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Przemysłowe akceleratory elektronów i ich zastosowania w technologiach radiacyjnych : radiacyjnie indukowane procesy chemiczne, radiacyjnie wspomagana obróbka składników opon samochodowych

Bułka Stanisław

Elektronika : konstrukcje, technologie, zastosowania

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2024

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Vol. 65, Nr 4

17--20

PL

Technologia napromieniowania wiązką elektronów (EBR) jest jedną z najbardziej obiecujących technologii spośród innych technik wykorzystujących promieniowanie i jest stosowana w przemyśle gumowym i oponiarskim ze względu na jej zdolność do sieciowania niektórych kauczuków w zależności od ich struktury chemicznej. EBR może zapewnić dobrą wytrzymałość początkową gumy i wyrobów gumowych poprzez częściowe usieciowanie, co ma praktyczne znaczenie w procesie budowy opon radialnych. Elementy opon, w których EBR ma praktyczne zastosowanie, obejmują bieżniki opon, wykładziny wewnętrzne, pasy i mieszanki warstwowe nadwozia. Pokazano wpływ EBR na strukturę i właściwości gum oponowych, takich jak kauczuk naturalny (NR), poli-butadien. Podkreślono także zasadność zastosowania tego procesu we współczesnym przemyśle oponiarskim.

EN

Electron beam radiation (EBR) technology is one of the most promising technologies among other radiation-driven technologies and has been used in the rubber and tyre industry due to its ability to cross-link certain rubbers depending on their chemical structures. EBR can provide good green strength to rubber and rubber products by partial cross-linking which has practical importance in the radial tyre building process. The tyre components where EBR has practical application include tyre treads, inner liners, belt, and body ply skim compounds. The effect of EBR on the structure and properties of tyre rubbers, such as natural rubber (NR), polybutadiene rubber (BR). The viability of the application of this process in the modern-day tyre industry is also highlighted.

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On the prognosis of the growth of a heterostructure from a gas phase to analyze the possibility of decreasing mismatch-induced stresses

Pankratov Evgeny L.

Computer Methods in Materials Science

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2021

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Vol. 21, No. 2

105--122

EN

An approach to decreasing mismatch-induced stress in a heterostructure by radiation processing during growth from the gas phase is introduced in this paper. Within the framework of the approach with decreasing mismatch-induced stresses, one can find the acceleration of the recombination and diffusion of radiation defects generated during radiation processing. An analytical approach for analyzing mass and heat transfer is also introduced. The approach provides the opportunity to simultaneously take into account spatial and temporal variations of mass transfer parameters. At the same time, the approach allows the nonlinearity of the considered processes to be taken into account.

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Economical evaluation of radiation processing with high-intensity X-rays

Zimek Zbigniew

Nukleonika

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2020

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Vol. 65, No. 3

167--172

EN

X-rays application for radiation processing was introduced to the industrial practice, and in some circumstances is found to be more economically competitive, and offer more flexibility than gamma sources. Recent progress in high-power accelerators development gives opportunity to construct and apply reliable high-power electron beam to X-rays converters for the industrial application. The efficiency of the conversion process depends mainly on electron energy and atomic number of the target material, as it was determined in theoretical predictions and confirmed experimentally. However, the lower price of low-energy direct accelerators and their higher electrical efficiency may also have certain influence on process economy. There are number of auxiliary parameters that can effectively change the economical results of the process. The most important ones are as follows: average beam power level, spare part cost, and optimal shape of electron beam and electron beam utilization efficiency. All these parameters and related expenses may affect the unit cost of radiation facility operation and have a significant influence on X-ray process economy. The optimization of X-rays converter construction is also important, but it does not depend on the type of accelerator. The article discusses the economy of radiation processing with high-intensity of X-rays stream emitted by conversion of electron beams accelerated in direct accelerator (electron energy 2.5 MeV) and resonant accelerators (electron energy 5 MeV and 7.5 MeV). The evaluation and comparison of the costs of alternative technical solutions were included to estimate the unit cost of X-rays facility operation for average beam power 100 kW.

