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1
Content available remote

Low Background CdWO₄ Scintillation Detector

100%
Kasperovych D., Danevich F., Kobychev V., Kropivyansky B., Tymoshenko A.
Acta Physica Polonica A
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2018
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vol. 133
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issue 4
923-927
EN
Low background scintillation setup has been developed that exhibits 3 orders of magnitude lower counting rate of a large volume (2.1 kg) CdWO₄ detector in the energy region 0.5-2.6 MeV, and one order of magnitude above 3 MeV. The background reduction was achieved by application of radiopure passive shield, active plastic-scintillation muon veto placed above the setup and pulse-shape discrimination. Construction of additional plastic scintillation counters is in progress to reduce the residual cosmic muons background. The setup can be applied to develop radiopure scintillators, measure radioactive contamination of materials, carry out small scale low counting experiments.
2
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Variation of Energy Resolution with Distance for a NaI(Tl) Detector

100%
Akkurt İ., Arda S., Gunoglu K.
Acta Physica Polonica A
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2015
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vol. 128
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issue 2B
B-422-B-423
EN
As the nuclear radiation has started to be used in a variety of different fields, it is important to be protected from it, and thus the radiation measurement becomes vital. The quality of the performance of a detection system, used for the energy measurements, is important. It is characterized by the width of the pulse-height distribution, obtained for the particles of the same energy (monoenergetic source). The energy spectrum of a radiation source depends on the type and energy of the incident particle and the type of the detector. In this work the energy resolution of a 3"×3" NaI(Tl) detector has been measured for photon energies of 511, 662, 835, 1173, 1275, and 1332 keV, and its variation with the detector-source distance was investigated. The energy resolution of a detector system is obtained from the peak full width at one-half of the maximum height (FWHM) of a single peak (for a particular energy) as a function of detector-source distance. It was found that the energy resolution has decreased with the increasing distance.
3
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Photon Attenuation Coefficients of Iron Doped Clay at 662~keV

100%
Akkurt I., Mavi B., Gunoglu K., Akyıldırım H., Canakci H.
Acta Physica Polonica A
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2013
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vol. 123
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issue 2
343-344
EN
After discovery of the radioactivity by Becquerel, radiation started to be used in large fields and it became part of our life nowadays. Using radiation from industry to medicine brings its hazardous effect and radiation protection developed in physics in parallel with the utilization of radiation. Although time, distance and shielding are the main rules to be protected from radiation, shielding is most effective way. In this case development of shielding materials becomes important. Clay is an interesting material and besides using it for different purposes it can be used as plaster material in building construction. In this study iron doped into clay samples and radiation shielding properties has been measured at 662 keV gamma rays. The measurements have been performed using gamma spectrometer system which contains NaI(Tl) and 16k multichannel analyser.
4
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Cement Paste as a Radiation Shielding Material

100%
Akkurt İ., Günoğlu K., Başyiğit C., Kılınçarslan Ş., Akkaş A.
Acta Physica Polonica A
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2013
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vol. 123
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issue 2
341-342
EN
Cement, mainly, natural limestone and clay mixture after being heated at high temperature is obtained by milling and it is defined as a hydraulic binder material. Especially, cement is used in production concrete. The photon attenuation coefficient (μ, cm^{-1}) for cement paste has been measured using gamma spectrometer containing NaI(Tl) detector and MCA at 835, 1173, and 1332 keV. Cement paste was prepared with types of Portland cement which is CEM I 52,5 R- and CEN reference sand has been used according to TS EN 196-1 standard. The mass attenuation coefficients have been calculated at photon energies of 1 keV to 100 GeV using XCOM and the obtained results were compared with the measurements at 835, 1173, and 1332 keV.
5
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Optimization of Positron-Lifetime Measurement Geometry Based on Geant4 Simulation

100%
Saro M., Petriska M., Slugeň V.
Acta Physica Polonica A
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2017
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vol. 132
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issue 5
1634-1636
EN
Proper choice of measuring geometry and experimental setup of nuclear instrumentation modules and photomultipliers is a key element which affects substantial positron lifetime measurement properties: count rate and time resolution. An adequate compromise must be found, when it comes to geometry of measurement. The optimal geometry using three detector layout is inspected in this paper. During our work, we concentrated on the simulation of XP2020Q photomultipliers and the BaF₂ scintillator material. The Geant4 simulation allows to estimate an influence of the measuring geometry on detection efficiency and to choose the most appropriate crystals dimensions and positions. As mentioned in paper of Bečvaŕ et al., slight changes in geometry result in distortion or improvement of measured results. Experimental results already showed, changes of start crystals dimensions can result in significant increase in count rate of three-detector measurement.
6
Content available remote

