bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study of the SiPM double component recovery time
Authors: Bychkova Oksana V , Ilyin Andrey L , Kayumov Fred F , Parygin Pavel P , Philippov Dmitry E , Popova Elena V , Stifutkin Alexey A , Vinogradov Sergey L 
Published: November 2019

Abstract
The recovery time of the Hamamatsu SiPM linear assembly was measured. The assembly contains eight SiPMs of 2.8mm active area diameter; pixel size is 15xl5mkm2. The assembly is used for Phase1 upgrade in hadron calorimeter of the CMS experiment. Recovering process is found to depend on the number of the pixels fired and varied from 7 ±1 ns to 23 ± 3 ns for 50 Ohm readout impedance.
Application of the multichannel front-end chip for SiPM-based gamma detector
Authors: Chergui Ahmed C , Bychkova Oksana V , Popova Elena V , Stifutkin Alexey A 
Published: November 2019

Abstract
A prototype of a multichannel application specific integrated circuit(ASIC)analog front-end chip was recently developed at the Department of Microelectronics in MEPhI for SiPM-based applications[1]. The chip designed as an analog front-end for the detectors using scintillation crystals NaI(Tl) or CsI(Tl) coupled with a SiPM photosensor.The chip can be used to build multichannel systems in such fields as nuclear science, medical imaging and homeland security.
Machine learning approach to pulse shape discrimination in liquid noble gas detectors
Authors: Grobov A 
Published: November 2019

Abstract
Study of the event classification in liquid noble gas detectors is presented. The discrimination between different events usually done by prompt light fraction. To tackle this task we adopt the neural net classifier and use pulse shape as an input feature. The main difficulty comes from low-energy events that are difficult to separate. This is important because these events provide a background for dark matter searches. We find that neural networks are suitable for this task.
The measurement of liquid scintillator nonlinear response and intrinsic energy resolution
Authors: Formozov A 
Published: November 2019

Abstract
For Jiangmen Underground Neutrino Observatory the requirements < 1 % energy scale uncertainty and 3 % at 1 MeV energy resolution are crucial in order to determine neutrino mass hierarchy. In this study, we focus on non-linearity due to ionization quenching and intrinsic energy resolution of the liquid scintillator. To measure them a small-scale laboratory setup was developed and the measurement of Birk’s quenching constant kB = 0.0196 ± 0.0019 (stat) ± 0.0030 (syst) cm/MeV was provided. With the assumption of negligible light collection term, intrinsic energy resolution term was determined: vint
(50keV) ≈ 0.02 ± 0.005. This value is comparable with the statistical term of JUNO, therefore the effect could significantly contribute into the total energy resolution at this energy. Further studies should be directed toward accurate estimation of light collection effects.
Calibration of the ALICE PHOS calorimeter
Authors: Blau Dmitry 
Published: November 2019

Abstract
The procedure for the energy calibration of the high granularity electromagnetic calorimeter PHOS of the ALICE experiment is presented. The methods used to perform the relative gain calibration, to estimate the geometrical alignment and the corresponding correction of the absolute energy scale, to evaluate the non-linearity correction coefficients and finally, to calculate the time-dependent calibration corrections, are discussed and illustrated by the PHOS performance in proton-proton (pp) collisions at

s

=
13

TeV

. After applying all corrections, the widths of π0 and η meson peaks at p
T > 1.7 GeV/c σ
π
0 = 4.51 ± 0.03 MeV/c2 and ση
= 15.3 ± 1.0 MeV/c2, respectively, were achieved.
The Dark Matter search at KamLAND
Authors: Kozlov A. , Chernyak D. , Takemoto Y. , Fushimi K. , Imagawa K. , Yasuda K. , Ejiri H. , Hazama R. , Ikeda H. , Inoue K. , Yoshida S. , Etezov R. A. , Gavrilyuk Yu. M. , Kazalov V. V. , Kuzminov V. V. , Panasenko S. I. 
Published: November 2019

AbstractRecent data from the DAMA/LIBRA phase-2 confirmed detection of a signal with independent Dark Matter (DM) annual modulation signature at a 12.9σCL. Our attempts to verify the DAMA/LIBRA DM observation claim led to construction of underground clean rooms at the KamLAND site and specialized laboratory for production of NaI(Tl) detectors. Current status of these facilities, methods used to grow ultra-low background NaI(Tl) crystals, and radio-purity of the latest NaI(Tl) DM detector prototype are discussed.
Characterization of a scintillator tile equipped with SiPMs for future cosmic-ray space experiments
Authors: Di Venere L , De La Torre Luque P , Gargano F , Giordano F , Fusco P , Loparco F , Loporchio S , Mazziotta M N , Serini D 
Published: November 2019

