Research Institute of Material Science and Technology

Zelenograd, Russia

Research Institute of Material Science and Technology

Zelenograd, Russia
SEARCH FILTERS
Time filter
Source Type

Eremin V.,RAS Ioffe Physical - Technical Institute | Kiselev O.,Helmholtz Center for Heavy Ion Research | Egorov N.,Research Institute of Material Science and Technology | Eremin I.,RAS Ioffe Physical - Technical Institute | And 3 more authors.
Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment | Year: 2015

Construction of new accelerating facilities to investigate reactions with heavy ions requires upgrading of the Time-of-Flight (TOF) systems for on-line ion identification. The requested time resolution of the TOF system developed for Super FRagment Separator in the frame of the FAIR program at GSI, Germany, is in the range of tens of picoseconds, which can be realized by using planar silicon detectors. Such resolution will allow characterization of relativistic ions from Lithium to Uranium. However, fast timing of heavy ions with semiconductor detectors is expected to be limited by the so-called plasma effect due to a high concentration of electron-hole pairs in tracks. Here the results of the experiment with relativistic 197Au ions (the energy of 920 MeV per nucleon) obtained with Si detectors are described, which showed the TOF time resolution around 14 ps rms. The physical mechanism of charge collection from high-density penetrating tracks of relativistic heavy ions is considered and the analysis of timing characteristics is performed taking into account track polarization. Polarization is shown to have a strong influence on the formation of the leading edge of the detector current response generated by relativistic heavy ions, which allows us to explain the observed high time resolution. © 2015 Elsevier B.V.


Eremin V.,RAS Ioffe Physical - Technical Institute | Verbitskaya E.,RAS Ioffe Physical - Technical Institute | Eremin I.,RAS Ioffe Physical - Technical Institute | Tuboltsev Yu.,RAS Ioffe Physical - Technical Institute | And 5 more authors.
Journal of Instrumentation | Year: 2012

The NUSTAR experiments to be carried out as the part of the FAIR program (Facility for Antiproton and Ion Research) now under development in GSI, Germany, require unique spectrometers for heavy ions, for an energy range between a hundred keV up to hundreds of MeV. These spectrometers are constructed on the basis of silicon double sided detectors capable of providing simultaneously the energy spectrum of the particles and the position of hit points. The double sided Si strip detectors for high resolution ion spectroscopy and tracking were developed by the PTI-RIMST consortium. Reduced sized detectors were studied with alpha-particles from a 238Pu source to define the spectral response of their p+ side. The energy resolution was measured and found to be the highest, 9.6 keV, in the p+ strips area. The energy spectrum for the particles hit at the interstrip gap was shown to be much broader and have a maximum at the low energy edges. In this study the alpha-particle spectra were measured on the p+ side of strip detector and their shape was found to depend on the p+ strip structure and potential distribution under the strip and in the interstrip gap, where the surface is passivated by SiO2 layer. Therefore, the 2D potential distribution in the interstrip gap was simulated and interpreted through the effective entrance window for alpha-particles. The calculated spectrum of a detector from alpha-particle source has a shape specific to the experimental detector spectral response, i.e., the peak at low energies. These findings are to be taken into account in the analysis of short range particle spectra and may well contribute to further development of spectroscopic single sided and double sided Si strip detectors to be used in investigations in nuclear physics. © 2012 IOP Publishing Ltd and Sissa Medialab srl.


Verbitskaya E.,RAS Ioffe Physical - Technical Institute | Eremin V.,RAS Ioffe Physical - Technical Institute | Zabrodskii A.,RAS Ioffe Physical - Technical Institute | Dehning B.,CERN | And 5 more authors.
Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment | Year: 2015

Silicon and diamond detectors operated in a superfluid helium bath are currently being considered for the upgrade of the LHC beam loss monitoring system. The detectors would be installed in immediate proximity of the superconducting coils of the triplet magnets. We present here the results of the in situ irradiation test for silicon detectors using 23 GeV protons while keeping the detectors at a temperature of 1.9 K. Red laser (630 nm) Transient Current Technique and DC current measurements were used to study the pulse response and collected charge for silicon detectors irradiated to a maximum radiation fluence of 1×1016 p/cm2. The dependence between collected charge and irradiation fluence was parameterized using the Hecht equation and assumption of a uniform electric field distribution. The collected charge was found to degrade with particle fluence for both bias polarities. We observed that the main factor responsible for this degradation was related to trapping of holes on the donor-type radiation-induced defects. In contrast to expectations, along with formation of donors, acceptor-type defects (electron traps) are introduced into the silicon bulk. This suggests that the current models describing charge collection in irradiated silicon detectors require an extension for taking into account trapping at low temperatures with a contribution of shallow levels. New in situ irradiation tests are needed and planned now to extend statistics of the results and gain a deeper insight into the physics of low temperature detector operation in harsh radiation environment. © 2015 Elsevier B.V.


