, the signal to noise ratio will be improved subsequently. This phenomenon might be pertinent to atomic displacements in the nanocomposite considering the interaction of beta particles with the atomic structures of this material. It is worth pointing out here that ionizing radiations including electrons through the interaction with the nanostructured materials, due to atomic displacement can alter the crystal structure and induce various events such as emission of secondary electrons, excitation, ionization, and bond breakage of the material atomic structures [ 30 ]. Generally, finding the suitable operating or working voltage plays an important role in radiation detectors. In Fig. 7, the I-V plot of the detector based on 50 wt% PC-Bi 2 O 3 nanocomposite in the presence of beta radiation field of 90 Sr source is exhibited, in which I is photocurrent in terms of nA which is measured by the electrometer. It is obvious from Fig. 7 that the detector response (photocurrent) is linear at various voltages range from 100 V to 1000 V. This linearity means that there is no saturation in the detector response of this nanocomposite in the aforementioned voltage range. So it is possible to choose a suitable operating voltage to achieve a significant sensitivity to detect the beta-rays efficiently. 4. Conclusion In this research, for the first time, the detection response of a novel beta-ray detector based on Polycarbonate/Bismuth Oxide composite was studied via the simulation and experiment. Firstly, at the simulation phase, the range and stopping power of electrons related to 90 Sr beta-emitter were calculated for various weight fractions of PC-Bi 2 O 3 composites up to 50 wt% using the ESTAR program. Results of simulation showed that the amount of heavy metal oxide inclusions in the polymer composite had a substantial influence on the range and stopping power quantities of electrons in the composite detector. So that, increasing the weight fraction of bismuth oxide particles in the polycarbonate matrix, led to a decrease in the range of beta particles, and increase the amount of stopping power of the composite detector linearly. So, the optimal thickness for detection of predominant beta particles of 546.2 keV in 90 Sr source for 50 wt% composite was estimated to be approximately 1.2 mm. At the experimental phase, the 50 wt% PC-Bi 2 O 3 nanocomposite was irradiated by a beta-emitter of 90 Sr source and the amount of electric current passing through the nanocomposite was measured using an electrometer at various voltages of 100-1000 V. besides, I-V plots exhibited a linear response at various voltages. Also, the measured dose rate was linear with a linear correlation coefficient of ~0.9933 ranging from 30-75 mSv/h. Results of this exploration showed that the cost-benefit Polycarbonate/Bismuth Oxide nanocomposite can be considered as a novel real-time beta detector to be used in radioactive monitoring systems for medical and industrial applications. Declarations Acknowledgements This work was extracted as part of a Master's thesis by Mr S. M. Safdari, MSc student at Islamic Azad University, Science and Research Branch, Tehran. We appreciate those who supported us in handling this research, especially the staff of NSTRI which resulted in the success of this study. Moreover, we would like to appreciate the efforts of Ms R. Mehrara and Professor S. M. Saleh Kotahi at the Physics Department, K. N. Toosi University of Technology for preparing the nanocomposite. Contributions S.M. and S.K. prepared the nanocomposite and developed the idea, S.M.S did the measurement and all authors contributed manuscript writing. Conflict of Interest The authors declare no conflict of interest. References [1] R. Mehrara, S. Malekie, S.M. Saleh Kotahi, S. Kashian, Introducing a novel low energy gamma ray shield utilizing Polycarbonate Bismuth Oxide composite, Scientific Reports, 11 (2021) 10614. [2] A. Rahimi, F. Ziaie, N. Sheikh, S. Malekie, Calorimetry System Based on Polystyrene/MWCNT Nanocomposite for Electron Beam Dosimetry: A New Approach, Nanotechnologies In Russia, 15 (2020) 175–181. [3] A. Mosayebi, S. Malekie, A. Rahimi, F. Ziaie, Experimental study on polystyrene-MWCNT nanocomposite as a radiation dosimeter, Radiation Physics and Chemistry, 164 (2019) 108362. [4] F. Kazemi, S. Malekie, M.A. Hosseini, A Monte Carlo Study on the Shielding Properties of a Novel Polyvinyl Alcohol (PVA)/WO3 Composite, Against Gamma Rays, Using the MCNPX Code, Journal of Biomedical Physics Engineering, 9 (2019) 465. [5] A. Mosayebi, S. Malekie, F. Ziaie, A feasibility study of polystyrene/CNT nano-composite as a dosimeter for diagnostic and therapeutic purposes, Journal of Instrumentation, 12 (2017) P05012. [6] S. Malekie, F. Ziaie, A two-dimensional simulation to predict the electrical behavior of carbon nanotube/polymer composites, Journal of Polymer Engineering, 37 (2017) 205-210. [7] S. Malekie, N. Hajiloo, Comparative Study of Micro and Nano Size WO3/E44 Epoxy Composite as Gamma Radiation Shielding Using MCNP and Experiment, Chinese Physics Letter, 34 (2017) 108102. [8] S. Feizi, S. Malekie, R. Rahighi, A. Tayyebi, F. Ziaie, Evaluation of dosimetric characteristics of graphene oxide/PVC nanocomposite for gamma radiation applications, Radiochimica Acta, 105 (2017) 161-170. [9] S. Malekie, F. Ziaie, M.A. Naeini, Simulation of polycarbonate-CNT nanocomposite dosimeter based on electrical characteristics, Kerntechnik, 81 (2016) 647-650. [10] S. Malekie, F. Ziaie, S. Feizi, A. Esmaeli, Dosimetry characteristics of HDPE-SWCNT nanocomposite for real time application, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 833 (2016) 127-133. [11] S. Malekie, F. Ziaie, A. Esmaeli, Study on dosimetry characteristics of