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Akceleratory elektronów stosowane w technice radiacyjnej (niezawodność, aspekty ekonomiczne)

Zimek Z.

Postępy Techniki Jądrowej

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2017

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z. 1

12--19

PL

Rozwój technologiczny akceleratorów stosowanych w technice radiacyjnej jest dobrze widoczny w dłuższej skali czasowej. Obecnie szczególnie intensywnie kontynuowane są prace mające na celu podniesienie sprawności elektrycznej akceleratorów, obniżenie ich ceny oraz podniesienie niezawodności. W niedalekiej przyszłości możliwy będzie transfer technologii z obszaru akceleratorów badawczych stosowanych w fizyce wysokich energii, co pozwali na konstrukcję innowacyjnych urządzeń poszerzających znacząco zakres możliwości technicznych i cenowych. Blisko 3000 akceleratorów elektronów znalazło do chwili obecnej zastosowanie w technice radiacyjnej, która wykorzystuje wiązkę elektronów jako narzędzie do inicjowania pożądanych reakcji chemicznych, modyfikacji materiałów, a także wykorzystuje biobójcze działanie promieniowania jonizującego. Ogromne możliwości upowszechnienia technologii radiacyjnych są związane z wykorzystaniem radiacyjnej obróbki produktów żywnościowych oraz zastosowaniem na szeroką skalę wiązki elektronów w instalacjach związanych z ochroną środowiska. Najliczniejszą grupą akceleratorów elektronów stosowanych w technice radiacyjnej są niskoenergetyczne akceleratory o działaniu bezpośrednim. Szczególną klasą urządzeń są akceleratory rezonansowe, umożliwiające uzyskanie wysokich energii oraz mocy wiązki elektronów. Znacznym osiągnięciem aplikacyjnym była konstrukcja i instalacja rezonansowego akceleratora typu Rhodotron z mocą wiązki 560 kW i energią elektronów 7 MeV, wyposażonego w konwertor wiązki elektronów na promieniowanie hamowania. Urządzenie tego typu stanowi ekwiwalent źródła gamma o aktywności 4,4 MCi gamma Co60. Niezawodność czyli prawdopodobieństwo, że akcelerator może pełnić swoje funkcje w określonym czasie w wyznaczonych warunkach, oraz dostępność czyli czas, w którym akcelerator wypełnia swoje zadania to parametry, które w zastosowaniach przemysłowych nabierają podstawowego znaczenia. Wyroby modyfikowane radiacyjnie muszą spełniać wszystkie kryteria przydatności zgodnie z oczekiwaniami rynku, a jednocześnie technologie radiacyjne muszą wykazać się lepszymi wskaźnikami techniczno- ekonomicznymi w porównaniu do konwencjonalnych technologii aktualnie istniejących. Stąd konieczność optymalizacji decyzji inwestycyjnych głównie z uwagi na wysokość kosztów związanych z zakupem akceleratora i jego eksploatacją. Konieczne jest prowadzenie nieustannych wysiłków dla zwiększenia zrozumienia przydatności technologii radiacyjnych, co może być ważnym czynnikiem wzrostu tego przemysłu. W obecnych warunkach współpraca z przemysłem staje się niezbędnym warunkiem inicjowania i rozwijania badań aplikacyjnych niezbędnych przy opracowaniu nowych technologii radiacyjnych.

