RADIATION-INDUCED PROCESSES IN PYROLITIC GRAPHITE FILMS USED IN THE COMMERCIAL CYCLOTRON BEAM OUTPUT SYSTEM
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Interaction between negatively charged hydrogen ions and 3 microns pyrolytic graphite films was investi-gated. Irradiation with 18 MeV H¯ ions in the dose range of 1500–5000 μAh was carried out in a residual vacuum no worse than 4·10–4 Pa on the Cyclone cyclotron of 18/9. Irradiation cycles had the duration of 100–120 minutes, ion current density ~320 μA·cm-2 and average time between cycles ~22 hours. The identification of γ-emitting radio-nuclides and the determination of their activity were performed using the spectrometer on highly pure germanium: GEM40-83/DSPEC jr 2.0 detection system; energy range 14,5–2911,4 keV; resolution 0,182 keV/channel. Indenta-tion was carried out at room temperature on a PMT-3 instrument using the standard procedure. In the γ-spectra of pyrolytic graphite irradiated with H+ ions, lines of nickel 57Ni, cobalt 55Co, 56Co, 57Co, 58Co, manganese 54Mn, and chromium 51Cr were observed. The dominant radionuclide was 51Cr with a half-life of 27,7 days. These radionuclides are formed as a result of nuclear reactions with protons of stable iron isotopes (56Fe, 57Fe, 58Fe), chromium (52Cr, 53Cr, 54Cr) and nickel (58Ni). Microdefects appear in irradiated pyrolytic graphite films – dark spots ~1–5 μm in size. They are unevenly distributed over the surface – there are areas of their clusters and relatively clean areas. The sizes of the areas of defects accumulations were in the range of 50–200 μm, the density varied from 10 to 150 mm–2. At loads over 10 g around the tangency point of the indenter, long radial cracks were observed, the length of which varied depending on the load from 50 to 150 microns. The number of cracks depended on the side of the film on which the indentation was made. On the concave side from the tangency point of the indenter 4 cracks diverged, and on the convex side – 3. This indicates the recrystallization of the film into the diamond lattice during the irradi-ation process. In the region of compression deformations, crystallization occurs in the (111) direction with a more dense atomic packing, and during tensile deformations, the packing is less dense (100).
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References
Папаш, А.И. Коммерческие циклотроны. Ч. 1 : Коммерческие циклотроны в диапазоне энергий от 10 до 30 МэВ для производства изотопов / А.И. Папаш, Ю.Г. Аленицкий // Физика элементарных частиц и атомного ядра. – 2008. – Т. 39, № 4. – С. 1150–1215.
Temperature annealing of tracks induced by ion irradiation of graphite / J. Liu [et al.] // Nuclear Instruments and Methods in Physics Research B. – 2006. – Vol. 245, № 1. – P. 126–129.
Денисов, Е.А. Взаимодействие графита с атомарным водородом / Е.А. Денисов, Т.А. Компаниец // Журн. техн. физики. – 2001. – Т. 71, № 2. – С. 111–116.
Banhart, F. Irradiation effects in carbon nanostructures / F. Banhart // Reports on Progress in Physics. – 1999. – Vol. 62. – P. 1181–1221.
Захват дейтерия в графит МПГ-8 и углеводородные пленки при облучении дейтериевой плазмой / В.И. Бурлака [и др.] // Вопр. атом. науки и техники. Сер. Термоядерный синтез. – 2010. – № 2. – С. 33–38.
Углеродные структуры и оборот водородного топлива в термоядерных установках / А.А. Сковорода [и др.] // Вопр. атом. науки и техники. Сер. Термоядерный синтез. – 2008. – № 3. – С. 15–34.
Долгоживущие β-излучающие радионуклиды при производстве радиофармпрепаратов на основе 18F / Д.И. Бринкевич [и др.] // Вестн. Полоц. гос. ун-та. Сер. С, Фундам. науки. – 2019. – № 4. – C. 67–76.
Quantification of the activity of tritium produced during the routine synthesis of 18F fluorodeoxyglucose for positron emission tomography / C. Marshall [et al.] // Journal of Radiological Protection. – 2014. – Vol. 34. – P. 435–444.
Переработка облученной воды [18O]H2O в условиях ПЭТ-центра / С.Д. Бринкевич [и др.] // Радиохимия. – 2019. – Т. 61, № 4. – С. 344–350.
Бринкевич, Д.И. Микромеханические свойства эпитаксиальных слоев GaP, легированных редкоземельным элементом диспрозием / Д.И. Бринкевич, Н.В. Вабищевич, В.С. Просолович // Неорганические материалы. – 2012. – Т. 48, № 8. – С. 878–883.
Monte Carlo simulation and radiometric characterization of proton irradiated [18O]H2O for the treatment of the waste streams originated from [18F]FDG synthesis process / R. Remetti [et al.] // Applied Radiation and Isotopes. – 2011. – Vol. 69. – Р. 1046–1051.
Long-lived radionuclides in the production of 18F-labeled radiopharmaceuticals / V.O. Krot [et al.] // 13th Int. Symposium on the Synthesis and Application of Isotopically Labelled Compounds, Prague, Czech Republic, 3–7 June 2018. –Prague, 2018. – P. 43.
Долгоживущие радионуклиды при производстве [18F]фторхолина для ПЭТ-диагностики / П.В. Тылец [и др.] // Изв. НАН Беларуси. Сер. Хим. науки. – 2018. – № 3. – С. 359–368.
Gamma-ray spectrometric characterization of waste activated target components in a PET cyclotron / P. Guarino [et al.] // Cyclotrons and Their Applications – 2007 : Eighteenth International Conference, Giardini Naxos, 01–05.10.2007, Italy. – Giardini Naxos, 2007. – P. 295–297.
Дымонт, В.П. Влияние термического отжига на спектральные свойства электролитически осажденных углеродных пленок / В.П. Дымонт, М.П. Самцов, Е.М. Некрашевич // Журн. техн. физики. – 2000. – Т. 70, № 7. – С. 92–95.
Control of Graphene’s Properties by Reversible Hydrogenation: Evidence for Graphane / D.C. Elias [et al.] // Science. – 2009. – Vol. 323. – P. 610–613.
Proton irradiation energy dependence of defect formation in grapheme / Lee Sanggeun [et al.] // Applied Surface Science. – 2015. – Vol. 344 – P. 52–56.
Ilyin, A.M. Simulation and Study of Bridge–Like Radiation Defects in the Carbon Nano-Structures / A.M. Ilyin, G.W. Beall, I.A. Tsyganov // Journal of Computational and Theoretical Nanoscience. – 2010. – Vol. 7, № 10. – P. 2004–2007.