polymer–CNT nanocomposites: Effect of polymer matrix, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 816 (2016) 101-105. [12] S. Malekie, F. Ziaie, Study on a novel dosimeter based on polyethylene–carbon nanotube composite, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 791 (2015) 1-5. [13] A. Intaniwet, C.A. Mills, M. Shkunov, P.J. Sellin, J.L. Keddie, Heavy metallic oxide nanoparticles for enhanced sensitivity in semiconducting polymer x-ray detectors, Nanotechnology, 23 (2012) 235502. [14] O. Korostynska, K. Arshak, D. Morris, A. Arshak, E. Jafer, Radiation-induced changes in the electrical properties of carbon filled PVDF thick films, Materials Science and Engineering: B, 141 (2007) 115-120. [15] M.S. Saavedra, Novel Organic Based Nano-composite Detector Films: The Making and Testing of CNT Doped Poly(acrylate) Thin Films on Ceramic Chip Substrates, Department of Physics, University of Surrey, Guildford, Surrey, 2005, pp. 37. [16] H. Kang, S. Min, B. Seo, C. Roh, S. Hong, J.H. Cheong, Low energy beta emitter measurement: A review, Chemosensors, 8 (2020) 106. [17] F.H. Attix, Introduction to radiological physics and radiation dosimetry, WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim, Madison,Wisconsin, 2004. [18] T. Yanagida, Inorganic scintillating materials and scintillation detectors, Proceedings of the Japan Academy, Series B, 94 (2018) 75-97. [19] J. Borg, Dosimetry of low-energy beta radiation, Risoe National Lab., 1996. [20] L. Miramonti, A plastic scintillator detector for beta particles, Radiation Measurements, 35 (2002) 347-354. [21] M.F. L'annunziata, Radioactivity: introduction and history, from the quantum to quarks, Elsevier2016. [22] G.F. Knoll, Radiation Detection and Measurement, 4th ed., John Wiley & Sons, Inc, university of Michigan, USA, 2010. [23] L. Torrisi, Radiation damage in polyvinyltoluene (PVT) induced by 50–400 keV helium beams, Radiation Effects and Defects in Solids, 143 (1997) 19-31. [24] M. Ghergherehchi, H. Afarideh, M. Ghannadi, A. Mohammadzadeh, G.R. Aslani, B. Boghrati, Proton beam dosimetry: a comparison between a plastic scintillator, ionization chamber and Faraday cup, Journal of Radiation Research, 51 (2010) 423-430. [25] A. Quaranta, A. Vomiero, G. Della Mea, Scintillation mechanism and efficiency of ternary scintillator thin films, IEEE Transactions on Nuclear Science, 49 (2002) 2610-2615. [26] A.K. Tam, O. Boyraz, J. Unangst, P. Nazareta, M. Schreuder, M. Nilsson, Quantum-dot doped polymeric scintillation material for radiation detection, Radiation Measurements, 111 (2018) 27-34. [27] T. Osswald, J.P. Hernández-Ortiz, Polymer Processing, Modeling Simulation, Hanser Publishers, Munich, Germany2006. [28] M.F. L'Annunziata, Radiation physics and radionuclide decay, in: Handbook of Radioactivity Analysis, Elsevier, 2012, pp. 1-162. [29] https://physics.nist.gov/PhysRefData/Star/Text/ESTAR.html . [30] A.R. Vatankhah, M.A. Hosseini, S. Malekie, The characterization of gamma-irradiated carbon-nanostructured materials carried out using a multi-analytical approach including Raman spectroscopy, Applied Surface Science, 488 (2019) 671-680. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Major revision 09 Dec, 2021 Reviews received at journal 30 Nov, 2021 Reviewers agreed at journal 19 Nov, 2021 Reviewers invited by journal 18 Nov, 2021 Editor assigned by journal 18 Nov, 2021 Editor invited by journal 12 Nov, 2021 Submission checks completed at journal 12 Nov, 2021 First submitted to journal 02 Nov, 2021 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-1043040","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":63016330,"identity":"760fee0d-8106-4009-83b8-4bc10d92da7c","order_by":0,"name":"Seyed Musa Safdari","email":"","orcid":"","institution":"Islamic Azad University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Seyed","middleName":"Musa","lastName":"Safdari","suffix":""},{"id":63016331,"identity":"3b26ad08-4e26-4638-891f-c300bdb01d03","order_by":1,"name":"Shahryar Malekie","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA1UlEQVRIiWNgGAWjYHACxgMMByTkQKwDYD4zEXpAWoxJ1sKQ2EC0q+SnHX5w4MMZi/T+9uaDBxgq7tk1sPM+wKvF4HaawcEZNyRyZ5w5lnCA4UxxcgMzuwF+LdIJBod5PkjkNtzIMTjA2JaQzMDMRsBhs9M/HP7zQSJd/v4bIrUw3M4xOMxwQyLB4AYPWIsdQS0Gt3MKDvackTDceCYt4UDCmYQENiIctvHBj2N18nLHDx/+8KEiwZ6f/xgBh6GABAaGxDZSNICBPck6RsEoGAWjYNgDACqFSmqQrx66AAAAAElFTkSuQmCC","orcid":"","institution":"Nuclear Science and Technology Research Institute","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"Shahryar","middleName":"","lastName":"Malekie","suffix":""},{"id":63016332,"identity":"e17c150a-68da-4ab6-a783-1f71965e4dbe","order_by":2,"name":"Sedigheh Kashian","email":"","orcid":"","institution":"Nuclear Science and Technology Research Institute","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Sedigheh","middleName":"","lastName":"Kashian","suffix":""},{"id":63016333,"identity":"6bf83e52-ddb2-4422-80e4-1359fa2cf8a5","order_by":3,"name":"Morteza Akbari","email":"","orcid":"","institution":"Islamic Azad University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Morteza","middleName":"","lastName":"Akbari","suffix":""}],"badges":[],"createdAt":"2021-11-02 10:44:02","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-1043040/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-1043040/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":15593807,"identity":"cd57fbba-d312-4b2b-bf94-077e985451e0","added_by":"auto","created_at":"2021-11-16 15:14:21","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":62661,"visible":true,"origin":"","legend":"Set up the arrangement of electric current measurement of 50 wt% PC-Bi2O3 nanocomposite applying the 90Sr beta-emitter using an