Персона:
Дабагов, Султан Барасбиевич

Организационные подразделения

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Институт нанотехнологий в электронике, спинтронике и фотонике

Институт ИНТЭЛ занимается научной деятельностью и подготовкой специалистов в области исследования физических принципов, проектирования и разработки технологий создания компонентной базы электроники гражданского и специального назначения, а также построения современных приборов на её основе. Наша основная цель – это создание и развитие научно-образовательного центра мирового уровня в области наноструктурных материалов и устройств электроники, спинтроники, фотоники, а также создание эффективной инновационной среды в области СВЧ-электронной и радиационно-стойкой компонентной базы, источников ТГц излучения, ионно-кластерных технологий материалов.

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Дабагов

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Султан Барасбиевич

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Теперь показываю 1 - 10 из 42

Только метаданные
Application of polycapillary optics to x-ray fluorescence for advanced spectroscopy and microscopy studies
(2020) Guglielmotti, V.; Hampai, D.; Micheli, L.; Mazzuca, C.; Dabagov, S. B.; Дабагов, Султан Барасбиевич
© 2020 SPIE.Advances in x-ray techniques, including x-ray optics, have paved the way to obtain challenging results in several research fields thanks to the improvement in terms of spatial resolution. This is particularly true for x-ray fluorescence (XRF), where the combination of conventional x-ray sources with polycapillary optics has permitted to have high flux and high focused beams. However, XRF spectroscopy applied to archeological samples at a lab scale is mainly dedicated to qualitative studies. At the same time, quantitative analysis still remains a strong hurdle mainly due to important matrix effects that affect the signal related to the chemical components under evaluation. In this respect the adoption of x-ray optics on both the source and the detector represents a way to improve the signal to noise ratio, necessary for quantitative analysis. At LNF XLab Frascati the expertise, gained on x-ray techniques and on polycapillary lenses, has allowed researchers to carry out advanced μXRF studies. RXR (Rainbow X-ray), is the experimental station dedicated to 2D/3D XRF micro-imaging and TXRF analysis, being equipped with 2 detectors of different energy efficiency (covering a full spectrum from 800 eV to 25 keV) and working in confocal mode with the source coupled with a full-lens and both the detectors combined with dedicated half-lenses. This report aims in depicting the RXR potentialities through the results obtained in 2 case studies dedicated to carry out a semi-quantitative analysis of 2 different artifacts (an ancient book, a Buddhist scroll) by μXRF characterization.
Только метаданные
On a crystal assisted positron source by 10 ÷ 50 MeV electrons
(2020) Abdrashitov, S. V.; Kunashenko, Yu. P.; Pivovarov, Yu. L.; Dabagov, S. B.; Дабагов, Султан Барасбиевич
© 2020 IOP Publishing Ltd and Sissa MedialabThe results of recent studies for the positron production in the crystal assisted radiator-converter approach (“hybrid solution”) are brief analysed for 10 ÷ 50 MeV electrons. Computer simulations have been performed for both coherent and incoherent bremsstrahlung in Si and Ge crystal radiators that successfully irradiate the W amorphous converter to release the electron-positron pairs. The positron stopping calculations in a thick convertor allow the optimal converter thickness for the maximum positron yield to be determined, and moreover, the energy spectra for emitted positron beams to be drawn for optimal converter thickness.
Только метаданные
Cherenkov-channeling radiation by relativistic muons in crystals
(2020) Korotchenko, K. B.; Rozhkova, E. I.; Dabagov, S. B.; Дабагов, Султан Барасбиевич
© 2020, The Author(s).In this work we analyse Cherenkov radiation by relativistic muons, positive and negative, channeled in optically transparent diamond and silicon crystals in comparison with ordinary Cherenkov radiation. We have shown that the maxima in the spectral angular distributions for both types of radiation are revealed at the derivative extrema for the media refractive index, while, due to the difference in scattering of positively and negatively charged particles at crystal channeling, the number of Cherenkov photons emitted by channeled positive muons might be over the one for negative muons. We have demonstrated that Cherenkov radiation by quasi free projectiles is described as one limiting approximation of a general expression for Cherenkov radiation by channeled projectiles, which takes into account non-zero derivative of the refractive index. The last may result in essential increase of radiation intensity.