EN

The development of the accelerator technology applied in the radiation processing is well visible in the longer time scale. The current issues are improvement of the electric efficiency of accelerators, the lowering of their price and elevation of accelerator reliability. The transfer of accelerator technology from the field of high energy physics is quite possible in the near future. It will allow to construct innovative devices and offer significantly better technical capabilities and unit price. Nearly 3000 accelerators of electrons have been applied in radiation processing up to now. The electron beam is used as the tool to initiating desirable chemical reactions, materials modification, and decontamination of the medical products. Huge capabilities to increase implementation of radiation processing may create electron beam utilization for food products decontamination and use on the wide scale the electron beams in processes connected with the protection of the environment. Low energy direct accelerators are the most numerous group of the electron accelerators applied in the radiation technique. Resonance accelerators are the special class of devices capable to reach high energy and beam power. The considerable achievement is construction and installation of the accelerator Rhodotron type with the beam power of 560 kW and the energy of electrons 7 MeV. The described accelerator was equipped with the X-ray converter. This device comprises a direct equivalent of the gamma source with the activity 4.4 MCi of Co60. Reliability that is the probability, that the accelerator can function in the definite time in appointed conditions. Accessibility is the time, in which the accelerator functions properly. Both parameters are becoming important for industrial facilities exploitation. Products modified by radiation have to fulfill all criteria of usefulness according to market expectations. Radiation technologies have to simultaneously be characterized by better technical and economic ratings in comparison with conventional technologies. Hence the necessity of the optimization of investment decisions related to costs connected with the accelerator purchase and exploitation. The efforts are necessary for enlargement of the understanding of the radiation processing usefulness what can be the important factor of this industry growth in future. The co-operation with the industry becomes the indispensable condition of initiating and unrolling applied study related to new radiation technologies development.

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Radiation processing for cultural heritage preservation : Romanian experience

Moise I. V., Ene M., Negut C. D., Cutrubinis M., Manea M. M.

Nukleonika

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2017

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Vol. 62, No. 4

253--260

EN

Radiation sterilization has been considered a mass decontamination technique for biodegradable cultural heritage (CH) since its widespread application in the medical field. Initial experiments have revealed advantages, for example, efficiency and effectiveness, but also disadvantages, namely “side effects” concerning CH materials. More than 50 years later, the adequacy of ionizing radiation for some CH artefacts is still the subject of discussion. The main reason why is that science and industry are not yet able to provide a more efficient technique for treating mass decontamination. For wooden items, there is general agreement that the irradiation dose required for insect eradication is not damaging, even in the case of polychromed wood. For cellulose pulp (paper), there is a reduction in polymerization degree (DP) at the high doses necessary to stop the attack of fungi, but this should be considered taking into account the purpose of the treatment. Emergency or rescue treatments are necessary to mitigate the consequences of accidents or improper storage conditions. In some cases (archives), the value of written information is greater than the historical value of the paper support. For other materials, namely textiles, leather and parchment, less research has been published on the effect of ionizing radiation treatment. As a general rule, irradiation is not necessary when only a few CH elements are present that are affected by biological contamination since restorers can solve the problem by classical means. The need for radiation treatment arises when large collections (hundreds, thousands or even more elements) are heavily affected by the biological attack. In Romania, the IRASM gamma irradiator of IFIN-HH is receiving an increasing number of requests for CH treatment, mainly due to an intensive research programme concerning this topic and close liaison with CH owners or administrators. Besides reviewing the scientific results obtained in Romania and abroad, this paper presents some examples from experiences in Romania.

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Evaluation of polymers designed for radiation processing

Przybytniak G., Nowicki A., Mirkowski K.

Nukleonika

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2008

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Vol. 53, suppl. 2

67--72

EN

Five types of commercially available polyethylene (PE) and some selected blends with components supporting cross-linking were radiation cross-linked. Mechanical properties and gel fraction were determined upon electron beam irradiation to such a dose that induces about 60% gel fraction. It was confirmed that for easily cross-linked PEs strength at break usually was growing and for polyethylenes less susceptible to radiation cross-linking – was reduced. Similar dependence was found for elongation at break. It was confirmed that for polyethylenes demonstrating high strength at break the efficiency of radiation cross-linking is limited. Additionally, for selected polymeric materials, stress relaxation and accelerated thermal aging were estimated. In order to enhance cross-linking yield some blends with EVA copolymer (ethylene-vinyl acetate) were prepared. On the basis of the literature data, the influence of crystalline regions on cross-linking and mechanical properties was discussed as well.

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Comparison of dichromate and ethanol-chlorobenzene dosimeters in high dose radiation processing

Šećerov B., Bačić G.

