Nuclear-physical methods of analysis of noble metals and rare-earth elements

A summary of the analysis noble and rare metals by combined methods is presented. The electrodeposition of gold at a carbon film and Rutherford backscattering was used for determination its in ores. The sorbents and particle induced X-ray emission was used for determination rare and noble metals in ores. The minimum detectable concentration for ores was 0.1 mg/g

Use of electron linac for study of fission product and actynide diffusion through glass ceramic matrices

The diffusion of cerium and uranium was investigated in glass ceramic matrices obtained in the gasostat. For activation of isotopes ¹⁴⁰´¹⁴²Се and ²³⁸U the brake radiation from electrons of the linear accelerator was used. The threshold of detectability of elements was reached from 5 to 15 µg/g for a sample of the area 1 cm². The coefficients of diffusion in the grain material and at grain boundaries were measured, and their values for the pressing temperature of 910°С and pressure 100~МPa were 3.5⋅10⁻⁹ cm²/s in the grain and 1.2⋅10⁻⁸ cm²/s at grain boundaries.Методом зняття шарів вивчена дифузія церію й урану в синтезовані за допомогою газостатического пресування склокерамічної матриці. Для активації ізотопів ¹⁴⁰´¹⁴²Се і ²³⁸U використовувалося гальмове випромінювання від електронів лінійного прискорювача. Межа виявлення ізотопів церію й урану становила 10⁻⁵ г/г. Були вимірювані коефіцієнти дифузії в матеріалі зерна і по границях, що при температурі пресування 910°С і тиску 100 МПа склали 3,5⋅10⁻⁹ см²/с у зерні і 1,2⋅10⁻⁸ см²/с по границях зерен.Методом снятия слоев изучена диффузия церия и урана в синтезированные посредством газостатического прессования стеклокерамические матрицы. Для активации изотопов ¹⁴⁰´¹⁴²Се и ²³⁸U использовалось тормозное излучение от электронов линейного ускорителя. Предел обнаружения изотопов церия и урана составил 10⁻⁵ г/г. Были измерены коэффициенты диффузии в материале зерна и по границам, которые при температуре прессования 910°С и давлении 100 МПа составили 3,5⋅10⁻⁹ см²/с в зерне и 1,2⋅10⁻⁸ см²/с по границам зерен

The dynamics of element content in patients with lung cancer during radiotherapy

Determination of the element contents in the biological samples (blood, serum of blood, hair) of patients with the diagnosis of lung cancer III degree is carried out during beam therapy. The method of PIXE excited by protons on the accelerator with energy 3 MeV has been used. During radiotherapy the difference in the element contents in hair of patients has not been detected. Trustworthy reduction of Fe, Cu, Mn, Ca, Sr, Rb etc is marked during treatment. The obtained results can be used as the additional test at carrying out adequate treatment in radiotherapy.Проведено визначення вмiсту мiкроелементiв в бiологiчних зразках (кров, сироватка кровi, волосся) пацiєнтiв з дiагнозом раку легенi III ступеня в процесi променевої терапiї. Використовувався метод характеристичного рентгенiвського випромiнювання, яке збуджувалось протонами прискорювача з енергiєю 3 МеВ. Протягом радiотерапiї вiдмiнностей у вмiстi елементiв у волоссях пацiєнтiв виявлено не було. У процесi лiкування вiрогiдно виявлене зменшення Fe, Cu, Mn, Ca, Sr, Rb i т.д. в кровi i сироватцi кровi. Отриманi результати можуть бути використанi як додатковий тест при проведеннi адекватної терапiї в курсi променевого лiкування.Проведено определение содержания микроэлементов в биологических образцах (кровь, сыворотка крови, волосы) пациентов с диагнозом рака легкого III степени в процессе лучевой терапии. Использован метод характеристического рентгеновского излучения, возбуждаемого протонами на ускорителе с энергией 3 МэВ. В течение радиотерапии отличий в содержании элементов в волосах пациентов обнаружено не было. В процессе лечения достоверно обнаружено уменьшение Fe, Cu, Mn, Ca, Sr, Rb и т.д. в крови и сыворотке крови. Полученные результаты могут быть использованы в качестве дополнительного теста при проведении адекватной терапии в курсе лучевого лечения

Application of gamma activation analysis for research of Cs and I diffusion into a glassceramic matrix