Только метаданные
A 3D imaging textural characterization of pyroclastic products from the 1538 AD Monte Nuovo eruption (Campi Flegrei, Italy)
(2019) Liedl, A.; Buono, G.; Lanzafame, G.; Della, Ventura, G.; Dabagov, S. B.; Дабагов, Султан Барасбиевич
© 2019 Elsevier B.V.The explosive volcanic event of the 1538 AD Monte Nuovo eruption (Volcanic Explosivity Index, VEI = 2)in the Campi Flegrei high-risk caldera (Italy)has a strategic significance in the framework of volcanology and volcanic hazard of caldera-forming magmatic systems. In fact, it represents the last and unique historical eruption of the highly populated Phlegraean restless-caldera, and its precursory and eruptive phenomena are well-known because they were described in detail by contemporaneous eyewitnesses. In this study, a set of samples representative of the complete stratigraphic sequence of the Monte Nuovo eruption was characterized using phase-contrast synchrotron radiation computed microtomography and quantitatively investigated through the development of a new protocol for 3D textural analysis of highly-vesiculated volcanic rocks. Previous studies of products from this eruption are available in the literature, mostly based on 2D imaging techniques, and thus provide a useful data set for comparison. The 3D textural measurements allow us to investigate the subvolcanic processes (mechanisms and timing of magma degassing)that occurred during magma ascent in the conduit for each stage of the eruption and their relationship with the variations in the eruptive style described in the contemporaneous accounts of the eruption. This information is fundamental for the definition of a volcanic eruption scenario for such low-VEI events, often recurrent in the history of the caldera, and is useful both for hazard assessment and emergency planning.
Только метаданные
The laser-based gain monitoring system of the calorimeters in the Muon g-2 experiment at Fermilab
(2019) Anastasi, A.; Basti, A.; Bedeschi, F.; Boiano, A.; Dabagov, S.; Дабагов, Султан Барасбиевич
The Muon g - 2 experiment, E989, is currently taking data at Fermilab with the aim of reducing the experimental error on the muon anomaly by a factor of four and possibly clarifying the current discrepancy with the theoretical prediction. A central component of this four-fold improvement in precision is the laser calibration system of the calorimeters, which has to monitor the gain variations of the photo-sensors with a 0.04% precision on the short-term (similar to 1 ms). This is about one order of magnitude better than what has ever been achieved for the calibration of a particle physics calorimeter. The system is designed to monitor also long-term gain variations, mostly due to temperature effects, with a precision below the per mille level. This article reviews the design, the implementation and the performance of the Muon g - 2 laser calibration system, showing how the experimental requirements have been met.
Только метаданные
Focusing Properties of Bent Micro-Channel Plates in the X-Ray Range
(2019) Mazuritskiy, M. I.; Lerer, A. M.; Marcelli, A.; Hampai, D.; Dabagov, S. B.; Дабагов, Султан Барасбиевич
© 2019, Pleiades Publishing, Ltd.Abstract: Compact and flexible Micro-Channel Plate (MCP) devices are versatile optical systems suitable to condense and shape intense X-ray beams. Studies on propagation of both soft and hard X-ray radiations through these devices are of continuous interests because of increasing demand of synchrotron radiation X‑ray sources, in particular, to enhance the spot stability and to optimize the beam for specific experiments. In this work synchrotron radiation sources as well as a conventional X-ray tube coupled to polycapillary lenses have been used to characterize the transmission and the angular distribution of thin flat or spherically bent MCPs with different curvature radii. It is shown that the radiation beam from both synchrotron radiation and conventional X-ray sources can be efficiently condensed by thin spherically bent MCPs.
Только метаданные
Coherent X-ray Fluorescent Excitation inside MCP Microchannels: Axial Channeling and Wave Propagation
(2021) Mazuritskiy, M. I.; Lerer, A. M.; Marcelli, A.; Dabagov, S. B.; Дабагов, Султан Барасбиевич
