Transient Absorption Phenomena in Synthetic HPHT and CVD Diamonds for a Fast Timing in Nuclear Instrumentation

In this study, we investigate  transient phenomena in synthetic diamonds  obtained by High Pressure High Temperature and Chemical Vapor Deposition methods. Study was aimed at searching for inorganic crystalline media combining ionizing radiation detecting properties and non-linear absorption of ultra-short laser pulses. The nonlinear pump-and-probe optical absorption technique with of 140 fs laser pulses was used to study the effects

Lanthanoid-doped quaternary garnets as phosphors for high brightness cathodoluminescence-based light sources

Gadolinium-yttrium- aluminum-gallium garnets (GYAGG) doped and codoped with Eu, Tb, and Ce were manufactured as ceramics to develop long-wavelength phosphors for high-brightness white light sources based on cathodoluminescence (CL). The CL light yield (LY) of Tb-doped ceramics at high-intensity electron beam excitation is shown to be more than twice as high as that of the conventional phosphor YAG:Ce, whereas codoping with Eu to redshift the chromaticity results in reducing the LY approximately to the level of YAG:Ce. The LY might be substantially improved by using a mix of Tb- and Eu-doped GYGAG powders instead of a single codoped GYGAG to produce ceramic phosphor. The high LY is explained by favorable contribution of Gd sublattice in excitation transfer to activator ions. Chromaticity of phosphors GYGAG:Tb, Eu can be tuned in a wide range by varying the ratio of Tb to Eu concentration. They are radiation resistant and stabile in the temperature range from 300 to 450 K. © 2022 The Author(s)Ministry of Education and Science of the Russian Federation, Minobrnauka: 075-11-2021-070, 075-15-2021-1353, FEUZ-2020-0060This work was supported by the Ministry of Science and Higher Education of the Russian Federation (FEUZ-2020-0060, No. 075-15-2021-1353 & 075-11-2021-070)

Towards effective indirect radioisotope energy converters with bright and radiation hard scintillators of (Gd,Y)3Al2Ga3O12 family

Ceramics of quaternary garnets (Gd,Y)3Al2Ga3O12 doped with Ce, Tb have been fabricated and evaluated as prospective materials for indirect energy converters of α-and β-voltaic. Samples were characterized at excitation with an X-ray source and an intense 150 keV electron beam and showed good temperature stability of their emission and tolerance to irradiation. The role of X-rays accompanied the α-particle emitting in the increase of the conversion efficiency is clarified. The garnet-type structure of the matrix in the developed materials allows the production of quality crystalline mass with a light yield exceeding that of the commonly used YAG: Ce scintillator by a factor of two times. © 2022 Korean Nuclear SocietyMinistry of Education and Science of the Russian Federation, Minobrnauka: 075-15-2021-1353, FEUZ-2020-0060; Ministerstwo Edukacji i Nauki, MNiSW: 075-11-2021-070; Ministry of Science and Higher Education of the Russian FederationAuthors with affiliations b, d, e and f acknowledge support from Russian Ministry of Science and Education grant No. 075-15-2021-1353 . The scientific equipment provided by shared research facilities “Scientific Research Analytical Center of National Research Center “Kurchatov Institute” – IREA” was used, with financial support of Russian Federation, represented by the Ministry of Science and Higher Education, agreement No. 075-11-2021-070 dated August 19, 2021. The work was partially supported by the Ministry of Science and Higher Education of the Russian Federation (through the basic part of the government mandate, project No. FEUZ-2020-0060 ) (authors with affiliation “c”).Authors with affiliations b, d, e and f acknowledge support from Russian Ministry of Science and Education grant No. 075-15-2021-1353. The scientific equipment provided by shared research facilities “Scientific Research Analytical Center of National Research Center “Kurchatov Institute” – IREA” was used, with financial support of Russian Federation, represented by the Ministry of Science and Higher Education, agreement No. 075-11-2021-070 dated August 19, 2021. The work was partially supported by the Ministry of Science and Higher Education of the Russian Federation (through the basic part of the government mandate, project No. FEUZ-2020-0060) (authors with affiliation “c”)

The Saturation of the Response to an Electron Beam of Ce- and Tb-Doped GYAGG Phosphors for Indirect β-Voltaics

GYAGG:Tb (Ce) scintillators have been confirmed to be promising sources of light emission when excited by an intense 150 keV electron beam. The saturation of the scintillation yield under such excitation conditions has been studied. To explain the results obtained, a model that considers the Auger quenching mechanism was used. The Ce-doped material did not show saturation, whereas a moderate 30% drop of the yield was measured in the Tb-doped sample at the highest excitation beam intensity ~1 A/cm2. This put forward a way to exploit the Tb-doped scintillator for indirect β-voltaic batteries. © 2023 by the authors.National Research Council Canada, NRC; Ministry of Education and Science of the Russian Federation, Minobrnauka: 075-15-2021-1353, FEUZ 2023-0013The authors at NRC “Kurchatov Institute” and Moscow State University acknowledge support from the Russian Ministry of Science and Education, Agreement No. 075-15-2021-1353. Analytical studies have been carried out using the scientific equipment of NRC Kurchatov Institute IREA. The research at Ural Federal University was partially supported by the Ministry of Science and Higher Education of the Russian Federation (Project FEUZ 2023-0013)