Determination of Radiation Attenuation Coefficients of Concretes in Different Densities

100%
Akkurt İ., Günoğlu K., Başyiğit C., Akkaş A.
Acta Physica Polonica A
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2013
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vol. 123
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issue 2
374-375
EN
The density of the concrete is important parameter for different properties. Using different types and rates of aggregates cause different densities of the concretes. Radiation shielding properties can be varied with the density and it is important to obtain optimum density for this purpose. In this study radiation attenuation coefficients were measured by comparison of five different densities of concrete that called lightweight, semi-lightweight, ordinary and semi-heavyweight and heavyweight. For this purpose concretes were produced with suitable aggregate in laboratory conditions and determined some physical and mechanical properties. The total linear attenuation coefficient measurements have been obtained by a collimated beam of gamma ray from sources ^{60}Co.
7
Content available remote

Characterization of Concave-Curved Spectrometers for 2D X-Ray Optics

100%
Chukhovskii F. N., Chang W. Z., Förster E.
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EN
A procedure for calculating X-ray intensity profiles analytically for various X-ray diffraction geometries has been developed, which takes into account the misalignment, the solid angle factor, the effects of convergence and/or divergence of the diffracted X-rays. The approach is applicable to X-ray optics with either a point source or a quasi-parallel beam. Moreover, using this procedure allows one to calculate the magnified image from a plasma source, the intensity profiles of topographs of bent crystals, and the spectral resolution of various focusing geometries. Several examples are presented to demonstrate the applications of this procedure. Using non-dispersive and dispersive double-crystal spectrometers, rocking curves were measured for singly and doubly bent crystals. The agreement was satisfactory with the X-ray dynamic theory of bent crystals. Furthermore, we have also extended the study of X-ray optics to include the crystal anisotropic effects. The anisotropic elasticity theory is applied to bend crystals for calculating the diffracting region on the crystal surface. The anticlastic curvature effects are analytically demonstrated with respect to the crystals' diffracting area.
8
Content available remote

Radiation Shielding Properties of Shotcrete

100%
Gunoglu K., Akkurt I., Basyigit C., Çakıroğlu M., Akkaş A.
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vol. 125
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issue 2
299-300
EN
Shotcrete is a concrete spraying of concrete or mortar that may be accomplished through either a dry- or wet-mix process. It is made of normal weight aggregates which have a density of approximately 2323 kg/m^3. For the most part, shotcrete is used in underground excavations in rock and repair work in constructions. In this study, linear attenuation coefficient (μ, cm^{-1}) was measured for shotcrete produced with dry mix process. Measurements were carried out by gamma spectrometry containing NaI(Tl) detector and multichannel analyzer.
9
Content available remote

Radioactivity Measurement on Dental Resin Composites

80%
Akkurt İ., Ermiş R., Baş P., Günoğlu K.
Acta Physica Polonica A
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2015
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vol. 128
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issue 2B
B-34-B-36
EN
Radioactivity is mainly due to natural ones from earth and also from outside of the atmosphere so-called cosmic radiation. Although radiation sources and their dose effect on humans are known, there is still some conflict on their health effect especially on dental restoration. The limited data for radioactive dental materials and their potential risks for patient makes those materials interesting to be investigated. For this purposes, uranium, thorium and potassium activity have been measured in some dental restorative materials, such as resin composites containing silica and zirconia particles as filler loading, using gamma spectrometer system with NaI(Tl) detector.
10
Content available remote

Determination of the Tenth and Half Value Layer Thickness of Concretes with Different Densities

80%
Akkaş A.
Acta Physica Polonica A
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2016
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vol. 129
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issue 4
770-772
EN
Half value layer (HVL) is the most frequently used quantitative factor for describing both the penetrating ability of specific radiations and the penetration through specific objects. The half value layers (HVL) and tenth value layers (TVL) are defined as the thickness of a shield or an absorber that reduces the radiation level by a factor of one-half and one tenth of the initial level, respectively. The concepts of HVL and TVL are widely used in shielding design. They are photon energy dependent, like the attenuation coefficient. HVL and TVL values provide useful information about the penetration of a specific radiation in a specific material. In this study, TVL and HVL thickness are calculated for concretes with different densities. For this purpose five types of concrete with different density ranges were selected, with densities between 600-1500 kg/m^{3}, called lightweight concrete, 1400-2000 kg/m^{3}, called semi lightweight concrete, 2000-2500 kg/m^{3} called ordinary concrete, 2500-3000 kg/m^{3}, semi heavyweight concrete and 3000-4000 kg/m^{3} called heavyweight concrete, respectively. For evaluated TVL and HVL thicknesses, the linear attenuation coefficients μ, were determined from measurements, using a collimated beam of gamma rays from a Cobalt-60 source.
11
Content available remote

