Yazar "Dilsiz, K." seçeneğine göre listele
Listeleniyor 1 - 9 / 9
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe A comparative neutron and gamma-ray radiation shielding investigation of molybdenum and boron filled polymer composites(Pergamon-Elsevier Science Ltd, 2023) Ogul, H.; Agar, O.; Bulut, F.; Kacal, M. R.; Dilsiz, K.; Polat, H.; Akman, F.This work presents a detailed radiation shielding study for polymer composites filled with Boron and Molyb-denum additives. The chosen novel polymer composites were produced at different percentages of the additive materials to provide a proper evaluation of their neutron and gamma-ray attenuation abilities. The effect of additive particle size on the shielding characteristics was further investigated. On the gamma-ray side, simula-tion, theoretical and experimental evaluations were performed in a wide range of photon energies varying from 59.5 keV to 1332.5 keV with help of MC simulations (GEANT4 and FLUKA), WinXCOM code, a High Purity Germanium Detector, respectively. A remarkable consistency was reported between them. On the neutron shielding side, the prepared samples produced with nano and micron particle size additives were additionally examined by providing fast neutron removal cross-section (sigma R) and the simulated neutron transmissions through the prepared samples. The samples filled with nano sized particles show better shielding capability than the one filled with micron sized particles. In other words, a new polymer shielding material that does not contain toxic content is introduced: the sample codded N-B0Mo50 exhibits superior radiation attenuation.Öğe A detailed investigation of gamma and neutron shielding capabilities of ternary composites doped with polyacrylonitrile and gadolinium (III) sulfate(Pergamon-Elsevier Science Ltd, 2023) Erkoyuncu, I. .; Akman, F.; Ogul, H.; Kacal, M. R.; Polat, H.; Demirkol, I.; Dilsiz, K.The shielding efficiencies of gamma and neutron radiations for ternary composites containing polyester resin, polyacrylonitrile and gadolinium (III) sulfate at different ratios were investigated in the present study. In order to investigate the gamma radiation shielding capacity of the produced ternary composites, linear and mass atten-uation coefficients, half value layer, effective atomic number and radiation protection efficiency parameters were determined experimentally, theoretically and using the GEANT4 simulation code. The gamma shielding capa-bilities of the composites were studied in the photon energy range of 59.5-1332.5 keV. In order to investigate the neutron shielding abilities of composites, inelastic, elastic, capture and transport numbers, total macroscopic cross section and mean free path parameters were determined with the help of GEANT4 simulation code. In addition, the number of transmitted neutrons at different sample thicknesses and neutron energies were also determined. It was observed that gamma radiation shielding properties were improved due to the increasing amount of gadolinium (III) sulfate and neutron shielding properties were improved due to the increasing amount of polyacrylonitrile. While the composite coded P0Gd50 exhibits a better gamma radiation shielding ability than the others, the neutron shielding of the sample coded P50Gd0 is also more favorable than the others.Öğe Characterization of photomultiplier tubes in a novel operation mode for Secondary Emission Ionization Calorimetry(Iop Publishing Ltd, 2016) Tiras, E.; Dilsiz, K.; Ogul, H.; Southwick, D.; Bilki, B.; Wetzel, J.; Nachtman, J.Hamamatsu single anode R7761 and multi-anode R5900-00-M16 Photomultiplier Tubes have been characterized for use in a Secondary Emission (SE) Ionization Calorimetry study. SE Ionization Calorimetry is a novel technique to measure electromagnetic shower particles in extreme radiation environments. The different operation modes used in these tests were developed by modifying the conventional PMT bias circuit. These modifications were simple changes to the arrangement of the voltage dividers of the baseboard circuits. The PMTs with modified bases, referred to as operating in SE mode, are used as an SE detector module in an SE calorimeter prototype, and placed between absorber materials (Fe, Cu, Pb, W, etc.). Here, the technical design of different operation modes, as well as the characterization measurements of both SE modes and the conventional PMT mode are reported.Öğe Gamma and Neutron Shielding Parameters of Polyester-based composites reinforced with boron and tin nanopowders(Pergamon-Elsevier Science Ltd, 2022) Ogul, H.; Polat, H.; Akman, F.; Kacal, M. R.; Dilsiz, K.; Bulut, F.; Agar, O.The usage of composites as the shielding materials are highly recommended since they could be used in order to attenuate the undesired radiation with unique properties and advantages in the areas where the radiation is prevalent. In this context, not only are their radiation shielding properties important but also their flexibility, durability and low cost. Due to the mentioned superior characteristics, the polyester based composites are among the most preferred materials. With the aim of creating unique and novel radiation shielding materials, this study investigates gamma and neutron shielding capabilities of the polyester composites reinforced with Boron and Tin nanopowders at different proportions (0-50%, 10-40%, 20-30%, 30-20% and 40-10%, 50-0%). The gamma shielding abilities of the prepared polyester composite materials were evaluated using an HPGe detector system, WinXCOM computer program and different simulation tools (FLUKA and GEANT4) at the energies varying from 59.5 to 1332.5 keV. The experimental, theoretical and simulation results showed remarkable agreement between each other, and the addition of Sn enhances the gamma attenuation performance of the chosen polyester composite materials. In addition to gamma analysis results, neutron shielding properties of the proposed com-posites are further determined. On this purpose, the transmitted neutron numbers through the samples (as functions of neutron energy and the sample thickness) and effective neutron removal cross sections were eval-uated. The neutron shielding performance of the samples showed that the prepared composites could be alter-native materials to the existing neutron shields in the literature.