Abstract
Current gamma-ray and cosmic-ray satellite experiments employ plastic scintillators to discriminate charged and neutral particles and to identify nuclei. Scintillators are commonly read out using the classical photomultiplier tubes (PMTs). Recent measurements and R& D projects are demonstrating that Silicon Photomultipliers (SiPMs) are suitable for the detection of fast light signals with resolution up to the single photoelectron, with a lower power consumption. For these reasons, next generation missions are planning to replace PMTs with SiPMs. We tested a prototype plastic scintillator tile, equipped with a set of SiPMs and studied its response to a beam of electrons and pions at CERN. We used Near Ultraviolet (NUV) SiPMs of 1x1 mm2 and 4x4 mm2 area, placed along the edges of the tile. The tile was irradiated in different positions in order to study the dependence of the collected light on the impact point of the beam particles. We also varied the energy of the beam in order to study how this parameter affects the amount of collected light.
A four-layer gaseous detector allowing to measure the energy of charged particles
Authors: Potashev S , Burmistrov Yu , Zuyev S , Karaevsky S , Konobeevski E , Razin V , Afonin A 
Published: November 2019

Abstract
A four-layer gas detector for electrons and other charged particles is developed. A charged particle passing through a thin window produces ionization in four consecutive gas gaps separated by absorbers. The gas gain about of 104 allows one to determine four signal amplitudes under the control of any combination of these signals. Simultaneous measurement of the ionization losses of the particle in the successive layers of the detector makes it possible to determine the energy of the passing particle.
The principles of neutrino source creation on the base of lithium. The variants of realization (review)
Authors: Lyashuk V I , Lutostansky Yu S 
Published: November 2019

Abstract
It is discussed the conception of antineutrino-electron-source-creation on the base of 7Li isotope and the principal requirements for realization including the possible schemes isotope purity, perspective substances, efficiency. The source can operate in the static and dynamic regimes, in the tandem scheme of the accelerator plus lithium blanket. It was considered the advantages ensured by lithium antineutrino source for neutrino experiments.
Distributions of the charged particles in the electromagnetic showers initiated by 5-1000 GeV electrons in Fe, W and Pb
Authors: Denisov S P , Goryachev V N 
Published: November 2019

Abstract
The results of calculations of the charged particles multiplicity, energy, radial and time distributions in the electromagnetic showers initiated by electrons with energies from 5 to 1000 GeV in Fe, W and Pb are presented. It is shown that the multiplicity distributions are well fitted by the inverse sum of two exponents in a wide range of energy and lead depth. The shapes of energy and radial distributions at the shower maximum weakly depend on the electron energy. Radial distributions for all materials studied are similar if radius is expressed in g/cm2. The time spread of the charged particles at the shower maximum turned out to be in the picosecond range.
The adaptive-modular technique for pre-project simulation the transportation channels of the relativistic charged-particle beams
Authors: Averyanov G P , Budkin V A , Dmitrieva V V 
Published: November 2019

Abstract
Considered the numerical simulation technique which providing optimum beam parameters at the transport channel output of electron accelerator. The KATRAN channels design environment used for this purpose has a modular structure includes the basic beam focusing blocks. This allows enabling create and configure the optical system of the accelerator fast and efficiently if a given topology of the transport channel.
Investigation of muon bundles generated by UHECR by means of the new coordinate-tracking detector
Authors: Zadeba E A , Borisov A A , Fakhrutdinov R M , Ivanov S S , Kokoulin R P , Kompaniets K G , Kozhin A S , Petrukhin A A , Vorobyev V S , Yashin I I 
Published: November 2019