electrometer.","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-1043040/v1/317e037f2e98f3b14242f53f.jpg"},{"id":15593810,"identity":"1346e028-a829-466b-a1d6-20de8856a1ba","added_by":"auto","created_at":"2021-11-16 15:14:21","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":46568,"visible":true,"origin":"","legend":"Illustration of FESEM of the fractured surface corresponding to 50 wt% PC-Bi2O3 nanocomposite.","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-1043040/v1/6f0ea214791f9e544ab407b7.jpg"},{"id":15593808,"identity":"12662dfe-d68d-4e2b-97ba-07a86946c3ec","added_by":"auto","created_at":"2021-11-16 15:14:21","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":33899,"visible":true,"origin":"","legend":"Calculation of electrons range in different weight fractions of PC-Bi2O3 composite for electrons at energies of (A) 546.2 keV, and (B) 2.28 MeV using the ESTAR program.","description":"","filename":"3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-1043040/v1/c11e70c359f8150fb89ba457.jpg"},{"id":15593809,"identity":"aaac2567-d09c-413e-a5be-8ec3e0d84178","added_by":"auto","created_at":"2021-11-16 15:14:21","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":47497,"visible":true,"origin":"","legend":"The total stopping power of electrons at different energies up to 3 MeV for various weight percentages of PC-Bi2O3 composite using the ESTAR program.","description":"","filename":"4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-1043040/v1/7d1f56a922c32b6c7f5a9c29.jpg"},{"id":15594444,"identity":"f53e8585-c376-4688-8a47-d2ff33ce07c3","added_by":"auto","created_at":"2021-11-16 15:17:21","extension":"jpg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":41790,"visible":true,"origin":"","legend":"Detection response of 50 wt% PC-Bi2O3 nanocomposite to 90Sr beta-emitter source (A) for all SSDs, and (B) linear fit with a correlation coefficient of ~0.9933, exhibiting 1.5% standard deviation. ","description":"","filename":"5.jpg","url":"https://assets-eu.researchsquare.com/files/rs-1043040/v1/baa2c212bcabd5ce648af4f5.jpg"},{"id":15593813,"identity":"6b260b1e-1479-46f5-bea2-95c5473eec94","added_by":"auto","created_at":"2021-11-16 15:14:21","extension":"jpg","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":28069,"visible":true,"origin":"","legend":"Signal to noise ratio of 50 wt% PC-Bi2O3 nanocomposite for detection response to 90Sr beta-rays. ","description":"","filename":"6.jpg","url":"https://assets-eu.researchsquare.com/files/rs-1043040/v1/2fb8198debfe04f09e9f4d63.jpg"},{"id":15593811,"identity":"05008f6e-9782-4277-9f92-27ed6c77453b","added_by":"auto","created_at":"2021-11-16 15:14:21","extension":"jpg","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":28441,"visible":true,"origin":"","legend":"I-V plot of the 50 wt% sample irradiated by 90Sr at fixed SSD=30 cm and dose rate of 102.436 mSv/h, exhibiting an average standard deviation of 3.8%. ","description":"","filename":"7.jpg","url":"https://assets-eu.researchsquare.com/files/rs-1043040/v1/208872cd7aafa36de702c3ea.jpg"},{"id":15594445,"identity":"a7ca5302-fd8d-4585-94e8-eadf7d0e817b","added_by":"auto","created_at":"2021-11-16 15:17:24","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":440609,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-1043040/v1/09a1fa60-a48a-4de8-91a1-8b96b33deaee.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003eIntroducing a Novel Beta-ray Detector Based on Polycarbonate/ Bismuth Oxide Nanocomposite: Simulation and Experiment\u003c/p\u003e","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eDetection and dosimetry of ionizing radiation are of important issues in the nuclear industry. Recently, polymer-nanocomposites have been used as radiation sensors, detectors, dosimeters, and shielding materials [\u003ca href=\"#_ENREF_1\" title=\"Mehrara, 2021 #1502\"\u003e1-15\u003c/a\u003e].\u003c/p\u003e\n\u003cp\u003eThe mechanisms of interaction of beta particles with matter is categorized in two sections, electron excitation and ionization, in which electrons interact with the particles traversing the material via the Coulomb electric field [\u003ca href=\"#_ENREF_16\" title=\"Kang, 2020 #1580\"\u003e16-18\u003c/a\u003e]. Electrons lose their energy by friction attributed to the CSDA, or continuous slowing-down approximation [\u003ca href=\"#_ENREF_19\" title=\"Borg, 1996 #1581\"\u003e19-21\u003c/a\u003e]. The collisions of electrons with the particles are including hard collisions or inelastic scattering with orbital electrons produces excitation or ionization of electrons, and secondary electrons, inelastic scattering with nuclei leads to produce Bremsstrahlung, and soft collisions or elastic scattering, in which electrons lose a small fraction of their energies [\u003ca href=\"#_ENREF_16\" title=\"Kang, 2020 #1580\"\u003e16\u003c/a\u003e].\u003c/p\u003e\n\u003cp\u003eSome radioisotopes decay via beta-minus emission producing the fast electrons [\u003ca href=\"#_ENREF_22\" title=\"Knoll, 2010 #200\"\u003e22\u003c/a\u003e]. Several pure beta-emitters are \u003csup\u003e3\u003c/sup\u003eH (18.6 keV), \u003csup\u003e14\u003c/sup\u003eC (156 keV), \u003csup\u003e32\u003c/sup\u003eP (1.71 MeV),\u003csup\u003e\u0026nbsp;33\u003c/sup\u003eP (248 keV),\u003csup\u003e\u0026nbsp;35\u003c/sup\u003eS (167 keV), \u003csup\u003e36\u003c/sup\u003eCl (714 keV),\u003csup\u003e\u0026nbsp;345\u003c/sup\u003eCa (252 keV), \u003csup\u003e63\u003c/sup\u003eNi (67 keV), \u003csup\u003e90\u003c/sup\u003eSr/\u003csup\u003e90\u003c/sup\u003eY (546 keV/2.27 MeV), \u003csup\u003e147\u003c/sup\u003ePm (224 keV), and \u003csup\u003e204\u003c/sup\u003eTl (766 keV) [\u003ca href=\"#_ENREF_22\" title=\"Knoll, 2010 #200\"\u003e22\u003c/a\u003e].Various types of scintillators are commonly used to detect beta-rays. In addition, low Z materials including organic polymers are excellent absorbers of charged particles such as beta-rays, which will provide high sensitivity for charged particle detection\u0026nbsp;[\u003ca href=\"#_ENREF_20\" title=\"Miramonti, 2002 #1583\"\u003e20\u003c/a\u003e,\u0026nbsp;\u003ca href=\"#_ENREF_23\" title=\"Torrisi, 1997 #1533\"\u003e23-26\u003c/a\u003e]. A disadvantage of some scintillators and gas-flow type proportional counters is limitations due to their hygroscopicity, and scalability\u0026nbsp;[\u003ca href=\"#_ENREF_26\" title=\"Tam, 2018 #1537\"\u003e26\u003c/a\u003e].