Kurfurst C.,CERN | Dehning B.,CERN | Sapinski M.,CERN | Bartosik M.R.,CERN | And 14 more authors.
Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment | Year: 2015

As a result of the foreseen increase in the luminosity of the Large Hadron Collider, the discrimination between the collision products and possible magnet quench-provoking beam losses of the primary proton beams is becoming more critical for safe accelerator operation. We report the results of ongoing research efforts targeting the upgrading of the monitoring system by exploiting Beam Loss Monitor detectors based on semiconductors located as close as possible to the superconducting coils of the triplet magnets. In practice, this means that the detectors will have to be immersed in superfluid helium inside the cold mass and operate at 1.9 K. Additionally, the monitoring system is expected to survive 20 years of LHC operation, resulting in an estimated radiation fluence of 1×1016 proton/cm2, which corresponds to a dose of about 2 MGy. In this study, we monitored the signal degradation during the in situ irradiation when silicon and single-crystal diamond detectors were situated in the liquid/superfluid helium and the dependences of the collected charge on fluence and bias voltage were obtained. It is shown that diamond and silicon detectors can operate at 1.9 K after 1×1016 p/cm2 irradiation required for application as BLMs, while the rate of the signal degradation was larger in silicon detectors than in the diamond ones. For Si detectors this rate was controlled mainly by the operational mode, being larger at forward bias voltage. © 2015 Elsevier B.V. All rights reserved.


Eremin V.,RAS Ioffe Physical - Technical Institute | Egorov N.,Research Institute of Material Science and Technology | Eremin I.,RAS Ioffe Physical - Technical Institute | Fadeeva N.,RAS Ioffe Physical - Technical Institute | Verbitskaya E.,RAS Ioffe Physical - Technical Institute
Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment | Year: 2013

In the 1990s a suggestion was put forward that the space charge limited current mechanism is responsible for stabilization of the I-V characteristics in irradiated Si p-on-n detectors. This mechanism is switched on in the case of high concentration of radiation induced deep traps which via holes accumulation will reduce the electric field in the regions of breakdown. The present study shows that voltage terminating structure (VTS) consisting of the floating p + rings as a main element for stabilization of I-V characteristics in nonirradiated detectors is still active being irradiated to the fluence beyond space charge sign inversion. This characteristic of VTS can be accounted for by the double peak electric field distribution in heavily irradiated detectors and the punch-through mechanism of current flow between the floating p+ rings in the silicon bulk with high concentration of deep traps. It is shown that VTS operates as a potential divider up to the fluence of 1×10 15 neq/cm2 and it is at higher fluences that the detector stability is maintained only by the space charge limited current mechanism. © 2013 Elsevier B.V.


Khanh T.,Mendeleev University of Chemical Technology | Mozhevitina E.,Mendeleev University of Chemical Technology | Khomyakov A.,Mendeleev University of Chemical Technology | Avetisov R.,Mendeleev University of Chemical Technology | And 6 more authors.
Journal of Crystal Growth | Year: 2016

50. mm diameter ZnSe crystals have been grown from the melt by a vertical Bridgman technique at 100. atm argon pressure in a graphite crucible. 3D impurities concentration and nonstoichiometry mappings of the grown crystals have been defined by ICP-MS and a direct physic-chemical method, correspondingly. Photoluminescence mapping of the analyzed crystal has been done. It was found out that along the crystal height the nonstoichiometry changed from Se excess over stoichiometrical composition in the cone (bottom) part to Zn excess in the tail (upper) part passing through the stoichiometrical composition in the cylindrical part of the crystal. Metal impurities concentrated in the upper part of the crystal. The gas-forming impurities (H, C, O, N, F) had stochastic distribution but Cl impurity concentrated in the crystal peripheral part (near the crucible walls). It was found out that the as-grown crystal had a single wide PL peal with maximum of 583. nm. A proposal about complex structure luminescent center based on Cl dopant an overstoichiometric Se has been made. © 2016 Elsevier B.V.


