A technique for measuring the spatial heterogeneity of the light yield of a proton radiography scintillator has been developed. It is based on the recording of digital images formed during the ...passage of a proton beam through a scintillator and the approximation of the intensity distribution in the beam cross section by a two-dimensional Gaussian-like function. The results of the spatial calibration of the light yield of a lutetium silicate scintillator obtained using a magneto-optical proton microscope PUMA are presented. It is shown that accounting of the spatial heterogeneity of the scintillator makes it possible to describe the transverse beam intensity at each point of the proton radiographic image with a mean accuracy of about 0.7%. Experimental data on fluctuations in the position of the beam center, its size, and shape in the scintillator plane of PUMA microscope were obtained. The proposed technique eliminates optical artifacts in the radiographic image caused by operation of the optical recording system and artifacts caused by the electron-optical shutter, provided that the signal is proportional to the intensity of the beam. It also eliminates or strongly suppresses optical artifacts in radiographic images due to changes in the efficiency of a charge-coupled digital camera.
A high explosive shock tube of non-ideal gaseous plasma for proton radiography is described. The gas dynamic flow in the shock compressed xenon at initial pressure of 7 bar was investigated in the ...tube. The velocity of the shock wave in xenon and the associated particle velocity were measured by a high-speed rotating mirror streak camera. Experimental time-distance data was used for approximation of the velocities by exponential decay functions. The shock tube is intended for generation of non-ideal plasma of xenon at the pressure of 5-12 kbar, the density of 0.24-0.3 g/cm3 when the initial pressure is about 7 bar.
The article describes possible experiments with explosively driven non-ideal plasma at the proton microscope at the Facility for Antiprotons and Ion Research. It is proposed to employ linear ...explosive tubes for plasma generation and to measure an areal density in shock-compressed plasma of argon and xenon. The proposed experiments will provide valuable information on influence of strong interparticle interactions on thermodynamic properties of strongly coupled plasma. The density measurement will help the researchers to understand the nature of wall and wire precursors arising in the shock tubes.
A method has been developed for calculating the proton beam transmission of static objects with a quasi-uniform areal density from a single proton radiography image under the condition of ...a Gaussian-like transverse beam profile. The calculated images of the transmission are intended to reconstruct the density of the investigated objects. A proton radiography of static targets was performed on an experimental setup with special magnetic optics PUMA with a proton energy of 800 MeV and an intensity of 10
10
particles per image. It is shown that the application of the method makes it possible to reconstruct the proton beam transmission of the object under study with an average relative error of approximately 1–1.2%.
The article reviews the design and physical applications of high‐explosive generators for dense low‐temperature plasma. The PUMA proton microscope with magnetic optics at the Institute for ...Theoretical and Experimental Physics by A.I. Alikhanov of National Research Centre «Kurchatov Institute» (Moscow, Russia) was used to diagnose the plasma. The generators were developed for measurements of the equation of state of non‐ideal plasma, investigation of phase transitions in hydrogen or molecular gases, and studies of the properties of the interior of Giant planets. A proposal was made to repeat the experiments with explosive generators using the proton microscope PRIOR (Proton Microscope for Facility for Anti‐proton and Ion Research) at the GSI Helmholtzzentrum fur Schwerionenforschung (Darmstadt, Germany) and at the designed proton microscope at the Institute for Nuclear Research (Troitsk, Russia).
A radiographic facility for an investigation of fast dynamic processes with areal density of targets up to 5 g/cm2 is under development on the basis of high-current proton linear accelerator at the ...Institute for Nuclear Research (Troitsk, Russia). A virtual model of the proton microscope developed in a software toolkit Geant4 is presented in the article. Fullscale Monte-Carlo numerical simulation of static radiographic experiments at energy of a proton beam 247 MeV was performed. The results of simulation of proton radiography experiments with static model of shock-compressed xenon are presented. The results of visualization of copper and polymethyl methacrylate step wedges static targets also described.
ABSTRACT
The existence of high-energy astrophysical neutrinos has been unambiguously demonstrated, but their sources remain elusive. IceCube reported an association of a 290-TeV neutrino with a ...gamma-ray flare of TXS 0506 + 056, an active galactic nucleus with a compact radio jet pointing to us. Later, radio-bright blazars were shown to be associated with IceCube neutrino events with high statistical significance. These associations remained unconfirmed with the data of independent experiments. Here, we report on the detection of a rare neutrino event with the estimated energy of 224 ± 75 TeV from the direction of TXS 0506 + 056 by the new Baikal Gigaton Volume Detector (Baikal-GVD) in April 2021. This event is the highest energy cascade detected so far by the Baikal-GVD neutrino telescope from a direction below horizon. The result supports previous suggestions that radio blazars in general, and TXS 0506 + 056 in particular, are the sources of high-energy neutrinos, and opens up the cascade channel for the neutrino astronomy.
Orbital adipose tissue Borzenok, S A; Gushchina, M B; Afanasyeva, D S ...
Oftalʼmokhirurgii͡a︡ = Ophthalmosurgery,
07/2016
2
Journal Article
Recenzirano
Odprti dostop
We summarized the results of Russian and foreign researches elucidating embryogenesis, topography and anatomy of different orbital fat pads. It is interesting that adipose tissue from different ...surgical adipose spaces do not stem from the same germ layers. The medial fat pad continued by the central part of orbital adipose tissue between extraocular muscles stems from the neuroectoderm of neural crest, in contrast to the adipose tissue of other depots forming of the mesoderm. Morphological, functional and topographic features of the orbital adipose tissue forming during embryogenesis influence to the further eyeball development. This article focuses on the found correlations between morphological features of the orbital adipose tissue and various eye diseases caused by autoimmune and other factors. The data reviewed in this article confirm the involvement of retroorbital adipose tissue in pathological process not only in Grave's ophthalmopathy, but also in abnormal refraction, glaucoma, hereditary and acquired retinal dystrophies. This article also covers the features of orbital adipose tissue in acquired ptosis of upper eye lid. Nevertheless, due to the lack of studies of the orbital adipose tissue it seems to be impossible to explain all of the found evidences and determine the role of adipose tissue in pathogenesis of eye diseases. The further interdisciplinary investigations of this unique adipose depot are required.
Adipose tissue is widely used in transplantology to fill up volume deficiency as well as the source of cells to treat dysfunctions. Despite the long experience of adipose tissue autotransplantation ...there is still no guarantee of optimal result in late postoperative period. All these are the reasons to search for new techniques, supplementary factors preventing lysis and fibrosis of graft, and for the most appropriate adipose depots. Study of the current literature allows us to consider orbital adipose tissue as a unique fat depot, having the great potential for transplantology.
Currently, the Baikal-GVD Deep Underwater Neutrino Telescope is being successfully deployed in Lake Baikal. It comprises 96 strings with 3456 optical modules. We present the status and plans for ...further deployment of the Baikal-GVD telescope and discuss the issues related to the development of the next-generation neutrino telescope in Lake Baikal.
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