\u003c/p\u003e\n\u003cp\u003eThe main purpose of this research is to design and fabricate of a novel beta solid-state detector to measure the dose rate of beta-emitter sources in real-time. The material used is new in its kind and uses Polycarbonate/Bismuth oxide (PC-Bi\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e\u0026nbsp;\u003c/sub\u003ecomposite. The reason for choosing polycarbonate as a polymer matrix is that PC is essentially an amorphous polymer that is expected to have a more suitable bond with bismuth oxide nanoparticles, because the crystalline regions of the polymer often repel nanoparticles, so the nanoparticles are dispersed in amorphous regions. In general, a polymer is composed of two crystalline and amorphous phases in terms of molecular structure. In the crystalline phase, the crystals are arranged in regular polymer chains called lamellae with a length of 20-60 nm and a distance of 0.736 nm from each other\u0026nbsp;[\u003ca href=\"#_ENREF_27\" title=\"Osswald, 2006 #1417\"\u003e27\u003c/a\u003e]. Since in this research, Bi\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e fillers with the sizes of 90-210 nm are used, so the probability of Bi\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e nanoparticles entering the crystalline region of the polymer is very low and these particles tend to be placed in the amorphous part and the amount of polymer crystallinity increases through the nucleation process. Therefore, the possibility of increasing the crystallinity of polycarbonate is enhanced by adding Bi\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e nanoparticles to it. For the PC-Bi\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u0026nbsp;\u003c/sub\u003ecomposite\u003csub\u003e\u0026nbsp;\u003c/sub\u003edetector, the amount of sensitivity or minimum detectable dose rate (MDDR) for the detection of beta-rays can be controlled via heavy metal oxide inclusions into the polymer matrix. Generally, various factors affect the detector response, including polymer crystallinity, the weight percentage of metal oxide nanoparticles, nanocomposite thickness and other factors. Also, the homogeneous dispersion of metal oxide nanoparticles into the polymer matrix plays an important role in the detection response of this material.\u003c/p\u003e\n\u003cp\u003eThe selection of suitable thickness for a solid detector, considering the charge particle equilibrium (CPE) is a key factor\u0026nbsp;in the radiation ionizing detection. So, calculation of range and stopping power of electrons at different energies and weight fractions of the inclusions in the polymer composite using the ESTAR program should be carried out. After evaluation of the electron range in the media, it is possible to calculate the exact amount of optimal detector thickness at certain energies.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIn this research,\u0026nbsp;Strontium-90 (\u003csup\u003e90\u003c/sup\u003eSr) was chosen as a pure beta-emitter source. The \u003csup\u003e90\u003c/sup\u003eSr source is generated in the reactor by the fission reaction of the \u003csup\u003e235\u003c/sup\u003eU nuclei as\u0026nbsp;[\u003ca href=\"#_ENREF_28\" title=\"L'Annunziata, 2012 #1468\"\u003e28\u003c/a\u003e]:\u003c/p\u003e\n\u003cp\u003e\u003cimg src=\"https://myfiles.space/user_files/69515_16346c490bab499e/69515_custom_files/img1637050130.png\"\u003e\u003c/p\u003e\n\u003cp\u003eThe decay mechanism of \u003csup\u003e90\u003c/sup\u003eSr is as follows\u0026nbsp;[\u003ca href=\"#_ENREF_28\" title=\"L'Annunziata, 2012 #1468\"\u003e28\u003c/a\u003e]:\u003c/p\u003e\n\u003cp\u003e\u003cimg src=\"https://myfiles.space/user_files/69515_16346c490bab499e/69515_custom_files/img1637050155.png\"\u003e\u003c/p\u003e\n\u003cp\u003eIn which,\u0026nbsp;\u003csup\u003e90\u003c/sup\u003eSr decays to \u003csup\u003e90\u003c/sup\u003eY with a half-life of 28.78 years, with beta particle energy of 546.2 keV; the \u003csup\u003e90\u003c/sup\u003eY, which emits beta and gamma, converts to \u003csup\u003e90\u003c/sup\u003eZr with a half-life of 64 hours, with beta particle energy of 2.28 MeV\u0026nbsp;[\u003ca href=\"#_ENREF_28\" title=\"L'Annunziata, 2012 #1468\"\u003e28\u003c/a\u003e].\u003c/p\u003e\n\u003cp\u003eIn\u0026nbsp;this research, for the first time, a novel beta-ray detector based on PC-Bi\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e nanocomposite was introduced, and the detection response of this material was investigated theoretically and experimentally to a pure beta particle source of \u003csup\u003e90\u003c/sup\u003eSr.