Nuclear reactions ¹³³Cs(γ,n)¹³²Cs, ¹²⁷I(γ,n)¹²⁶I were utilized for research of Cs and I diffusion in glassceramic matrices. The glassceramic matrix was manufactured with the help of hot isostatic pressing at 910°C and pressure 100 MPa. Diffusivities of cesium and iodine in a grain and through interphase boundary at 600°C were equal 10⁻¹¹ and 7.9⋅10⁻⁹ sm²/s, accordingly. The decrease of iodine diffusivity in a grain was observed at 750°C. A method of manufacture of glassceramic matrix for long-lived storage and nuclear-waste disposal ¹²⁹I is proposed.Ядерные реакции ¹³³Cs(γ,n)¹³²Cs, ¹²⁷I(γ,n)¹²⁶I использовались для исследования диффузии Cs и I в стеклокерамической матрице. Стеклокерамическая матрица изготовлена при помощи газостатического прессования при 910°С и давлении 100 МПа. Коэффициенты диффузии цезия и йода в зерне и по границам зерен при 600°С составили 10⁻¹¹ и 7,9⋅10⁻⁹ см²/с, соответственно. Обнаружено уменьшение коэффициента диффузии йода в зерне при 750°С. Предложен способ создания матрицы для захоронения ¹²⁹I.Ядерні реакції ¹³³Cs(γ,n)¹³²Cs, ¹²⁷I(γ,n)¹²⁶I використовувалися для дослідження дифузії Cs та I у склокерамічній матриці. Склокерамічна матриця виготовлена за допомогою газостатичного пресування при 910°С і тиску 100 МПа. Коефіцієнти дифузії цезію і йоду в зерні і по границях зерен при 600° С склали 10⁻¹¹ та 7,9⋅10⁻⁹ см²/с, відповідно. Виявлено зменшення коефіцієнта дифузії йоду в зерні при 750°С. Запропоновано спосіб створення матриці для поховання ¹²⁹I

Li2_2100depl^{100\textrm{depl}}MoO4_4 Scintillating Bolometers for Rare-Event Search Experiments

International audienceWe report on the development of scintillating bolometers based on lithium molybdate crystals containing molybdenum depleted in the double-$\beta$ active isotope $^{100}$Mo (Li$_2$$^{100\textrm{depl}}$MoO$_4$). We used two Li$_2$$^{100\textrm{depl}}$MoO$_4$ cubic samples, 45 mm side and 0.28 kg each, produced following purification and crystallization protocols developed for double-$\beta$ search experiments with $^{100}$Mo-enriched Li$_2$MoO$_4$ crystals. Bolometric Ge detectors were utilized to register scintillation photons emitted by the Li$_2$$^{100\textrm{depl}}$MoO$_4$ crystal scintillators. The measurements were performed in the CROSS cryogenic set-up at the Canfranc underground laboratory (Spain). We observed that the Li$_2$$^{100\textrm{depl}}$MoO$_4$ scintillating bolometers are characterized by excellent spectrometric performance ($\sim$3--6 keV FWHM at 0.24--2.6 MeV $\gamma$'s), moderate scintillation signal ($\sim$0.3--0.6 keV/MeV depending on light collection conditions) and high radiopurity ($^{228}$Th and $^{226}$Ra activities are below a few $\mu$Bq/kg), comparable to the best reported results of low-temperature detectors based on Li$_2$MoO$_4$ with natural or $^{100}$Mo-enriched molybdenum content. Prospects of Li$_2$$^{100\textrm{depl}}$MoO$_4$ bolometers for use in rare-event search experiments are briefly discussed

Li2_2100depl^{100\textrm{depl}}MoO4_4 Scintillating Bolometers for Rare-Event Search Experiments

International audienceWe report on the development of scintillating bolometers based on lithium molybdate crystals containing molybdenum depleted in the double-$\beta$ active isotope $^{100}$Mo (Li$_2$$^{100\textrm{depl}}$MoO$_4$). We used two Li$_2$$^{100\textrm{depl}}$MoO$_4$ cubic samples, 45 mm side and 0.28 kg each, produced following purification and crystallization protocols developed for double-$\beta$ search experiments with $^{100}$Mo-enriched Li$_2$MoO$_4$ crystals. Bolometric Ge detectors were utilized to register scintillation photons emitted by the Li$_2$$^{100\textrm{depl}}$MoO$_4$ crystal scintillators. The measurements were performed in the CROSS cryogenic set-up at the Canfranc underground laboratory (Spain). We observed that the Li$_2$$^{100\textrm{depl}}$MoO$_4$ scintillating bolometers are characterized by excellent spectrometric performance ($\sim$3--6 keV FWHM at 0.24--2.6 MeV $\gamma$'s), moderate scintillation signal ($\sim$0.3--0.6 keV/MeV depending on light collection conditions) and high radiopurity ($^{228}$Th and $^{226}$Ra activities are below a few $\mu$Bq/kg), comparable to the best reported results of low-temperature detectors based on Li$_2$MoO$_4$ with natural or $^{100}$Mo-enriched molybdenum content. Prospects of Li$_2$$^{100\textrm{depl}}$MoO$_4$ bolometers for use in rare-event search experiments are briefly discussed

Aboveground test of an advanced Li2_2MoO4_4 scintillating bolometer to search for neutrinoless double beta decay of 100^{100}Mo