Nukleonika

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2008

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Vol. 53, No. 3

85-87

EN

Dichromate and ethanol-chlorobenzene dosimeters were studied in conditions of annual temperature changes during process control at the Radiation Unit of the Vinča Institute. Measurements were performed in February (10-14°C) and August (22-35°C) for the dose range 10-50 kGy. The difference between measurements using these dosimeters is in agreement with the previous laboratory studies of temperature effect on the dose response of a dichromate dosimeter. The absorbed doses measured by these two dosimeters are in good agreement and the difference is within a limit of 3% for the studied dose range. The uncertainties of dose measurements using dichromate dosimeter arising from irradiation during annual temperature changes appear to be well within acceptable limits indicating that this dosimeter can be used as a routine dosimeter.

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Radiation processing of polymers and semiconductors at the Institute of Nuclear Chemistry and Technology

Zimek Z., Przybytniak G., Kałuska I.

Nukleonika

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2006

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Vol. 51,suppl.1

129-132

EN

R&D studies in the field of radiation technology in Poland are mostly concentrated at the Institute of Nuclear Chemistry and Technology (INCT). The results of the INCT works on polymer and semiconductor modification have been implemented in various branches of national economy, particularly in industry and medicine. Radiation technology for polymer modification was implemented in the middle of the 1970-ties. Among others, the processes of irradiation and heat shrinkable products expansion have been developed. The transfer of this technology to Polish industry was performed in the middle of the 1980-ties. The present study aims at the formulation of new PE composites better suited to new generation of heat shrinkable products, for example, a new generation of hot-melt adhesives has been developed to meet specific requirements of customers. Modified polypropylene was used for the production of medical devices sterilized by radiation, especially disposable syringes, to overcome the low radiation resistance of the basic material. Modified polypropylene (PP-M) has been formulated at the INCT to provide material suitable for medical application and radiation sterilization process. Modification of semiconductor devices by EB was applied on an industrial scale since 1978 when the INCT and the LAMINA semiconductor factory successfully adopted that technology to improve specific semiconductor devices. This activity is continued on commercial basis where the INCT facilities served to contract irradiation of certain semiconductor devices according to the manufacturing program of the Polish factory and customers from abroad.

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Specific heat of selected graphites used in calorimetry of electron beam and its influence on the accuracy of measurement of large dose

Panta P., Głuszewski W.

Nukleonika

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2005

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Vol. 50,suppl.2

55-57

EN

Calorimetry is applicable to both absolute calibration of routine dosimeters and absolute measurements of electron beam (EB) intensity (for industrial radiation processing). Advantages of graphite as the absorbing calorimetric material are a good heat capacity and negligible heat defect of this material. Knowledge of the specific heat capacities of the calorimetric core materials is fundamental in making absolute dose measurements. Two kinds of high-purity graphite used in calorimeters were analysed, i.e. Union Carbide grade AGOT and nuclear grade graphite [10]. There are some differences of specific heat of these graphites, up to 2% , which influence dosimetric response of calorimeters made of them.

10

Mass throughput rate calculation for X-ray facilities

Ziaie F., Tahami S.

Nukleonika

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2005

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Vol. 50, nr 3

121-124

EN

Abstract In this work, the mass throughput rate in a radiation processing center, equipped with an X-ray facility, is calculated by means of a curve against the thickness of the material, along with the variation of dose uniformity. Therefore, depending on the desired dose value, the best thickness and the mass throughput rate can be calculated. The calculation results for the 5 and 10 MeV X-ray bremsstrahlung for polyethylene and wood as the irradiation products, have been obtained by using a Monte-Carlo computer code. In addition, the experimental results at the same geometry and materials were compared with those calculated.

11

Manufacturing of a graphite calorimeter at Yazd Radiation Processing Center

Ziaie F.

Nukleonika

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2004

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Vol. 49, nr 4

159-162

EN

In this work, a few quasi-adiabatic graphite calorimeters of different dimensions are described. These calorimeters have been manufactured by ourselves and studied for accurate absorbed dose measurements in 10 MeV electron beam. In order to prove the accuracy and reliability of dose measurements with the use of the self designed graphite calorimeters (SDC), an inter comparison study was performed on these calorimeters and RisŘ's graphite calorimeters (SC, standard calorimeter) at different doses by using a Rhodotron accelerator. The comparison shows conclusively SDC of the optimal size, the results agreeing with those obtained with the SC within 1%.