\u003c/p\u003e"},{"header":"2. Materials And Methods","content":"\u003cp\u003e2.1 Sample preparation\u003c/p\u003e\n\u003cp\u003eThe PC-Bi2O3 nanocomposite at a concentration of 50 wt% was synthesized using the solution casting method. The details of the synthesis have been described in our previous work [\u003ca href=\"#_ENREF_1\" title=\"Mehrara, 2021 #1502\"\u003e1\u003c/a\u003e]. The densities of PC matrix and Bi\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e filler particles were 1.2 g/cm\u003csup\u003e3\u003c/sup\u003e and 8.9 g/cm\u003csup\u003e3\u0026nbsp;\u003c/sup\u003erespectively. The average size of Bi\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u0026nbsp;\u003c/sub\u003eparticles in the prepared material was 90-210 nm. In this experimental work, to irradiate PC-Bi\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e nanocomposite with beta-rays, a beta irradiation system model Buchler BSS-BA containing \u003csup\u003e90\u003c/sup\u003eSr reference source with an initial activity of 50 mCi (production date 1978) located in Secondary Standard Dosimetry Laboratory (SSDL) Karaj-Iran was used at different source-surface distances (SSDs) according to Table 1. Also, as exhibited in Fig. 1, the Supermax Standard Imaging electrometer was used to measure the electric charge during irradiation at fixed time steps of 15 Seconds. Also, to fabricate the electrodes on two surfaces of the top and bottom of the nanocomposite, copper sheets with dimensions of 3.5 cm\u0026times;3.5 cm, and 4 cm\u0026times;4 cm with a thickness of 100 \u0026micro;m adhered to the top and bottom surfaces of the 50 wt% PC-Bi\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e nanocomposite respectively using the silver paste.\u003c/p\u003e\n\u003cp\u003eTable 1. The amounts of SSDs for \u003csup\u003e90\u003c/sup\u003eSr and corresponding dose rates\u003c/p\u003e\n\u003cdiv\u003e\n \u003ctable border=\"1\" cellpadding=\"0\" cellspacing=\"0\" width=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" width=\"40.692640692640694%\"\u003e\n \u003cp\u003e\u003cstrong\u003eSSD (cm)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" width=\"59.307359307359306%\"\u003e\n \u003cp\u003e\u003cstrong\u003eDose Rate (mSv/h)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" width=\"40.692640692640694%\"\u003e\n \u003cp\u003e30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" width=\"59.307359307359306%\"\u003e\n \u003cp\u003e102.436\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" width=\"40.692640692640694%\"\u003e\n \u003cp\u003e35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" width=\"59.307359307359306%\"\u003e\n \u003cp\u003e75.259\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" width=\"40.692640692640694%\"\u003e\n \u003cp\u003e40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" width=\"59.307359307359306%\"\u003e\n \u003cp\u003e57.620\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" width=\"40.692640692640694%\"\u003e\n \u003cp\u003e45\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" width=\"59.307359307359306%\"\u003e\n \u003cp\u003e45.527\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" width=\"40.692640692640694%\"\u003e\n \u003cp\u003e50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" width=\"59.307359307359306%\"\u003e\n \u003cp\u003e36.877\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" width=\"40.692640692640694%\"\u003e\n \u003cp\u003e55\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" width=\"59.307359307359306%\"\u003e\n \u003cp\u003e30.477\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003e2.2 Simulation methodology\u003c/p\u003e\n\u003cp\u003eIn this research, a pure beta-emitter of \u003csup\u003e90\u003c/sup\u003eSr with two energies at 546.2 keV, and 2.28 MeV was chosen for the measurements. To calculate the two key factors namely range and stopping power of the produced electrons in the composite via beta irradiation at different weight fractions of the heavy metal oxide fillers, the ESTAR program was applied [\u003ca href=\"#_ENREF_29\" title=\", #1531\"\u003e29\u003c/a\u003e].\u003c/p\u003e\n\u003cp\u003eThe performance of any ionizing radiation detector essentially depends on the approach in which the radiation to be detected interacts with the material of the detector itself\u0026nbsp;[\u003ca href=\"#_ENREF_22\" title=\"Knoll, 2010 #200\"\u003e22\u003c/a\u003e]. The linear stopping power for charged particles in a particular absorber is defined as the energy loss for that particle within the material divided by the corresponding path length via the Bethe-Bloch formula\u0026nbsp;[\u003ca href=\"#_ENREF_22\" title=\"Knoll, 2010 #200\"\u003e22\u003c/a\u003e]:\u003c/p\u003e\n\u003cp\u003e\u003cimg src=\"https://myfiles.space/user_files/69515_16346c490bab499e/69515_custom_files/img1637050232.png\"\u003e\u003c/p\u003e\n\u003cp\u003eIn which v, ze are the velocity and charge of the particles, N and Z are the number density and atomic number of the absorber atoms, m\u003csub\u003e0\u003c/sub\u003e is the electron rest mass, and e is the electronic charge, also I indicates to average excitation and ionization potential of the absorber material [\u003ca href=\"#_ENREF_22\" title=\"Knoll, 2010 #200\"\u003e22\u003c/a\u003e].\u003c/p\u003e"},{"header":"3. Results And Discussion","content":"\u003cp\u003e3.1 FESEM analysis\u003c/p\u003e\n\u003cp\u003eFig. 2 depicts the Field Emission Scanning Electron Microscopy (FESEM) image of the prepared 50 wt% PC-Bi\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e nanocomposite. For this purpose, the FESEM device model MIRA3TESCAN-XMU was used. As can be observed in Fig. 2, a cross-sectional view of the sample showed a suitable dispersion of Bi\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u0026nbsp;\u003c/sub\u003enanoparticles into the PC matrix. FESEM analysis approved the presence of the Bi\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e nanoparticles in the polymer-nanocomposite.