© 2021, Pleiades Publishing, Ltd.Abstract: We have experimentally and theoretically characterised silicon-glass Micro-Channel Plate (MCP) devices doped with cobalt atoms. Under anomalous scattering condition near the SiL-edges and CoK-edge we have proved the coherent excitation and the axial propagation of the induced fluorescence radiation inside micro-channels. Chemical modification of the MCP inner surface shows the efficient transmission of hard X-ray secondary radiation at the primary radiation energies of ~100 eV and ~8 keV. Experimental tests for these X-ray waveguides have been performed utilising both synchrotron radiation and conventional X-ray sources. X-ray pattern simulations point out that the propagating radiation has a waveguide modal character, which is described as axial channeling of the secondary fluorescence radiation.
Только метаданные
Beam dynamics corrections to the Run-1 measurement of the muon anomalous magnetic moment at Fermilab
(2021) Albahri, T.; Anastasi, A.; Badgley, K.; Dabagov, S.; Дабагов, Султан Барасбиевич
© 2021 authors.This paper presents the beam dynamics systematic corrections and their uncertainties for the Run-1 dataset of the Fermilab Muon g-2 Experiment. Two corrections to the measured muon precession frequency ωam are associated with well-known effects owing to the use of electrostatic quadrupole (ESQ) vertical focusing in the storage ring. An average vertically oriented motional magnetic field is felt by relativistic muons passing transversely through the radial electric field components created by the ESQ system. The correction depends on the stored momentum distribution and the tunes of the ring, which has relatively weak vertical focusing. Vertical betatron motions imply that the muons do not orbit the ring in a plane exactly orthogonal to the vertical magnetic field direction. A correction is necessary to account for an average pitch angle associated with their trajectories. A third small correction is necessary, because muons that escape the ring during the storage time are slightly biased in initial spin phase compared to the parent distribution. Finally, because two high-voltage resistors in the ESQ network had longer than designed RC time constants, the vertical and horizontal centroids and envelopes of the stored muon beam drifted slightly, but coherently, during each storage ring fill. This led to the discovery of an important phase-acceptance relationship that requires a correction. The sum of the corrections to ωam is 0.50±0.09 ppm; the uncertainty is small compared to the 0.43 ppm statistical precision of ωam.
Только метаданные
Measurement of the Positive Muon Anomalous Magnetic Moment to 0.46 ppm
(2021) Abi, B.; Albahri, T.; Al-Kilani, S.; Dabagov, S.; Дабагов, Султан Барасбиевич
© 2021 authors.We present the first results of the Fermilab National Accelerator Laboratory (FNAL) Muon g-2 Experiment for the positive muon magnetic anomaly aμ(gμ-2)/2. The anomaly is determined from the precision measurements of two angular frequencies. Intensity variation of high-energy positrons from muon decays directly encodes the difference frequency ωa between the spin-precession and cyclotron frequencies for polarized muons in a magnetic storage ring. The storage ring magnetic field is measured using nuclear magnetic resonance probes calibrated in terms of the equivalent proton spin precession frequency ω p ′ in a spherical water sample at 34.7 °C. The ratio ωa/ω p ′, together with known fundamental constants, determines aμ(FNAL)=116 592 040(54)×10-11 (0.46 ppm). The result is 3.3 standard deviations greater than the standard model prediction and is in excellent agreement with the previous Brookhaven National Laboratory (BNL) E821 measurement. After combination with previous measurements of both μ+ and μ-, the new experimental average of aμ(Exp)=116 592 061(41)×10-11 (0.35 ppm) increases the tension between experiment and theory to 4.2 standard deviations.
Только метаданные
Measurement of the anomalous precession frequency of the muon in the Fermilab Muon g-2 Experiment
(2021) Albahri, T.; Anastasi, A.; Anisenkov, A.; Badgley, K.; Dabagov, S.; Дабагов, Султан Барасбиевич
© 2021 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3.The Muon g-2 Experiment at Fermi National Accelerator Laboratory (FNAL) has measured the muon anomalous precession frequency ωam to an uncertainty of 434 parts per billion (ppb), statistical, and 56 ppb, systematic, with data collected in four storage ring configurations during its first physics run in 2018. When combined with a precision measurement of the magnetic field of the experiment's muon storage ring, the precession frequency measurement determines a muon magnetic anomaly of aμ(FNAL)=116 592 040(54)×10-11 (0.46 ppm). This article describes the multiple techniques employed in the reconstruction, analysis, and fitting of the data to measure the precession frequency. It also presents the averaging of the results from the 11 separate determinations of ωam, and the systematic uncertainties on the result.