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Ivanov, V. V.

Publications and source records attributed to Ivanov, V. V..

An experimental platform for investigation of the Zeeman effect in strong magnetic fields

An experimental platform is developed for the investigation of the Zeeman effect in strong magnetic fields. Mega-Gauss magnetic fields are generated by a 1 MA Zebra pulsed power machine using metal rod loads. A gas jet or CH oil on the load is the source of hydrogen. Excited hydrogen atoms are backlit by black body radiation from the rod load. Hydrogen absorption spectra are recorded with a grating spectrometer and intensified gated CCD camera. Furthermore, the experimental platform enables the observation of the quadratic Zeeman effect in hydrogen gas jets using the spectral shift of the central line in the Zeeman triplet. Other gases can be studied using the gas jet method.

47 OTHER INSTRUMENTATION↗

Quadratic Zeeman effect in hydrogen at 2–3 MG magnetic fields

The Zeeman effect is used for measurement of magnetic fields in astrophysical and laboratory plasmas. Magnetic fields in atmospheres of magnetic white dwarf stars are in the range 40 kG–1 GG. The quadratic Zeeman effect results in the additional split and shift of lines for magnetic fields >2 MG. Hydrogen Balmer lines were studied in magnetic fields delivered by a 1 MA pulse power generator. The magnetic field was generated by rod loads 0.8–1 mm in diameter. A droplet of CH oil on the load center was the source of hydrogen. A low ionized oil layer was backlit by blackbody emission from the rod with a temperature of 0.5–0.6 eV. Zeeman splitting of H-alpha and H-beta absorption lines were with a grating spectrometer. A spectral shift of the central component of the triplet indicated the quadratic Zeeman effect in hydrogen lines.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

Generation of strong magnetic fields for magnetized plasma experiments at the 1-MA pulsed power machine

Pulsed power technology provides a platform for investigating plasmas in strong magnetic fields using a university-scale machine. Presented here are methods for generating and measuring the 1–4-MG magnetic fields developed for the 1-MA Zebra pulsed power generator at the University of Nevada, Reno. A laser coupled with the Zebra generator produces a magnetized plasma, and experiments investigate how a megagauss magnetic field affects the two-plasmon decay and the expansion of the laser-produced plasma in both transverse and longitudinal magnetic fields.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

Study of laser-driven magnetic fields with a continuous wave Faraday rotation diagnostic

Magnetic fields driven by a laser in coil targets were studied for laser energies of ~25 J and two pulse durations of 2.8 ns and 70 ps. Axial magnetic fields in the coils were measured by continuous wave Faraday rotation diagnostics. The diagnostics indicated magnetic fields of 6–14 T in the coil and currents of 10–20 kA. Magnetic fields were compared for similar laser targets, focusing conditions, and laser energies. A 30-times increase in the intensity of the laser beam by reducing the pulse duration resulted in an increase in the magnetic field and current by a factor of 2. The relaxation time of the magnetic pulse was on the sub-microsecond scale.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

Modeling magnetic confinement of laser-generated plasma in cylindrical geometry leading to disk-shaped structures

Radiation-magnetohydrodynamic simulations were able to reproduce features of the plasma structures observed in recent experiments1, where a laser was used to ablate plasma in a 3 MG magnetic field. The laser ablates the plasma, and localized structures are formed due to the inhibition of heat flow by the magnetic field. The large magnetic pressures cause the plasma to pinch. In an azimuthal fi eld, a disc-shaped plasma is generated. According to simulations, the disc has electron densities that are underdense to the laser, ranging from 10 18 to 10 19 cm -3 , and electron temperatures in the 300 to 1000 eV range during its evolution, similar to experimental data.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

Visualization of the 3-dimensional flow around a model with the aid of a laser knife

A method for visualizing the three-dimensional flow around models of various shapes in a wind tunnel at a Mach number of 5 is described. A laser provides a planar light flux such that any plane through the model can be selectively illuminated. The shape of shock waves and separation regions is then determined by the intensity of light scattered by soot particles in the flow.

Borovoy, V. Y.↗

Dependence of vestibular reactions on frequency of action of sign-variable accelerations

It was revealed that during the tests with continuous action of sign variable Coriolis acceleration the development of kinetosis was proportionate to the time of head inclinations in the range of 1 to 4 seconds while illusions of rocking in sagittal plane was more expressed in fast inclinations. The obtained data provided the evidence of sufficient dependence of vestibulovegetative and vestibulosensory reactions on the period of repetition of sign variable Coriolis acceleration.

Lapayev, E. V.↗

Soyuz 22: New contribution to earth study from space

The mission of space flight Soyuz-22 was to develop new and improved methods and means for finding tthe Earth's natural resources from outer space to aid the economy. With the help of the new multispectral space camera, MKF-6, the cosmonauts were able to photograph selected areas of U.S.S.R. and the German Democratic Republic in 4 visible and 2 infrared regions of the spectrum. The MKF-6 can simultaneously photograph areas in 6 spectral regions and register both the natural electromagnetic radiation of surface objects and the solar radiation reflected by them.

Vedeshin, L. A.↗