\u003c/p\u003e\n\u003cp\u003e3.2 Results of simulation\u003c/p\u003e\n\u003cp\u003eAs can be seen from Fig. 3 (A, B), simulation results of the beta-emitter source of \u003csup\u003e90\u003c/sup\u003eSr at two energies of 546.2 keV and 2.28 MeV for 50 wt% PC-Bi\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e composite at various weight fractions are depicted. It can be mentioned that increasing the weight fraction of the bismuth oxide particles into the polycarbonate matrix, led to a linear decrease of the range of beta particles in the composite material. This phenomenon is probably due to the increasing probability of occurring Bremsstrahlung secondary radiation by adding the Bi\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e wt% in the polymer matrix. The energy dissipation of incident beta particles via interaction with this composite material is increased by Bremsstrahlung radiation and therefore the range of the particles will be decreased subsequently.\u003c/p\u003e\n\u003cp\u003eAlso, according to Fig. 4, the total stopping power of electrons at various energies up to 3 MeV for\u0026nbsp;PC-Bi\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e composite at different weight fractions was calculated using the ESTAR program. It can be deduced that at the specific and constant energy, with increasing the weight percentage of bismuth oxide particles in the polycarbonate matrix, the amount of stopping power of electrons in the composite will be increased. This phenomenon could be attributed to the increment of the effective atomic number of the composite in higher amounts of the reinforcement phase regarding the Bethe-Bloch formula. Results of simulation showed that the optimal thickness for detection of predominant beta particles of 546.2 keV in \u003csup\u003e90\u003c/sup\u003eSr source for 50 wt% PC-Bi\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e composite was estimated to be approximately 1.2 mm. It seems that a thickness of 1 mm for this detector would be suitable for measuring beta-rays with the energy of 546 keV, and also it can be mentioned that the CPE phenomenon would be established. However, detecting the higher energy electrons including 2.28 MeV will contribute to relatively poor efficiency. To improve the efficiency of the detector, it is possible to increase the thickness of the material, nevertheless, at higher thicknesses, the applied electric field will be decreased and it will practically lose its uniformity which leads to reduced sensitivity of the detector. Thus, selecting the optimal thickness for this detector is essential.\u003c/p\u003e\n\u003cp id=\"isPasted\"\u003eAs can be seen from Fig. 5, for 50 wt% PC-Bi\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e nanocomposite, the values of photocurrent at a fixed voltage of 400 V was increased gradually from 30-75 mSv/h and finally tend to saturate afterwards at 102 mSv/h. It seems this saturation is related to the recombination of beta induced-charged particles, in which, the detection response should be measured at higher voltages.\u003c/p\u003e\n\u003cp\u003eOne of the most important quantities in determining the sensitivity of a detector is the signal to noise ratio. This ratio is obtained by dividing the photocurrent by the amount of dark current. The dark current and photocurrent values in the measurement phase were in the order of pA, and nA\u003cstrong\u003e\u003cspan dir=\"RTL\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/strong\u003erespectively.\u0026nbsp;In Fig. 6, signal to noise ratio of the 50 wt% PC-Bi\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e nanocomposite for detection response to \u003csup\u003e90\u003c/sup\u003eSr beta-rays is exhibited. As can be seen from Fig. 6, with increasing the amount of dose rate ranging from 30-102 mSv/h, the signal to noise ratio will be improved subsequently. This phenomenon might be pertinent to atomic displacements in the nanocomposite considering the interaction of beta particles with the atomic structures of this material. It is worth pointing out here that ionizing radiations including electrons through the interaction with the nanostructured materials, due to atomic displacement can alter the crystal structure and induce various events such as emission of secondary electrons, excitation, ionization, and bond breakage of the material atomic structures [\u003ca href=\"#_ENREF_30\" title=\"Vatankhah, 2019 #1273\"\u003e30\u003c/a\u003e].\u003c/p\u003e\n\u003cp\u003eGenerally, finding the suitable operating or working voltage plays an important role in radiation detectors. In Fig. 7, the I-V plot of the detector based on 50 wt% PC-Bi\u003csub id=\"isPasted\"\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e nanocomposite in the presence of beta radiation field of \u003csup\u003e90\u003c/sup\u003eSr source is exhibited, in which I is photocurrent in terms of nA which is measured by the electrometer. It is obvious from Fig. 7 that the detector response (photocurrent) is linear at various voltages range from 100 V to 1000 V. This linearity means that there is no saturation in the detector response of this nanocomposite in the aforementioned voltage range. So it is possible to choose a suitable operating voltage to achieve a significant sensitivity to detect the beta-rays efficiently.\u003c/p\u003e"},{"header":"4. Conclusion","content":"\u003cp\u003eIn this\u0026nbsp;research, for the first time, the detection response of a novel beta-ray detector based on Polycarbonate/Bismuth Oxide composite was studied via the simulation and experiment. Firstly, at the simulation phase, the range and stopping power of electrons related to \u003csup\u003e90\u003c/sup\u003eSr beta-emitter were calculated for various weight fractions of PC-Bi\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e composites up to 50 wt% using the ESTAR program. Results of simulation showed that the amount of heavy metal oxide inclusions in the polymer composite had a substantial influence on the range and stopping power quantities of electrons in the composite detector. So that, increasing the weight fraction of bismuth oxide particles in the polycarbonate matrix, led to a decrease in the range of beta particles, and increase the amount of stopping power of the composite detector linearly. So,\u0026nbsp;the optimal thickness for detection of predominant beta particles of 546.2 keV in \u003csup\u003e90\u003c/sup\u003eSr source for 50 wt% composite was estimated to be approximately 1.2 mm.