Abstract
The new coordinate-tracking detector based on drift chambers (CTUDC) is created in MEPhI. The detector represents two planes with total area of 30 m2 placed on the opposite sides of Cherenkov water detector of 2000 m3 volume. Each plane consists of 8 large multiwire drift chambers (4000x508x112 mm3). The key advantages of these chambers are a large effective area (1.85 m2) and a good coordinate and angular resolution with a small number of measuring channels. From the beginning of 2017, CTUDC operates as a part of the experimental complex NEVOD. The detector is designed for measuring of high density muon bundles (up to 10 particles per m2) at zenith angles in the range from 30° to 90°. The results of the CTUDC operation during the last year are given, the first distributions of the events in zenith angle, muon bundle multiplicity and density obtained from the detector data are discussed.
Project on searching for neutron-antineutron oscillation at the WWR-M reactor
Authors: Fomin A , Serebrov A , Chaikovskii M , Zherebtsov O , Murashkin A , Golubeva E. 
Published: November 2019

Abstract
Supersource of ultracold neutrons on the basis of superfluid helium is under construction in PNPI NRC KI. It must provide UCN density 2-3 orders of magnitude higher than existing sources. For the new source we propose an experiment on search for neutron–antineutron oscillations based on the storage of ultracold neutrons in a material trap. The sensitivity of the experiment mostly depends on the trap size and the amount of UCN in it. The geometric configuration of the experimental setup was developed based on the MC simulations of neutrons trajectories into the trap. To calculate detector efficiency the GEANT4 model of the detector was created.
New method of high-energy gamma ray direction reconstruction in multilayered converters
Authors: Kheymits M D , Galper A M , Arkhangelskaya I V , Arkhangelskiy A I , Bakaldin A V , Gusakov Yu V , Dalkarov O D , Djivelikyan E A , Egorov A E , Leonov A A , Naumov P Yu , Pappe N Yu , Runtso M F , Stogkov Yu I , Suchkov S I , Topchiev N P , Yurkin Yu T , Zverev V G 
Published: November 2019

Abstract
A new method of high-energy gamma ray incident direction reconstruction is developed for gamma-ray detectors with multilayered converters. The method uses data from converter and, if available, from position-sensitive calorimeter to reconstruct an electromagnetic cascade axis and to determine the incident direction of a primary gamma. For the first time to find point of intersection of gamma direction line with convertor plane, median of energy deposit in sensitive plane of convertor is used. Applied, for example, to the GAMMA-400 space-based gamma-ray telescope this method allowed to achieve the angular resolution ∼0.01° at gamma-ray energy of 100 GeV, being much better than accuracy of the past and present space- and ground-based experiments. In the algorithm presented, a balance between the angular resolution and the effective area can be found to meet a scientific goal of an experiment.
Status of the Russian-Italian experiment NEVOD-EAS
Authors: Chiavassa A , Shulzhenko I A 
Published: November 2019

Abstract
The NEVOD-EAS air shower array is currently under construction in MEPhI, within the Russian-Italian NEVOD-DECOR partnership. The goal of the array is to provide an independent measurement of the size, of the core location and of the arrival direction of the extensive air showers (EAS) detected with the other facilities of the Experimental complex NEVOD. These measurements will provide a calibration of a novel perspective technique developed in the Experimental complex NEVOD for studying inclined muon bundles – the method of local muon density spectra. The array will also extend the opportunities of the Experimental complex NEVOD in carrying out multi-component studies of extensive air showers. The present status of the NEVOD-EAS air-shower array is described and the future perspectives are discussed.
Overview of Hypernuclei Reconstruction at NICA/MPD
Authors: Ilieva M , Zinchenko A , Kolesnikov V 
Published: November 2019

Abstract
The study of the formation of a dense and hot baryonic matter is the main goal of exploration for the NICA/MPD project. Strangeness production in nuclear collisions is a key part of the MPD project physics program and is an important tool for studying the QCD phase diagram. An overview of the relevant characteristics for hypernuclei reconstruction in the NICA energy range with the simulated MPD detector are presented. Focus is put on invariant mass distributions, reconstruction efficiency and expected yields.
Electric arc plasmatorch of a two-chamber scheme with reverse polarity of electrodes connection
Authors: Batomunkuev D Y , Vashenko S P 
Published: November 2019

Abstract
The work is a study of the operating parameters of the plasma torch of a two-chamber scheme with reverse polarity of connection the electrodes. Classical erosion levels of 1.81×10−6 g·Cl−1 and 2.675×10−7 g·Cl−1 for the cathode and anode, respectively, were obtained. Also, on the reverse polarity of the inclusion, the voltage is obtained by 31.8% higher compared to the voltage with the direct polarity of connection.
On the influence of a cathode shape on the parameters of current pulses of runaway electron beams in a gas discharge when applying voltage pulses with a rise time of 200 ns
Authors: Beloplotov D V , Tarasenko V F 
Published: November 2019

