• Title/Summary/Keyword: shielding material

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A Study on the Shielding Element Using Monte Carlo Simulation (몬테카를로 시뮬레이션을 이용한 차폐체 원소 평가)

  • Kim, Ki-Jeong;Shim, Jae-Goo
    • Journal of radiological science and technology
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    • v.40 no.2
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    • pp.269-274
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    • 2017
  • In this research, we simulated the elementary star shielding ability using Monte Carlo simulation to apply medical radiation shielding sheet which can replace existing lead. In the selection of elements, mainly elements and metal elements having a large atomic number, which are known to have high shielding performance, recently, various composite materials have improved shielding performance, so that weight reduction, processability, In consideration of activity etc., 21 elements were selected. The simulation tools were utilized Monte Carlo method. As a result of simulating the shielding performance by each element, it was estimated that the shielding ratio is the highest at 98.82% and 98.44% for tungsten and gold.

Preparation of EMI Shielding Sheet by PVD Method and Its Characteristic of EMI Shielding Efficiency (PVD법을 이용한 전자파 차폐용 시트 제조 및 차폐효율 특성)

  • Chae, Seong-Jeong;Hong, Byung-Pyo;Lee, Byoung-Soo;Byun, Hong-Sik
    • Applied Chemistry for Engineering
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    • v.21 no.5
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    • pp.527-531
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    • 2010
  • The optimized sheet for EMI shielding was prepared by metal power with Fe series. Then various metal powders were deposited on the sheet by PVD method. Moreover, the PVdF nanofiber membrane was used to compare the characteristic of EMI shielding efficiency of various metal powders. The electrical property was measured by the 4-point probe method. The result from EDS confirmed that the metal powder existed on the sheet. EMI shielding efficiency was analysed by EMI shielding measurement apparatus. The lowest electrical resistance, $641.95{\Omega}{wcdot}cm$, was obtained with $1000\;{\AA}$ deposition of Cu on the sheet. It was revealed that the EMI shielding efficiency increased with increase of the metal deposition thickness. The sheet deposited by Cu with $1000\;{\AA}$ showed the highest EMI shielding efficiency, 32.5 dB.

Study on the Electromagnetic Shielding of Accessory Device without Electromagnetic Shielding Technology in the Magnetic Resonance Room (자기공명검사실 내 전자기파 차단이 이루어지지 않은 부속장치의 차폐에 관한 연구)

  • Son, Soon-Yong
    • The Journal of the Korea Contents Association
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    • v.21 no.2
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    • pp.431-436
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    • 2021
  • In this study, a new shielding method was applied to an accessory device that produces electromagnetic waves in the magnetic resonance room to prevent the generation of artifact caused by electromagnetic waves. The research method applied a new shielding made of metal plating fiber to patient surveillance CCTVs without shielding technology, and obtained and evaluated noise map when the power was not cut off and when the new shielding technology was applied without shutting down the CCTV. As a result of the study, it was found that there was at least one group with significant differences. Type I and type III belonged to group 1 while type II belonged to group 2 in the Post-hoc analysis, which meant blocking power of the CCTV and the applying new shielding technology were in the same group. In conclusion, if electromagnetic waves are generated due to additional accessories in the scanning room, the shielding material proposed in this study should be applied which enables the electric state become similar to type I, not generating noise, thereby preventing the artifacts caused by electromagnetic waves.

Development and Performance Comparison of Silicon Mixed Shielding Material (실리콘 혼합 차폐체의 개발과 성능비교)

  • Hoi-Woun Jeong;Jung-Whan Min
    • Journal of radiological science and technology
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    • v.46 no.3
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    • pp.187-195
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    • 2023
  • A shield was made by mixing materials such as bismuth(Bi) and barium(Ba) with silicon to evaluate its shielding ability. Bismuth was made into a shield by mixing a bismuth oxide(Bi2O3) colloidal solution and a silicon base and applied to a fibrous fabric, and barium was made by mixing lead oxide(PbO) and barium sulfate(BaSO4) with a silicon curing agent and solidifying it to make a shield. The test was conducted according to the lead equivalent test method for X-ray protective products of the Korean Industrial Standard. The experiment was conducted by increasing the shielding body one by one from the test condition of 60 kVp, 200 mA, 0.1sec and 100 kVp, 200 mA, 0.1 sec. At 60 kVp, 2 lead oxide-barium sulfate shields, 2 bismuth oxide 1.5 mm shields, and 5 bismuth oxide 0.3 mm shields showed shielding ability equal to or higher than that of lead 0.5 mm. At 100 kVp, 2 lead oxide-barium sulfate shields and 2 bismuth oxide 1.5 mm shields showed shielding ability equal to or higher than that of lead 0.5 mm. It was confirmed that when using 2 pieces of lead oxide-barium sulfate and 1.5 mm of bismuth oxide, respectively, it has shielding ability equivalent to that of lead. Bismuth oxide and lead oxide-barium sulfate are lightweight and have excellent shielding ability, thus they have excellent properties to be used as an apron for radiation protection or other shielding materials.