\u003c/p\u003e\n\u003cp\u003eAt the experimental phase, the 50 wt%\u0026nbsp;PC-Bi\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e nanocomposite was irradiated by a beta-emitter of \u003csup\u003e90\u003c/sup\u003eSr source and the amount of electric current passing through the nanocomposite was measured using an electrometer at various voltages of 100-1000 V. besides, I-V plots exhibited a linear response at various voltages. Also, the measured dose rate was linear with a linear correlation coefficient of ~0.9933 ranging from 30-75 mSv/h.\u003c/p\u003e\n\u003cp\u003eResults of this exploration showed that the cost-benefit Polycarbonate/Bismuth Oxide nanocomposite can be considered as a novel real-time beta detector to be used in radioactive monitoring systems for medical and industrial applications.\u0026nbsp;\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was extracted as part of a Master\u0026apos;s thesis by Mr S. M. Safdari, MSc student at Islamic Azad University, Science and Research Branch, Tehran. We appreciate those who supported us in handling this research, especially the staff of NSTRI which resulted in the success of this study. Moreover, we would like to appreciate the efforts of Ms R. Mehrara and Professor S. M. Saleh Kotahi at the Physics Department, K. N. Toosi University of Technology for preparing the nanocomposite.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eContributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eS.M. and S.K. prepared the nanocomposite and developed the idea, S.M.S did the measurement and all authors contributed manuscript writing.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of Interest\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no conflict of interest.\u003c/p\u003e"},{"header":"References","content":"\u003cp\u003e[1] R. Mehrara, S. Malekie, S.M. Saleh Kotahi, S. Kashian, Introducing a novel low energy gamma ray shield utilizing Polycarbonate Bismuth Oxide composite, Scientific Reports, 11 (2021) 10614.\u003c/p\u003e\n\u003cp\u003e[2] A. Rahimi, F. Ziaie, N. Sheikh, S. Malekie, Calorimetry System Based on Polystyrene/MWCNT Nanocomposite for Electron Beam Dosimetry: A New Approach, Nanotechnologies In Russia, 15 (2020) 175\u0026ndash;181.\u003c/p\u003e\n\u003cp\u003e[3] A. Mosayebi, S. Malekie, A. Rahimi, F. Ziaie, Experimental study on polystyrene-MWCNT nanocomposite as a radiation dosimeter, Radiation Physics and Chemistry, 164 (2019) 108362.\u003c/p\u003e\n\u003cp\u003e[4] F. Kazemi, S. Malekie, M.A. Hosseini, A Monte Carlo Study on the Shielding Properties of a Novel Polyvinyl Alcohol (PVA)/WO3 Composite, Against Gamma Rays, Using the MCNPX Code, Journal of Biomedical Physics Engineering, 9 (2019) 465.\u003c/p\u003e\n\u003cp\u003e[5] A. Mosayebi, S. Malekie, F. Ziaie, A feasibility study of polystyrene/CNT nano-composite as a dosimeter for diagnostic and therapeutic purposes, Journal of Instrumentation, 12 (2017) P05012.\u003c/p\u003e\n\u003cp\u003e[6] S. Malekie, F. Ziaie, A two-dimensional simulation to predict the electrical behavior of carbon nanotube/polymer composites, Journal of Polymer Engineering, 37 (2017) 205-210.\u003c/p\u003e\n\u003cp\u003e[7] S. Malekie, N. Hajiloo, Comparative Study of Micro and Nano Size WO3/E44 Epoxy Composite as Gamma Radiation Shielding Using MCNP and Experiment, Chinese Physics Letter, 34 (2017) 108102.\u003c/p\u003e\n\u003cp\u003e[8] S. Feizi, S. Malekie, R. Rahighi, A. Tayyebi, F. Ziaie, Evaluation of dosimetric characteristics of graphene oxide/PVC nanocomposite for gamma radiation applications, Radiochimica Acta, 105 (2017) 161-170.\u003c/p\u003e\n\u003cp\u003e[9] S. Malekie, F. Ziaie, M.A. Naeini, Simulation of polycarbonate-CNT nanocomposite dosimeter based on electrical characteristics, Kerntechnik, 81 (2016) 647-650.\u003c/p\u003e\n\u003cp\u003e[10] S. Malekie, F. Ziaie, S. Feizi, A. Esmaeli, Dosimetry characteristics of HDPE-SWCNT nanocomposite for real time application, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 833 (2016) 127-133.\u003c/p\u003e\n\u003cp\u003e[11] S. Malekie, F. Ziaie, A. Esmaeli, Study on dosimetry characteristics of polymer\u0026ndash;CNT nanocomposites: Effect of polymer matrix, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 816 (2016) 101-105.\u003c/p\u003e\n\u003cp\u003e[12] S. Malekie, F. Ziaie, Study on a novel dosimeter based on polyethylene\u0026ndash;carbon nanotube composite, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 791 (2015) 1-5.\u003c/p\u003e\n\u003cp\u003e[13] A. Intaniwet, C.A. Mills, M. Shkunov, P.J. Sellin, J.L. Keddie, Heavy metallic oxide nanoparticles for enhanced sensitivity in semiconducting polymer x-ray detectors, Nanotechnology, 23 (2012) 235502.\u003c/p\u003e\n\u003cp\u003e[14] O. Korostynska, K. Arshak, D. Morris, A. Arshak, E. Jafer, Radiation-induced changes in the electrical properties of carbon filled PVDF thick films, Materials Science and Engineering: B, 141 (2007) 115-120.\u003c/p\u003e\n\u003cp\u003e[15] M.S. Saavedra, Novel Organic Based Nano-composite Detector Films: The Making and Testing of CNT Doped Poly(acrylate) Thin Films on Ceramic Chip Substrates, \u0026nbsp;Department of Physics, University of Surrey, Guildford, Surrey, 2005, pp. 37.