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1.
Rev Sci Instrum ; 88(7): 076109, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28764513

RESUMO

The DINA-5M diagnostic atomic beam has been upgraded to reduce the energy spread down to 50 eV. An active voltage stabilization system introduces a chain of varistors connected in series that can be switched with the time constant of 70 µs to minimize the deviation from the reference to the high-voltage level. Using deuterium, the enhanced diagnostic beam has the current of four atomic amperes and the energy of 50 keV ± 50 eV. The primary considered application is a motional Stark effect diagnostic combined with laser-induced fluorescence, where the beam energy spread is an ultimate parameter determining the measurement performance.

2.
Rev Sci Instrum ; 87(5): 056106, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27250481

RESUMO

A plane cathode composed of close-packed hexagonal LaB6 (lanthanum hexaboride) segments is described. The 6 cm diameter circular cathode is heated by radiation from a graphite foil flat spiral. The cathode along with a hollow copper anode is used for the arc discharge plasma production in a newly developed linear plasma device. A separately powered coil located around the anode is used to change the magnetic field strength and geometry in the anode region. Different discharge regimes were realized using this coil.

3.
Gig Sanit ; 94(1): 104-8, 2015.
Artigo em Russo | MEDLINE | ID: mdl-26031052

RESUMO

Monitoring of 28 indices in first/second-year female medical students during two years allowed to deliver the approximation of psychophysiological status and two patterns of educational performance during both session and examination period and according to them calculate the prognosis for these indices for two subsequent studying periods with high accuracy. Prognosis calculated upon the approximation and patterns would give the possibility to reveal negative impacts of stressor factors on students at the preliminary stage of the disease and to correct this condition with help of valeological programs.


Assuntos
Adaptação Psicológica/fisiologia , Avaliação Educacional/métodos , Nível de Saúde , Hemodinâmica/fisiologia , Monitorização Fisiológica/métodos , Estudantes de Medicina/psicologia , Feminino , Humanos , Prognóstico , Adulto Jovem
4.
Rev Sci Instrum ; 85(2): 02B108, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24593548

RESUMO

The ion source with the Penning geometry of electrodes producing continuous-wave beam of H(-) ions with current up to 25 mA was developed. Several improvements were introduced to increase source intensity, reliability, and lifetime. The collar around the emission aperture increases the electrons filtering. The apertures' diameters of the ion-optical system electrodes were increased to generate the beam with higher intensity. An optimization of electrodes' temperature was performed.

5.
Rev Sci Instrum ; 84(8): 086104, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24007124

RESUMO

The paper reports on development of the spectral motional Stark effect (MSE) diagnostic in the midplane of the gas dynamic trap (GDT) linear system for magnetic confinement of anisotropic hot-ion plasma. The axially symmetric GDT vacuum magnetic field has a minimum value in the midplane, which varies from 0.2 to 0.35 T in different regimes of operation. Buildup of 15 keV ion population generates a diamagnetic reduction of magnetic field in the plasma core of up to 30% in the maximum density region, as measured by the existing eight-line MSE diagnostic. Commissioning of the midplane MSE provided first direct measurements of diamagnetic modifications in the minimum magnetic field GDT section, a necessary complement to the understanding of equilibrium and self-organization of high-ß plasmas in GDT. Making use of the stable short-pulse diagnostic beam and calibration of the apparent spectral width of beam emission lines allow for the measurement of the plasma magnetic field of 0.29 ± 0.007 T with the integration time of 200 µs.

6.
Ross Fiziol Zh Im I M Sechenova ; 99(12): 1425-34, 2013 Dec.
Artigo em Russo | MEDLINE | ID: mdl-25464773

RESUMO

The aim of the study was to investigate 0.9% sodium chloride saline aerosol and airways electrical impedance including experiments with plastic tubes, healthy people and asthmatic patients examination using electrical impedance spirometry. The experimental part of the study consisted of measurements of the 0.9% NaCl aerosol particles size and their flow action on the electrical impedance measure in polyethylene tubes of different diameters. As a result reverse dependence between aerosol particles size, its flow intensity and electrical impedance value were revealed. In the clinical part of the study the mean values of the electrical impedance spirometry were detected in the children groups of different ages, healthy people and bronchial asthma patients. It was found that an active compound of electrical impedance spirometry was correlated with airways diameter and may be used as a criterion of bronchial obstruction syndrome. It was established that small airways disease is the basic mechanism of airways disorders in patients with control bronchial asthma, and small airways as well as large airways both are involved in not controlled bronchial asthma patients.