Abstract
The influence of the shape of a cathode on the duration and amplitude of a supershort avalanches electron beam (SAEB) current pulses was experimentally studied. Three cathodes were used in experiments: tube, needle, and ball. Voltage pulses with a rise time of 200 ns were applied across an 8.5 mm gap filled with air and nitrogen at various pressures (12.5–100 kPa). It was found that at an air pressure of 12.5 kPa and a rise time of voltage pulses 200 ns, the largest amplitudes of SAEB current pulses (90 mA) were observed with the tubular cathode. The SAEB current pulse duration was τ0.5 ~ 130 ps. Two pulses with different duration, amplitude and energy of electrons were observed with the needle cathode at same pressure. When using the ball cathode, the duration and amplitude of the beam current pulses were τ0.5 ~ 250 ps and ~ 4 mA, respectively.
Delay in plasma generation on the surface of coper and duralumin conductors coated with dielectrics
Authors: Datsko I M , Labetskaya N A , Rybka D V , Vankevich V A , Shugurov V V 
Published: November 2019

Abstract
The skin explosion was investigated for homogeneous and double-layer cylindrical copper and duralumin conductors coated with zirconium dioxide. The MIG generator used in the experiment produced a current of amplitude up to 2.5 MA and rise time 100 ns. To detect the plasma generated on the surface of a conductor due to its electrical explosion, the light emitted by the plasma was imaged using a four-frame optical camera with a frame exposure time of 3 ns. In addition, vacuum x–ray diodes were used to detect the instant at which the temperature of the surface plasma, assumed to be a blackbody, became greater than 1 eV. The internal structure and density of the surface plasma were examined based on its transmission images. The images were taken by exposing the plasma to the x-radiation with hν > 1 keV generated by an X-pinch for 2–3 ns. The QUINTA facility was used to carry out plasma-assisted deposition of multilayer coatings composed of alternating 0.8-μm-thick zirconium dioxide layers and (more durable) 0.2-μm-thick zirconium layers. The total number of layers in a coating could be up to sixteen. At magnetic fields lower than 300 T, the onset of plasma generation on the dielectric-coated load part occurred with a delay of up to 70 ns relative to that on a bare copper or duralumin conductor. Increasing the field to 350–400 T decreased the delay in plasma generation to about 30 ns.
Measurement of plasma parameters in an electron source with a plasma cathode based on a low-pressure arc discharge
Authors: Doroshkevich S Yu , Vorobyov M S , Kovalsky S S , Lopatin I V , Koval N N , Sulakshin S A 
Published: November 2019

Abstract
In the electron source with a grid plasma cathode based on a low-pressure arc discharge, the parameters of the emission plasma were investigated depending on the different conditions of its generation (type of gas, operating pressure, discharge current amplitude, resistance in the hollow anode circuit of a plasma emitter). For this purpose, a single cylindrical Langmuir probe was used. To measure the current-voltage characteristics of the probe, taking into account the features of the functioning of the electron source (galvanic isolation from high accelerating voltage, the use of high-voltage cables with high parasitic parameters, etc.), an automated measurement circuit was used, allowing for a relatively short time to collect high statistics of experimental data (depending on the frequency the impulses of the discharge current and their total number). To eliminate the influence of the parasitic parameters of the circuit, the measurement circuit was located in the maximum proximity to the generation space of the emission plasma (in a vacuum chamber), which significantly increased the accuracy of the experimental data obtained.
A limit value of the volume discharge ignition frequency in dense gases
Authors: Kozlov B A 
Published: November 2019

Abstract
There is deduced analytical expression for maximum value of the volume discharge ignition frequency in dense gases. That expression indicates the way for achieve maximal values of pulse repetition rates in CO2-lasers at atmospheric and super-atmospheric pressures. The increasing of pulse repetition rates is connected with sectioning of main discharge gap and excitation of volume discharge in each section from separate pulse pumping generator. This work is devoted to describing of constructions and main characteristics of some types compact pulse generators with amplitude of voltage pulses up to 200 kV, rise-times about 10 nanoseconds and pulse energy per pulse up to 20 J. For reduction of rise-time of high-voltage pulses were used spark-discharge two electrodes commutators (sharpeners) at working pressures up to 100 atm.
Study of ionization waves in a pulse discharge in argon
Authors: Kurbanismailov V S , Ragimkhanov G B , Tershonok D V , Khalikova Z R 
Published: November 2019