\u003c/p\u003e\n\u003cp\u003e[16] H. Kang, S. Min, B. Seo, C. Roh, S. Hong, J.H. Cheong, Low energy beta emitter measurement: A review, Chemosensors, 8 (2020) 106.\u003c/p\u003e\n\u003cp\u003e[17] F.H. Attix, Introduction to radiological physics and radiation dosimetry, WILEY-VCH Verlag GmbH \u0026amp; Co. KGaA, Weinheim, Madison,Wisconsin, 2004.\u003c/p\u003e\n\u003cp\u003e[18] T. Yanagida, Inorganic scintillating materials and scintillation detectors, Proceedings of the Japan Academy, Series B, 94 (2018) 75-97.\u003c/p\u003e\n\u003cp\u003e[19] J. Borg, Dosimetry of low-energy beta radiation, Risoe National Lab., 1996.\u003c/p\u003e\n\u003cp\u003e[20] L. Miramonti, A plastic scintillator detector for beta particles, Radiation Measurements, 35 (2002) 347-354.\u003c/p\u003e\n\u003cp\u003e[21] M.F. L\u0026apos;annunziata, Radioactivity: introduction and history, from the quantum to quarks, Elsevier2016.\u003c/p\u003e\n\u003cp\u003e[22] G.F. Knoll, Radiation Detection and Measurement, 4th ed., John Wiley \u0026amp; Sons, Inc, university of Michigan, USA, 2010.\u003c/p\u003e\n\u003cp\u003e[23] L. Torrisi, Radiation damage in polyvinyltoluene (PVT) induced by 50\u0026ndash;400 keV helium beams, Radiation Effects and Defects in Solids, 143 (1997) 19-31.\u003c/p\u003e\n\u003cp\u003e[24] M. Ghergherehchi, H. Afarideh, M. Ghannadi, A. Mohammadzadeh, G.R. Aslani, B. Boghrati, Proton beam dosimetry: a comparison between a plastic scintillator, ionization chamber and Faraday cup, Journal of Radiation Research, 51 (2010) 423-430.\u003c/p\u003e\n\u003cp\u003e[25] A. Quaranta, A. Vomiero, G. Della Mea, Scintillation mechanism and efficiency of ternary scintillator thin films, IEEE Transactions on Nuclear Science, 49 (2002) 2610-2615.\u003c/p\u003e\n\u003cp\u003e[26] A.K. Tam, O. Boyraz, J. Unangst, P. Nazareta, M. Schreuder, M. Nilsson, Quantum-dot doped polymeric scintillation material for radiation detection, Radiation Measurements, 111 (2018) 27-34.\u003c/p\u003e\n\u003cp\u003e[27] T. Osswald, J.P. Hern\u0026aacute;ndez-Ortiz, Polymer Processing, Modeling Simulation, Hanser Publishers, Munich, Germany2006.\u003c/p\u003e\n\u003cp\u003e[28] M.F. L\u0026apos;Annunziata, Radiation physics and radionuclide decay, in: \u0026nbsp;Handbook of Radioactivity Analysis, Elsevier, 2012, pp. 1-162.\u003c/p\u003e\n\u003cp\u003e[29] \u003ca href=\"https://physics.nist.gov/PhysRefData/Star/Text/ESTAR.html\"\u003ehttps://physics.nist.gov/PhysRefData/Star/Text/ESTAR.html\u003c/a\u003e.\u003c/p\u003e\n\u003cp\u003e[30] A.R. Vatankhah, M.A. Hosseini, S. Malekie, The characterization of gamma-irradiated carbon-nanostructured materials carried out using a multi-analytical approach including Raman spectroscopy, Applied Surface Science, 488 (2019) 671-680.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Beta Detector, PC-Bi2O3 nanocomposite, Dose Rate, Strontium-90, ESTAR Program","lastPublishedDoi":"10.21203/rs.3.rs-1043040/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-1043040/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eIn this research, for the first time, the detection response of Polycarbonate/Bismuth oxide composite to a pure beta-emitter \u003csup\u003e90\u003c/sup\u003eSr with two energies of 546.2 keV, and 2.28 MeV is studied. Firstly, the range and stopping power of the electrons of \u003csup\u003e90\u003c/sup\u003eSr in the composite at various concentrations of 0, 10, 20, 30, 40 and 50 wt% were calculated using the ESTAR program. Results of simulation demonstrated that the concentration of the heavy metal oxide particles into the polymer matrix played an important role to evaluate the range and stopping power of the electrons in the composite. Secondly, at the experimental phase, the sample of 50 wt% composite with dimensions of 4 cm\u0026times;4 cm\u0026times;0.1 cm\u003csup\u003e3\u003c/sup\u003e was prepared. Afterwards, the sample was irradiated by \u003csup\u003e90\u003c/sup\u003eSr and the amount of electric current was measured using an electrometer at voltages of 100-1000 V. Additionally, the I-V plot exhibited a linear response at different voltages in the fixed source surface distance. Results of this study showed that this composite can serve as a novel beta detector.\u003c/p\u003e","manuscriptTitle":"Introducing a Novel Beta-ray Detector Based on Polycarbonate/ Bismuth Oxide Nanocomposite: Simulation and Experiment","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2021-11-16 15:14:19","doi":"10.21203/rs.3.rs-1043040/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Major revision","date":"2021-12-09T05:58:05+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2021-11-30T11:39:09+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"4eea4050-38a9-4ac3-b7ef-0eb795a13365","date":"2021-11-19T06:16:14+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2021-11-18T14:59:51+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2021-11-18T14:58:53+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2021-11-12T11:15:00+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2021-11-12T11:12:22+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2021-11-02T10:29:52+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"1f2857f5-2ba5-4815-9e66-e48fc1cd2971","owner":[],"postedDate":"November 16th, 2021","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[{"id":8539957,"name":"Nuclear Medicine \u0026 Medical Imaging"}],"tags":[],"updatedAt":"2022-02-02T05:59:05+00:00","versionOfRecord":[],"versionCreatedAt":"2021-11-16 15:14:19","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-1043040","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-1043040","identity":"rs-1043040","version":["v1"]},"buildId":"cBFmMYwuxLRRLfASyISRj","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}