Ciannamea E.M.,Research Institute of Material Science and Technology | Stefani P.M.,Research Institute of Material Science and Technology | Ruseckaite R.A.,Research Institute of Material Science and Technology
Bioresource Technology | Year: 2010

The main goal of this work was to evaluate the technical feasibility of using rice husk (RH) as wood substitute in the production of environmentally sound medium-density particleboards using adhesives from soybean protein concentrate (SPC). Chemical modification of rice husk with sodium hydroxide and sodium hydroxide followed by hydrogen peroxide (bleaching) were undertaken to evaluate the effect of such treatments on the composition and topology of rice husk and the performance of produced panels. Both treatments were efficient in partially eliminating hemicelluloses, lignin and silica from RH, as evidenced by thermo-gravimetric analysis (TGA). Scanning electron microscopy observations suggested that alkaline treatment resulted in a more damaged RH substrate than bleaching. The dependence of mechanical properties (modulus of rupture, modulus of elasticity, and internal bond) and the physical properties (water absorption and thickness swelling) on chemical treatments performed on both, rice husk and SPC was studied. Bleached-rice husk particleboards bonded with alkaline-treated soybean protein concentrate displayed the best set of final properties. Particleboards with this formulation met the minimum requirements of internal bond, modulus of elasticity and modulus of rupture recommended by the US Standard ANSI/A208.1 specifications for M1, MS and M2-grade medium-density particleboards, but failed to achieve the thickness swelling value recommended for general use panels. This limitation of soybean protein concentrate-bonded rice husk particleboards was counterbalanced by the advantage of being formaldehyde-free which makes them a suitable alternative for indoor applications. © 2009 Elsevier Ltd. All rights reserved.


Avetissov I.,Mendeleev University of Chemical Technology | Khanh T.,Mendeleev University of Chemical Technology | Saifutyarov R.,Mendeleev University of Chemical Technology | Mozhevitina E.,Mendeleev University of Chemical Technology | And 5 more authors.
Thin Solid Films | Year: 2015

Selenium nonstoichiometry in ZnSe under bivariant and monovariant equilibriums was studied by a direct physical-chemical method. ZnSe single crystals grown from the melt and the vapor phase were used as starting materials. It was found out that at T. >. 720. K, overstoichiometric Se generates mainly electrically neutral defects. ZnSe thin films (50-300. nm) were prepared by vacuum thermal sputtering on "cold" glass substrates. To control the nonstoichiometry of the films, a specially designed two-chamber evaporator was used. The nonstoichiometry, electrical properties and morphology of the ZnSe films were investigated under various preparation conditions. It was demonstrated that it is possible to form p-n junction by varying the nonstoichiometry of ZnSe nanofilms. © 2015 Elsevier B.V.


Avetissov I.Ch.,Mendeleev University of Chemical Technology | Mozhevitina E.N.,Mendeleev University of Chemical Technology | Khomyakov A.V.,Mendeleev University of Chemical Technology | Avetisov R.I.,Mendeleev University of Chemical Technology | And 4 more authors.
CrystEngComm | Year: 2015

The homogeneity regions of zinc telluride ZnTe and cadmium telluride CdTe were studied by the "extraction" technique at 750-1365 K temperature range. It is shown that the homogeneity region of undoped ZnTe contains a stoichiometric composition. The existence of wurtzite-based ZnTe at high temperatures was proven and its lattice parameters were determined. A scheme of the 3C-2H polymorphous transition for ZnTe compounds is proposed in which the transition is followed by peritectic reactions at both the Te-rich and Zn-rich sides. In the case of CdTe, the solidus line near the melting point demonstrated an anomalous behavior, which could be explained in terms of the high-temperature polymorphous transition, but the polymorph was not fixed because of the low transition energy. The undoped ZnTe and CdTe single crystals were obtained by the Markov-Davydov vapor growth technique under pressures close to congruent sublimation conditions in the temperature range 1170-1320 K. The nonstoichiometry and impurity distribution in 60 mm diameter ZnTe and 100 mm diameter CdTe vapor grown crystals were examined. © The Royal Society of Chemistry 2015.


Avetissov I.,Mendeleev University of Chemical Technology | Chang K.,Mendeleev University of Chemical Technology | Zhavoronkov N.,Research Institute of Material Science and Technology | Davydov A.,Research Institute of Material Science and Technology | And 4 more authors.
Journal of Crystal Growth | Year: 2014

ZnSe homogeneity region was studied by direct physico-chemical method in 730-1320 K temperature range. It was established that the homogeneity region included stoichiometric composition and solidus lines both from Zn- and Se-rich sides demonstrated the retrograde behavior. Comparison of ZnSe nonstoichiometry with ionized defect concentrations at SZnSe-L(Zn)-V equilibrium had let us assert that at the examined conditions the dominant point defects are electrically neutral. Nonstoichiometry analysis of ZnSe crystals grown from melt under high pressure and from vapor by the Markov-Davydov technique showed that there were Se-excess over stoichiometry in melt grown ZnSe and Zn-excess close to stoichiometry in vapor grown crystals. © 2014 Elsevier B.V.

Loading Research Institute of Material Science and Technology collaborators
Loading Research Institute of Material Science and Technology collaborators