مقایسه تجربی پاسخ آشکارسازی و دزیمتری میکرو/ نانو کامپوزیت پلی وینیل الکل- اکسید تنگستن به پرتوهای گاما و نوترون

نویسندگان

1 سازمان انرژی اتمی ایران

2 دانشگاه آزاد اسلامی واحد ارسنجان

3 دانشگاه علوم پزشکی شیراز

10.22052/6.2.9

چکیده

اخیراً نانوکامپوزیت­های پلیمری به ­منظور آشکارسازی و دزیمتری پرتوهای گاما مورد استفاده قرار گرفته ­اند، اما به ­علت دارا بودن سطح مقطع جذب فوتونی پایین، حساسیت­ پذیری کمی نسبت به پرتوهای گاما نشان می­ دهند. به ­منظور غلبه بر این مشکل، ذرات اکسید فلزی با عدد اتمی بالا به ماتریس پلیمری افزوده می­گردند. بدین منظور در این کار تجربی ذرات اکسید تنگستن (WO3) به دو شکل نانو و میکرو در ماتریس پلی‌وینیل­ الکل (PVA) با درصد وزنی wt% 20 پخش شدند. در ساخت کامپوزیت (wt% 20)WO3-PVA  از روش محلولی بهره­گیری شد. آزمون FESEM به ­منظور بررسی ریخت­شناسی کامپوزیت مذکور صورت گرفت که بر پخش نانو/میکرو ذرات اکسید تنگستن در بستر پلیمری صحه‌گذاری نمود. بازده کوانتومی تضعیف فوتون­های گاما مربوط به چشمه 60Co برای کامپوزیت مذکور با استفاده از کد MCNP < /span> محاسبه شد که همخوانی قابل قبولی با نتایج XCOM نشان داد. از جمله عوامل مؤثر در پاسخ آشکارسازی و دزیمتری این دسته کامپوزیت­ها، تغییر جریان الکتریکی کامپوزیت در اثر جذب پرتو است. جریان تاریک و جریان تابشی نانو/میکرو کامپوزیت اکسید تنگستن-پلی­ وینیل­ الکل تحت پرتودهی گاما و نوترون به ترتیب مربوط به چشمه­ های 60Co و 241Am-Be توسط الکترومتر به روش دو پروبی در ولتاژهای 100 و 400 ولت اندازه‌گیری شد. نتایج اندازه­ گیری نشان داد که حساسیت­ پذیری نانوکامپوزیت نسبت به پرتوهای گاما بهتر از میکروکامپوزیت مذکور است. همچنین نسبت علامت به نوفه برای نمونه نانوکامپوزیت تحت پرتودهی گاما در محدوده آهنگ دز mGy/min 138-90 به­صورت خطی از 5 تا 40 افزایش یافت در حالی که کامپوزیت مذکور پاسخ قابل ملاحظه ­ای به پرتوهای نوترون نشان نداد.

کلیدواژه‌ها

عنوان مقاله [English]

Experimental comparison of dosimetry and detection response of micro/ nano WO3-PVA composite to gamma and neutron beams

نویسندگان [English]

  • Shahryar Malekie 1
  • Seyed Mehdi Hashemi Dizaji 1
  • Farhood Ziaie 1
  • Farideh Kazemi 2
  • Seyed Mohammad Hosseini 3
1
2
3
چکیده [English]

Recently, polymeric nanocomposites have been used in dosimetry and detection of gamma rays, but due to their low photon absorption cross section, they exhibit a small sensitivity to gamma rays. In order to overcome this problem, metal oxide particles with a high atomic number are added to the polymer matrix. For this purpose, in this work, tungsten oxide particles (WO3) were distributed in polyvinyl alcohol (PVA) matrix via two scales of nano and micro sizes of the fillers with a weight percentage of 20 wt%. A solvent solution was used in fabricating WO3-PVA composite (20 wt%). The FESEM test was performed to verify the composite rheology and to confirm the distribution of tungsten oxide micro/nanoparticles in the polymeric matrix. The quantum efficiency of gamma rays for 60Co was calculated for the aforementioned composite using the MCNP code, which showed an acceptable agreement with the XCOM results. One of the effective factors in detection response and dosimetry of this composite group is the change in the electrical current of the composite due to beam absorption. The dark current and photocurrent of tungsten oxide-polyvinyl alcohol nano/micro composite were measured in gamma and neutron radiation fields respectively by 60Co and 241Am-Be sources using two-probe electrometer in 100 V and 400 V voltages. The results showed that the sensitivity of nanocomposite to gamma rays is better than microcomposite. Also, the signal-to-noise ratio of nanocomposite for gamma-ray in the dose rate of 90-138 mGy/min increased linearly from 5 to 40, while the composite did not show a remarkable response to neutron beams.
 