Öğe Gamma attenuation characteristics of CdTe-Doped polyester composites(Pergamon-Elsevier Science Ltd, 2021) Akman, F.; Ogul, H.; Kacal, M. R.; Polat, H.; Dilsiz, K.; Agar, O.Polyester is strong and durable material and tends to retain its shape, thus polyester composites have become highly preferred option in high-tech applications. This motivates the usage of polyester composites in the production of radiation shielding materials as well. In present study, gamma ray shielding properties of polyester composite reinforced with different proportions of Cadmium Telluride (5%, 10%, 15% and 20%) have been investigated theoretically and experimentally. The experiments were performed with the use of HPGe detector in a wide range of photon energies varying from 59.5 to 1408.0 keV while XCOM computer program was computed in the same photon energy range to obtain theoretical results and to verify the experimental outcomes. Remarkable radiation protection efficiency was obtained with additive material of Cadmium Telluride, and the radiation protection efficiency was found to be increased with the increase of additive material amount. Negligible discrepancies between experimental and theoretical results were also observed.Öğe Impact of lead(II) iodide on radiation shielding properties of polyester composites(Springer Heidelberg, 2020) Akman, F.; Ogul, H.; Kacal, M. R.; Polat, H.; Dilsiz, K.; Turhan, M. F.This paper investigates the radiation shielding properties, such as linear and mass attenuation coefficients, half and tenth value layers, effective atomic number and electron density, and radiation protection efficiency as a function of photon energy, of a new composite, PbI2-doped polyester. The mentioned polyester composite was prepared with different proportions of lead(II) iodide (5% increments between 5 and 20%) so that impact of the dopant amount on radiation shielding could be properly analyzed. The prepared composites were tested in 22 different energies in the energy range of 59.5-1408.0 keV with the use of HPGe detector and eight radioactive point sources. The obtained results were further validated by comparing the results of XCOM computer program, and negligible discrepancies were observed. It was observed that PbI2 (20%) composite is more effective gamma radiation shielding material than other produced composites. In light of this information, it can be said that the shielding efficiency increases with increasing lead(II) iodide amount.Öğe Micro Pb filled polymer composites: Theoretical, experimental and simulation results for γ-ray shielding performance(Pergamon-Elsevier Science Ltd, 2022) Kilicoglu, O.; V. More, Chaitali; Akman, F.; Dilsiz, K.; Ogul, H.; Kacal, M. R.; Polat, H.Researches on advanced composites to protect environment health towards radioactive pollution have drawn attention with the rising use of radioactive elements. From this point, polymer micro composites are quite encouraging in terms of multifunctional properties in mechanical, electrical, thermal, as well as nuclear shielding. The present study has explored the efficacy of micro lead (Pb) loaded polymer composites for radio protective applications such as a fabrication of protective enclosures. High energetic photon shielding experiments have been applied through gamma spectrometer equipped with HPGe detector and various radioactive point sources namely 137Cs, 22Na, 152Eu, 133Ba, 241Am and 57,60Co which are widely used in several medical and industrial applications. The results demonstrated that mass attenuation coefficients of the composites at different photon energies are proportional to the filler loading. The validation of FLUKA and GEANT4 Monte Carlo software has been performed in the simulation of transmission experiments as well as WinXCOM software. The tests of the Pb (20%) micro composite for the nuclear radiation shielding reveal that it has high attenuation coefficients for photon radiation.Öğe Secondary Emission Calorimetry(Institute of Electrical and Electronics Engineers Inc., 2022) Bilki, B.; Dilsiz, K.; Ogul, H.; Onel, Y.; Southwick, D.; Tiras, E.; Wetzel, J.In high-radiation environments, electromagnetic calorimetry is particularly challenging. To address this, a feasible approach involves constructing a sampling calorimeter that employs radiation-hard active media, albeit at the expense of high energy resolution. In response, we developed an innovative technique, secondary emission calorimetry, which offers radiation resistance, rapid response, robustness, and cost-effectiveness. Our efforts involve the creation of prototype secondary emission sensors, subjected to comprehensive testing within test beams. In the secondary emission detector module, incident charged hadrons or electromagnetic shower particles trigger the generation of secondary emission electrons from a cathode. These generated electrons are subsequently amplified in a manner similar to the process within photomultiplier tubes. This report provides an insight into the principles underlying secondary emission calorimetry, presents findings from beam tests, and outlines Monte Carlo simulations that project towards the potential application of large-scale secondary emission electromagnetic calorimeters. © 2022 IEEE.Öğe Study on gamma radiation attenuation and non-ionizing shielding effectiveness of niobium-reinforced novel polymer composite(Korean Nuclear Soc, 2022) Akman, Ferdi; Ogul, H.; Ozkan, I; Kacal, M. R.; Agar, O.; Polat, H.; Dilsiz, K.Advanced radiation applications have been widely used and extended to many fields. As a result of this fact, choosing an appropriate shielding material based on the radiation application has become vital. In this regard, the integration of elements into polymer composites has been investigated and contributed to the quantity and quality of radiation shielding materials. This study reports photon attenuation parameters and electromagnetic shielding effectiveness of a novel polymer composite prepared with a matrix reinforced with three different proportions (5,10, and 15 wt%) of niobium content. Addition of Nb dopant improves both photon attenuation and electromagnetic shielding effectiveness for the investigated composites. Therefore, Nb(15%) polymer composite with highest concentration has been found to be the best absorber for ionizing and non-ionizing radiations. Consequently, the performed analyzes provide evidences that the prepared Nb-reinforced polymer composite could be effectively used as photon radiation attenuator and electromagnetic shielding material. (c) 2021 Korean Nuclear Society, Published by Elsevier Korea LLC. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