Evaluation of Multiple Backscattering and Saturation Thickness of Gamma Rays

80%
Akar Tarim U.
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EN
A Monte Carlo code was written to determine the saturation thickness for multiply scattered gamma rays from aluminium targets. Interactions of incident gamma rays with the energies of 123, 279, 360, 511, 662, 1115, and 1250 keV were simulated. This work aims to design a convenient code which can be used in investigations on gamma backscattering. Obtained results for saturation thickness values have been compared with experimental ones and the Monte Carlo N-particle (MCNP) code results, and showed good agreement. Also, based on the similar behavior of number of multiple scattered photons between these three methods, the expected spectrum of singly or multiply scattered photons which is not possible to observe with experiment has been presented.
12
Publication available in full text mode
Content available

Ion Microscopy and Tomography

80%
Butz T., Lehmann D., Reinert T., Spemann D., Vogt J.
Acta Physica Polonica A
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2001
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vol. 100
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issue 5
603-613
EN
The use of light ions for microscopy and tomography is illustrated by a variety of recent applications in materials and life sciences at the Leipzig high-energy ion-nanoprobe LIPSION with a short comparison to other microscopic techniques. The versatility of ion techniques is exemplified by Rutherford backscattering spectrometry maps of thin films of solar cell materials, particle induced X-ray emission maps of manganese in ancient human bones, particle induced X-ray emission on single aerosol particles withμm size, and scanning transmission ion microscopy and tomography on pigs knee cartilage. Finally, the design of a single ion single living cell bombardment facility is sketched for studies of the cellular response and microdosimetry.
13
Content available remote

Production of Barite and Boroncarbide Doped Radiation Shielding Polymer Composite Panels

70%
Evcın O., Evcın A., Bezır N., Akkurt İ., Günoğlu K., Ersoy B.
Acta Physica Polonica A
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2017
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vol. 132
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issue 3
1145-1148
EN
Developments in nuclear technology in the last century have lead to the use of radiation in different areas of human activity. These are not just the energetics but also food, agriculture, medicine, industry and science. Thus, radiation has become an inevitable phenomenon in our lives. Since we cannot isolate radiation from our life, the radiation protection methods should be available. As alternatives to conventional radiation prevention methods, such as lead and heavy concrete shielding, more functional materials need to become the focus of research. The development of the least harmful to the environment, easily applicable, flexible radiation shields has become very important. In this study, silicon matrix composite panels, doped with different ratios of barite and boron carbide, were produced and characterized by optical and scanning electron microscopy (SEM). Gamma and neutron radiation shielding properties of these materials were investigated. The results have been compared with the lead as the standard shielding material.
14
Content available remote

At the Tip of an MeV Beam: Provoking Cells and Performing Tomographic Imaging

51%
Pallon J., Arteaga-Marrero N., Nilsson C., Elfman M., Kristiansson P., Nilsson C., Wegdén M., Olsson M., Åkerström B.
Acta Physica Polonica A
|
2009
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vol. 115
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issue 2
501-506
EN
Biological applications of ion beams have recently become a new important research field using single ion hit facilities to study individual living cells and their response to the hit of a counted number of ions. One motivation is the search for a better understanding of the fundamental processes taking place in cells and organs as a result of irradiation. Another comes from the increasing interest in using high energy protons and heavy ions as a modality for radiotherapy of deep seated tumours. In the view of treatment efficiency, study of cell culture behaviour under controlled radiation experiments, and in different chemical environments at single ion hit facilities, is a first step towards a better understanding of the processes. Tomographic techniques are applicable to situations where you need information of the inside of an object but do not want to section it into thin slices or cannot do it. Using focused MeV ion beams for tomography restricts the sample size to the order of 10-100 μm, depending of the initial energy. On the other hand, the ability to focus at a sub-micrometer level makes ion beams well suited for analyses of small sized objects as cells, spores, etc. The scanning transmission ion microscopy mode of tomography gives the mass density and corresponding morphological structure of holes and pores. It can then be used to correct the results from the other mode, particle induced X-ray emission tomography. Here is discussed a porosity analysis of bentonite clay that is planned to form an important buffer zone around canisters filled with spent nuclear reactor fuel waste deposited 500 m underground in Sweden.
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