Application of dye leak test for gastrointestinal tract tightness control in bariatric surgery

Проблема ожирения широко распространена как в Республике Беларусь, так и в мировом масштабе. Так по данным ВОЗ ожирением страдают 640 млн человек в мире. В Республике Беларусь в 2015–2016 г. распространенность ожирения среди взрослого населения составляла 24,5 % . Морбидное ожирение при ИМТ >40 кг/м2, или >35 кг/м2 при наличии сопутствующей патологии, часто оказывается рефрактерным к консервативным методам лечения и наиболее эффективным способом устойчивого снижения массы тела пациентов является именно хирургическое вмешательство. Среди выполняемых бариатрических операций преобладают вмешательства, предусматривающие резекцию или шунтирование желудка. Так в мире доля гастрошунтирования на петле по Ру составляет 41,9 %, рукавной резекция желудка – 32,6 %, а на долю минигастрошунтирования приходится 5,0 %. Одним из наиболее частых осложнений после перечисленных бариатрических вмешательств является несостоятельность линии швов желудка или анастомозов. После рукавной резекции желудка частота этого осложнения достигает 3,9 %, а после гастрошунтирования на петле по Ру – до 8 %. The problem of obesity is widespread both in the Republic of Belarus and on a global scale. So, according to the WHO, 640 million people in the world suffer from obesity [6]. In the Republic of Belarus in 2015–2016.rasprostranennost' ozhireniya sredi vzroslogo naseleniya sostavlyala 24,5 %. Morbidnoye ozhireniye pri IMT >40 kg/m 2 , ili >35 kg/m 2 pri nalichii soputstvuyushchey patologii, chasto okazyvayetsya refrakternym k konservativnym the prevalence of obesity among the adult population was 24.5 %. Morbid obesity with a BMI >40 kg/m 2 , or >35 kg/m 2 in the presence of concomitant pathology, is often weight loss in patients is precisely surgical intervention. Among the performed bariatric operations, interventions involving gastric resection or bypass surgery prevail. Thus, in the world, the share of gastric bypass surgery on a Roux-type loop is 41.9 %, sleeve gastrectomy is 32.6 %, and the share of mini-gastric bypass is 5.0 %. One of the most common complications after the listed bariatric procedures is the failure of the gastric suture line or anastomoses. After gastric sleeve gastrectomy, the incidence of this complication reaches 3.9 %, and after Roux-en-Y loop gastric bypass surgery – up to 8 %

Picosecond transient absorption rise time for ultrafast tagging of the interaction of ionizing radiation with scintillating crystals in high energy physics experiments

Here we report the first results of a search of a signature for picosecond time stamps of the interaction between ionizing particles and transparent crystalline media. The induced absorption with sub-picosecond rise time observed in a cerium fluoride scintillation single crystal under UV excitation is directly associated with the ionization of Ce(3+) atoms in CeF(3) crystals, and the very fast occurrence thereof can be used to generate picosecond-precise time stamps corresponding to the interaction of ionizing particles with the crystal in high energy physics experiments

Optical transmission damage of undoped and Ce doped Y3Al5O12Y_3Al_5O_{12} scintillation crystals under 24 GeV protons high fluence

This report presents results on the optical transmission damage of undoped and Ce doped $Y_3Al_5O_{12}$ scintillation crystals under high fluence of 24 GeV protons. We observed that, similarly to other middle heavy scintillators, it possesses the unique radiation hardness at fluence values as high as $5×10^{14} p/cm^2$ and it is thus promising for the application in the detectors at High Luminosity LHC. The crystalline structure of the garnet scintillator allows to control and further optimize its scintillation parameters, such as scintillation decay time and emission wavelength, and shows a limited set of the radioisotopes after the irradiation with protons

Comparison of damage effects in plastic scintillators due to irradiation with γ-rays, 190 MeV and 24 GeV protons

Plastic scintillation materials play a crucial role in the construction of large area detectors in high energy physics experiments. Future detector concepts for HEP experiments, particularly at collider facilities, will require an unique combination of the material features and of affordable price. Mandatory is a minimal level of radiation damage due to the electromagnetic part of ionizing radiation and energetic hadrons as well: tolerable deterioration of the optical transmission, negligible impact on the scintillation mechanism and small contribution of radio-luminescence due to secondary reaction products in the detector material. A systematic study of the radiation hardness of inorganic optical and scintillation materials has been performed by us since several years. It resulted in the understanding of the damage effects in particular in self activated, Ce3+-doped and cross-luminescent crystalline materials. Here we report on first results for the industrially produced plastic scintillation material EJ260 (ELJEN). This plastic is a bright, fast and green light emitting scintillator with properties similar to other materials such as BC428 and NE103, respectively. Samples of a thickness of 1.25 cm were tested before and after irradiation with γ-quanta (1.2 MeV, Giessen) and protons of 190 MeV (KVI, Groningen) and 24 GeV (CERN, PS), respectively. No damage of the material properties was observed after irradiation with γ-quanta up to an absorbed dose of 1 kGy consistent with similar studies. However, the exposure to 190 MeV protons with a fluence of 5×1013p/cm2 showed a large reduction of the optical transmission and a slowing down of the scintillation kinetics. In this study we also focused on the impact of high energetic protons. We obtained evidence that light fragments of the (p,12C) reactions play a significant role in the damage of the matrix and the luminescent organic dye centers