Fabrication and Characteristics of Resin-Type Neutron Shielding Materials for Spent Fuel Shipping Cask (사용후핵연료 수송용기에 사용될 수지계 중성자 차폐재 제조 및 특성)

  • Cho, Soo-Haeng;Do, Jae-Bum;Ro, Seung-Gy;Do, Chun-Ho
    • Applied Chemistry for Engineering
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    • v.7 no.3
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    • pp.597-604
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    • 1996
  • Resin-type neutron shielding materials, KNS-115A, 115B and 115C have been fabricated to be used for spent fuel shipping cask. The base material is epoxy resin, and polypropylene, aluminium hydroxide and boron carbide are added. These shielding materials offer good fluidity at processing, which makes it possible to apply this resin shield to complicated geometric shapes such as shipping cask. Several measurements were made for the shielding materials to evaluate the shielding property, combustion characteristics, fire resistance, thermal and mechanical properties. The neutron shielding ability of the shielding materials is estimated to be better than that of foreign's shielding material, NS-4-FR, due to higher hydrogen atomic density. Other properties of the shielding materials are as follows: Onset temperatures; $267{\sim}270^{\circ}C$, thermal conductivities; $0.62{\sim}0.72W/m{\cdot}K$, combustion characteristics; <$800^{\circ}C$, ATB(average time of burning); <5sec, AEB(average extent of burning) ; <5mm, tensile strengths; $2.3{\sim}3.0kg/mm^2$, compressive strengths; $5.3{\sim}13.3kg/mm^2$, flexural strengths; $4.4{\sim}5.4kg/mm^2$.

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The Relationship of the Filtration and the Side-scattered Dose in Verious Radiation Shielding Materials (방사선차폐물질(放射線遮蔽物質)에서 발생(發生)하는 측방산란선(側方散亂線)의 측정(測定))

  • Huh, Joon;Kim, Chang-Kyun
    • Journal of radiological science and technology
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    • v.7 no.1
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    • pp.35-40
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    • 1984
  • Side-direction scattered dose from various radiation shielding materials was measured at 50cm distance from the central beam of primary ray by used several kinds of added filters for a x-ray deep therapeutic installation, the obtained results were as follows : 1. Dose rate by tube voltage was more increased at heavy filtration than light filtration. 2. Scattered doses produced by constant tube voltage in all shielding materials were decreased at heavier filtration. 3. Scattered doses produced by constant shielding material in all tube voltages were decreased at heavier filtration.

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X-ray and gamma ray shielding behavior of concrete blocks

  • Hernandez-Murillo, Christian Geovanni;Contreras, J. Rafael Molina;Escalera-Velasco, Luis Alberto;de Leon-Martineza, Hector Asael;Rodriguez-Rodriguez, Jose Antonio;Vega-Carrillo, Hector Rene
    • Nuclear Engineering and Technology
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    • v.52 no.8
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    • pp.1792-1797
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    • 2020
  • The shielding characteristics of two concrete blocks, widely used in the building industry in Mexico have been determined. These characteristics include the mass interaction coefficients, the linear attenuation coefficients and the half-value layers. The energy-dispersed X-ray fluorescence shows that the percentage mass content of each atom in the sample, and the atomic volume of the constituent elements of a material, plays an important role in its shielding capabilities. The total linear attenuation coefficients and the half-value layers were analyzed for a set of photon energies related to X-rays for diagnosis and cancer treatment with linear accelerators. Our results show that the concrete blocks have similar photon attenuation coefficients than the Portland concrete and better features than gypsum.

A Literature Review and Experimental Study of Basic Physical Properties about Electromagnetic Shielding Concrete Development (전자파 차폐용 콘크리트 개발에 관한 문헌조사 및 기초물성 연구)

  • Choi, Hyun-Jun;Choi, Hyun-Kuk;Lim, Sang-Woo;Lee, Han-Seung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2016.05a
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    • pp.41-42
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    • 2016
  • In this study, the basic properties of concrete with entrained materials as shielding material for electromagnetic pulse(EMP) within 10kHz~1GHz were investigated. The concretes of moderate strength were prepared with different entrained materials. The shielding effectiveness will be determined according to MIL-STD-188-125-1 at 28 days of concrete curing. The results of physical properties were all satisfied of setting criteria.

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Evaluation of Neutron Shielding Performance of Polyethylene Coated Boron Carbide-Incorporated Cement Paste using MCNP Simulation (MCNP 시뮬레이션을 통한 폴리에틸렌 코팅 탄화붕소 혼입 시멘트 페이스트의 중성자 차폐 성능 평가)

  • Park, Jae-Yeon;Jee, Hyeon-Seok;Bae, Sung-Chul
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2018.11a
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    • pp.114-115
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    • 2018
  • To develop an effective shielding material for spent fuel that emits fast neutrons is necessary. In this study, thermal neutron and fast neutron shielding performance of polyethylene coated boron carbide-incorporated cement paste was quantitatively analyzed by Monte Carlo N-Particle transport code (MCNP) simulations. As the results of the simulations, fast neutrons were effectively shielded through large quantity of hydrogen and boron elements in polyethylene and boron carbide.

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Distinct properties of tungsten austenitic stainless alloy as a potential nuclear engineering material

  • Salama, E.;Eissa, M.M.;Tageldin, A.S.
    • Nuclear Engineering and Technology
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    • v.51 no.3
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    • pp.784-791
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    • 2019
  • In the present study, a series of tungsten austenitic stainless steel alloys have been developed by interchanging the molybdenum in standard SS316 by tungsten. This was done to minimize the long-life residual activation occurred in molybdenum and nickel after decommissioning of the power plant. The microstructure and mechanical properties of the prepared alloys are determined. For the sake of increasing multifunction property of such series of tungsten-based austenitic stainless steel alloys, gamma shielding properties were studied experimentally by means of NaI(Tl) detector and theoretically calculated by using the XCOM program. Moreover, fast neutrons macroscopic removal cross-section been calculated. The obtained combined mechanical, structural and shielding properties indicated that the modified austenitic stainless steel sample containing 1.79% tungsten and 0.64% molybdenum has preferable properties among all other investigated samples in comparison with the standard SS316. These properties nominate this new composition in several nuclear application domains such as, nuclear shielding domain.