کلیدواژه‌ها [English]

  • polyvinyl alcohol
  • Tungsten Oxide
  • Micro
  • Nano
  • Dosimetry and Detection

مراجع

[1] O. Korostynska, K. Arshak, D. Morris, A. Arshak and E. Jafer. Radiation-induced changes in the electrical properties of carbon filled PVDF thick films. Materials Science and Engineering: B, 141 (2007) 115–120. [2] F. Salimi-Ahmadabad, S. Malekie and F. Ziaie. The investigation of reinforcement phase distribution on electrical conductivity of Polymer-Carbon nanotube composite as radiation dosimeter: A Monte Carlo Method. Iranian Journal of Radiation Safety and Measurement, 4 (2016) 49–55. [3] S. Feizi, S. Malekie, R. Rahighi, A. Tayyebi and F. Ziaie. Evaluation of dosimetric characteristics of graphene oxide/PVC nanocomposite for gamma radiation applications. ract, 105 (2017) 161–170. [4] S. Malekie and N. Hajiloo. Comparative Study of Micro and Nano Size WO3/E44 Epoxy Composite as Gamma Radiation Shielding Using MCNP and Experiment. Chinese Physics Letters, 34 (2017) 108102. [5] T. Özdemir, A. Güngör and İ. Reyhancan. Flexible neutron shielding composite material of EPDM rubber with boron trioxide: Mechanical, thermal investigations and neutron shielding tests. Radiation Physics and Chemistry, 131 (2017) 7–12. [6] A. Mosayebi, S. Malekie and F. Ziaie .A feasibility study of polystyrene/CNT nano-composite as a dosimeter for diagnostic and therapeutic purposes. Journal of Instrumentation, 12 (2017) P05012. [7] C. Tan, R. James, B. Dong, M.S. Driver, J.A. Kelber, G. Downing and L.R. Cao. Characterization of a boron carbide-based polymer neutron sensor. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 803 (2015) 82–88. [8] S. Kyatsandra and R. Wilkins. Total Ionizing Dose X-ray Radiation Effects on MWCNT/PMMA Thin Film Composites. Nanotechnology, IEEE Transactions on, 14 (2015) 152–158. [9] A. Intaniwet, C.A. Mills, M. Shkunov, P.J. Sellin and J.L. Keddie. Heavy metallic oxide nanoparticles for enhanced sensitivity in semiconducting polymer x-ray detectors. Nanotechnology, 23 (2012) 235502. [10] J. Lobez and TimothyM. Swager. Radiation Detection:Resistivity Responses in Functional Poly(Olefin Sulfone)/Carbon Nanotube Composites. Angewandte Chemie International Edition, 49.1 (2010) 95–98. [11] F.A. Boroumand, M. Zhu, A.B. Dalton, J.L. Keddie and P.J. Sellin. Direct x-ray detection with conjugated polymer devices. Applied Physics Letters, 91 (2007). [12] 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) 37. [13] L. Ran, G. Yizhuo, W. Yidong, Y. Zhongjia, L. Min and Z. Zuoguang. Effect of particle size on gamma radiation shielding property of gadolinium oxide dispersed epoxy resin matrix composite. Materials Research Express, 4 (2017) 035035. [14] S. Malekie, F. Ziaie, S. Feizi and 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. [15] S. Malekie and F. Ziaie. A two-dimensional simulation to predict the electrical behavior of carbon nanotube/polymer composites. Journal of Polymer Engineering, 37(2016) 205–210. [16] S. Malekie, F. Ziaie and 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. [17] S. Malekie and 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. [18] F. Ziaie and S. Malekie. Study of electrical properties of a novel dosimeter based on polymer-carbon nanotube nano-composite. Iranian Journal of Radiation Safety and Measurement, 2 (2014) 17–20. [19] P. Beckerle and H. Ströbele. Charged particle detection in organic semiconductors. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 449 (2000) 302–31. [20] D. Natali and M. Sampietro. Detectors based on organic materials: status and perspectives. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 512 (2003) 419–426. [21] N. Hong. An Exploration of Neutron Detection in Semiconducting Boron Carbide. Theses, Dissertations, and Student Research: Department of Physics and Astronomy, University of Nebraska - Lincoln, (2012). [22] C. Kimblin, Contributors, K. Miller, B. Vogel, B. Quam, H. McHugh, G. Anthony, S. Jones and M. Grover. STL-20 : Conducting Polymers for Neutron Detection Principal Investigator. DOE/NV/25946--330. [23] M.J. Berger, J.H. Hubbell, S.M. Seltzer, J. Chang, J.S. Coursey, R. Sukumar, D.S. Zucker and K. Olsen, “XCOM Photon Cross Sections Database,” (1998). [25] Y. Wang, J. Wu and F. Wei. A treatment method to give separated multi-walled carbon nanotubes with high purity, high crystallization and a large aspect ratio. Carbon, 41 (2003) 2939–2948. [26] S. Nambiar and J.T. Yeow. Polymer-composite materials for radiation protection, ACS applied materials & interfaces, 4 (2012) 5717–5726.

فایل ها

هم رسانی

ارجاع به این مقاله

آمار