Abstract
In the article we present the results of the investigation of the initial stage of nanosecond discharge formation in inhomogeneous pre-ionized argon of atmospheric pressure. The peculiarities of the cathode directed ionization wave development between two flat electrodes in argon of atmospheric pressure are presented.
Study of ionization waves in a pulse discharge in helium
Authors: Kurbanismailov V S , Omarov O A , Ragimkhanov G B , Tershonok D V 
Published: November 2019

Abstract
The paper presents the results of experimental and numerical studies of the space-time dynamics of the formation of a discharge in helium under conditions of preliminary ionization of the gas. The effect of local field amplification regions on the discharge development is studied.
Study of the ion plasma flow generated by a high-current vacuum arc
Authors: Morozov P A , Punanov I F , Emlin R V , Muziukin I L , Chaikovsky S A , Uimanov I V , Shmelev D L , Zemskov Yu A , Mikhailov P S 
Published: November 2019

Abstract
The vacuum arc discharge is intensively explored for a long time. It acts as a source of multiply charged plasma. The results of the special type plasma gun (5–10 kA, 12 μs) ion flow study with high temporal resolution and the electrode erosion dependences on the amplitude of the current pulse are presented in the research. The ion flow intensity had good reproducibility from series to series, while the values of total mass erosion differ significantly for different series of experiments under the same conditions. The ion erosion was measured to be significantly higher than that for arc sources with currents up to 1 kA.
On the nature of charged particle flow of vacuum arc
Authors: Muzyukin I L , Mikhailov P S 
Published: November 2019

Abstract
Time resolving investigations of charged particles flow from the cathode region of the vacuum arc reveal that the basis of charged particles flow is short-term burst. These bursts can form sequences, groups with a relatively smooth waveform and superbursts. The Fourier analysis showed that ion flow has a brown-like frequency law. This fact can serve as evidence of the fractal nature of the cathode spot. However, the detailed analysis of ionsand accelerated electron signals revealed that the fractal nature of charged particle signal can reflect the fractal nature of plasma turbulences in discharge plasma. Also, the strong correlation between intensive charged particle flow appearance and arc discharge parameter instabilities was revealed. Thus, the plasma instabilities can be considered as the cause of ion and electron flow acceleration in the vacuum arc.
The space charge formed by the runaway electron beam
Authors: Oreshkin E V 
Published: November 2019

Abstract
For discharges in atmospheric pressure air, a numerical simulation of the process of formation of a runaway electron beam from the emission zone at the cathode was performed. The model is based on the numerical solution of the equations of motion of electrons injected from the surface of the emission zone and secondary electrons that appeared during gas ionization. It is shown that when a beam of runaway electrons passes through, a space charge is formed, which determines the electric field in the interelectrode gap.
Measuring the expansion velocity of plasma formed during electrical breakdown along an exploding al foil in a medium of desorbed gases
Authors: Rousskikh A G , Zhigalin A S , Oreshkin V I , Baksht R B 
Published: November 2019

Abstract
This paper reflects the experimental results on the measurement of the expansion rate of the plasma formed during an electrical breakdown along the exploding Al foil. Electric breakdown took place in a mixture of gases that being desorbed from the surface of the foil as it heated by a current passing. Aluminum foil size: length 20 mm, thickness 6 µm and the width was varied in the range from 0.93 mm to 1.05 mm. The explosion of the foil was carried out by a sinusoidal current with an oscillation period of 1780 ns. The amplitude of the current I varied depending upon the voltage charge (Uch
= 10, 20 and 30 kV) of 0.25 µF capacitor was about 6.5, 14 and 22 kA accordingly. The measurements of the expansion rate of the plasma was carried out using three electrical probes located beneath an ground potential, near the edges and in the middle of the exploding foil, in the process, the distance from the foil to the electrical probe was varied from 2 mm to 16 mm. In the experiment we measured the time of the signal appearance relative to the moment of electrical breakdown occurrence along the foil. The rate of plasma expansion was calculated by measuring the time of plasma span from the foil to the probe with consideration of the distance to the probes.