Large lithium molybdate (Li2MoO4) crystal boules were produced by using the low thermal gradient Czochralski growth technique from deeply purified molybdenum. A small sample from one of the boules was preliminary characterized in terms of X-ray-induced and thermally-excited luminescence. A large cylindrical crystalline element (with a size of circle divide 40 x 40 mm) was used to fabricate a scintillating bolometer, which was operated aboveground at similar to 15 mK by using a pulse-tube cryostat housing a high-power dilution refrigerator. The excellent detector performance in terms of energy resolution and alpha background suppression along with preliminary positive indications on the radiopurity of this material show the potentiality of Li2MoO4 scintillating bolometers for low-counting experiment to search for neutrinoless double beta decay of Mo-100. (C) 2015 Elsevier B.V. All rights reserved

The background model of the CUPID-Mo 0νββ0\nu\beta\beta experiment

International audienceCUPID-Mo, located in the Laboratoire Souterrain de Modane (France), was a demonstrator for the next generation $0\nu\beta\beta$ decay experiment, CUPID. It consisted of an array of 20 enriched Li$_{2}$$^{100}$MoO$_4$ bolometers and 20 Ge light detectors and has demonstrated that the technology of scintillating bolometers with particle identification capabilities is mature. Furthermore, CUPID-Mo can inform and validate the background prediction for CUPID. In this paper, we present a detailed model of the CUPID-Mo backgrounds. This model is able to describe well the features of the experimental data and enables studies of the $2\nu\beta\beta$ decay and other processes with high precision. We also measure the radio-purity of the Li$_{2}$$^{100}$MoO$_4$ crystals which are found to be sufficient for the CUPID goals. Finally, we also obtain a background index in the region of interest of 3.7$^{+0.9}_{-0.8}$(stat)$^{+1.5}_{-0.7}$(syst)$\times10^{-3}$counts/$\Delta$E$_{FWHM}$/mol$_{iso}$/yr, the lowest in a bolometric $0\nu\beta\beta$ decay experiment

Final results on the 0νββ0\nu\beta\beta decay half-life limit of 100^{100}Mo from the CUPID-Mo experiment

The CUPID-Mo experiment to search for 0$\nu\beta\beta$ decay in $^{100}$Mo has been recently completed after about 1.5 years of operation at Laboratoire Souterrain de Modane (France). It served as a demonstrator for CUPID, a next generation 0$\nu\beta\beta$ decay experiment. CUPID-Mo was comprised of 20 enriched Li$_2$$^{100}$MoO$_4$ scintillating calorimeters, each with a mass of $\sim$ 0.2 kg, operated at $\sim$20 mK. We present here the final analysis with the full exposure of CUPID-Mo ($^{100}$Mo exposure of 1.47 kg$\times$yr) used to search for lepton number violation via 0$\nu\beta\beta$ decay. We report on various analysis improvements since the previous result on a subset of data, reprocessing all data with these new techniques. We observe zero events in the region of interest and set a new limit on the $^{100}$Mo 0$\nu\beta\beta$ decay half-life of $T^{0\nu}_{1/2} > 1.8 \times 10^{24}$ year (stat.+syst.) at 90% C.I. Under the light Majorana neutrino exchange mechanism this corresponds to an effective Majorana neutrino mass of \left < (0.28--$0.49)$ eV, dependent upon the nuclear matrix element utilized

New measurement of double beta decays of 100^{100}Mo to excited states of 100^{100}Ru with the CUPID-Mo experiment

The CUPID-Mo experiment, located at Laboratoire Souterrain de Modane (France), was a demonstrator experiment for CUPID. It consisted of an array of 20 Li$_2^{100}$MoO$_4$ (LMO) calorimeters each equipped with a Ge light detector (LD) for particle identification. In this work, we present the result of a search for two-neutrino and neutrinoless double beta decays of $^{100}$Mo to the first 0$^+$ and $2^+$ excited states of $^{100}$Ru using the full CUPID-Mo exposure (2.71 kg$\times$yr of LMO). We measure the half-life of $2\nu\beta\beta$ decay to the $0^{+}_1$ state as $T_{1/2}^{2\nu \rightarrow 0_1^+}=7.5\pm 0.8 \ \text{(stat.)} \ ^{+ 0.4}_{-0.3} \ \text{(syst.)} )\times 10^{20} \ \mathrm{yr}$. The bolometric technique enables measurement of the electron energies as well as the gamma rays from nuclear de-excitation and this allows us to set new limits on the two-neutrino decay to the $2_1^+$ state of T^{2\nu \rightarrow 2_1^+}_{1/2}>4.4\times 10^{21} \ \mathrm{yr} \ \text{(90 % c.i.)} and on the neutrinoless modes of T_{1/2}^{0\nu\rightarrow 2_1^+}>2.1\times10^{23} \ \mathrm{yr}\ \text{(90 % c.i.)}, T_{1/2}^{0\nu\rightarrow 0_1^+}>1.2\times10^{23} \ \mathrm{yr}\ \text{(90 % c.i.)}. Information on the electrons spectral shape is obtained which allows us to make the first comparison of the single state (SSD) and higher state (HSD) $2\nu\beta\beta$ decay models for the $0_1^+$ excited state of $^{100}$Ru