Assuntos
Asma/fisiopatologia , Pulmão/fisiopatologia , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Adolescente , Adulto , Criança , Pré-Escolar , Impedância Elétrica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes de Função Respiratória/métodos , Espirometria/métodos
7.
Rev Sci Instrum ; 83(2): 02B707, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22380312

RESUMO

The upgrade of the diagnostic neutral beam injector RUDI in 2010 was performed to increase the beam density at the focal plane in accordance with the requirements of charge-exchange recombination spectroscopy diagnostics. A new focusing ion-optical system (IOS) with slit beamlets and an enlarged aperture was optimized for 50% higher nominal beam current and reduced angular divergence with respect to the previous multi-aperture IOS version. The upgraded injector provides the beam current up to 3 A, the measured beam divergence in the direction along the slits is 0.35°. Additionally, the plasma generator was modified to extend the beam pulse to 8 s.

8.
Rev Sci Instrum ; 82(3): 033509, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21456739

RESUMO

An incomplete neutral beam capture can degrade the plasma performance in neutral beam driven plasma machines. The beam dumps mitigating the shine-through beam recycling must entrap and retain large particle loads while maintaining the beam-exposed surfaces clean of the residual impurities. The cathodic arc gettering, which provides high evaporation rate coupled with a fast time response, is a powerful and versatile technique for depositing clean getter films in vacuum. A compact neutral beam dump utilizing the titanium arc gettering was developed for a field-reversed configuration plasma sustained by 1 MW, 20-40 keV neutral hydrogen beams. The titanium evaporator features a new improved design. The beam dump is capable of handling large pulsed gas loads, has a high sorption capacity, and is robust and reliable. With the beam particle flux density of 5 × 10(17) H∕(cm(2) s) sustained for 3-10 ms, the beam recycling coefficient, defined as twice the ratio of the hydrogen molecular flux leaving the beam dump to the incident flux of high-energy neutral atoms, is ∼0.7. The use of the beam dump allows us to significantly reduce the recycling of the shine-through neutral beam as well as to improve the vacuum conditions in the machine.

9.
Rev Sci Instrum ; 81(2): 02B104, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20192411

RESUMO

The status and the executing modernization of RUssian Diagnostic Injector (RUDI) are described. The ion source consists of arc plasma emitter and multiaperture four-electrode ion optical system. The present ion optical system with round beamlets is to be replaced by new slit apertures system for the reducing beam angular divergence in one direction. Due to enlarged dimensions and transparency of new ion optical system the extracted ion beam current will be by 50% increased. For the extension of beam pulse duration from 4 s to 8-10 s an optimized metal-ceramic arc-discharge channel is introduced. In the paper, the optical measurements results of beam parameters, including the profile of species distribution, scanned by custom-built multichannel spectroscope, are also presented.

10.
Rev Sci Instrum ; 79(2 Pt 2): 02A521, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18315142

RESUMO

One year experience of dc H(-) source operation at 2 MeV tandem accelerator is described. The source delivers H(-) ion beams with controlled current in the range of 1-8 mA and energy up to 25 keV. Normalized 1 rms emittance for 8 mA beam is less than 0.2 pi mm mrad. Negative ions are produced on the cesiated anode of the Penning discharge, driven by plasma injection from the hollow cathode inserts.

11.
Phys Rev Lett ; 94(2): 026402, 2005 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-15698201

RESUMO

The problem of three interacting Kondo impurities is solved within a numerically exact continuous-time quantum Monte Carlo scheme. A suppression of the Kondo resonance by interatomic exchange interactions for different cluster geometries is investigated. It is shown that a drastic difference between the Heisenberg and Ising cases appears for antiferromagnetically coupled adatoms. The effects of magnetic frustrations in the adatom trimer are investigated, and possible connections with available experimental data are discussed.

12.
Phys Rev Lett ; 90(10): 105002, 2003 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-12689003

RESUMO

In the axially symmetric magnetic mirror device gas dynamic trap (GDT), on-axis transverse beta (ratio of the transverse plasma pressure to magnetic field pressure) exceeding 0.4 in the fast ion turning points has been first achieved. The plasma has been heated by injection of neutral beams, which at the same time produced anisotropic fast ions. Neither enhanced losses of the plasma nor anomalies in the fast ion scattering and slowing down were observed. This observation confirms predicted magnetohydrodynamic stability of plasma in the axially symmetric mirror devices with average min-B, like the GDT is. The measured beta value is rather close to that expected in different versions of the GDT based 14 MeV neutron source for fusion materials testing.

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