Experimental studies of the magnetic structure and plasma dynamics in current sheets (a review)

2017 ◽  
Vol 43 (6) ◽  
pp. 696-710 ◽  
Author(s):  
A. G. Frank ◽  
N. P. Kyrie
Author(s):  
Joseph E. Borovsky

If MHD turbulence is a dominant process acting in the solar wind between the Sun and 1 AU, then the destruction and regeneration of structure in the solar-wind plasma is expected. Six types of solar-wind structure at 1 AU that are not destroyed by turbulence are examined: 1) corotating-interaction-region stream interfaces, 2) periodic density structures, 3) magnetic structure anisotropy, 4) ion-composition boundaries and their co-located current sheets, 5) strahl-intensity boundaries and their co-located current sheets, and 6) non-evolving Alfvénic magnetic structure. Implications for the solar wind and for turbulence in the solar wind are highlighted and a call for critical future solar-wind measurements is given.


2007 ◽  
Vol 25 (3) ◽  
pp. 347-363 ◽  
Author(s):  
P.V. Nickles ◽  
S. Ter-Avetisyan ◽  
M. Schnürer ◽  
T. Sokollik ◽  
W. Sandner ◽  
...  

New perspectives have been opened up in the field of laser–matter interactions due to recent advances in laser technology, leading to laser systems of high contrast and extreme intensity values, where the frontier of maximum intensity is pushed now to about 1022 W/cm2. Many striking phenomena such as laser-acceleration of electrons up to the GeV level, fast moving ions with kinetic energies of several 10s of MeV, as well as nuclear physics experiments have already actuated a broad variety of theoretical as well as experimental studies. Also highly relativistic effects like laser induced electron-positron pair production are under discussion. All these activities have considerably stimulated the progress in understanding the underlying physical processes and possible applications. This article reviews recent advances in the experimental techniques as well as the associated plasma dynamics studies at relativistic intensities performed at the Max-Born-Institute (MBI). Interactions of a laser pulse at intensities above 1019 W/cm2 with water- and heavy-water droplets, as well as, with thin foils are discussed. Rear and front side acceleration mechanisms, particle dynamics inside the dense target, proton source characteristics, strong modulations in proton and deuteron emission spectra, and finally generation of quasi-monoenergetic deuteron bursts are the topics covered in the article.


2007 ◽  
Vol 33 (6) ◽  
pp. 435-443 ◽  
Author(s):  
S. Yu. Bogdanov ◽  
S. G. Bugrov ◽  
V. P. Gritsyna ◽  
O. V. Zverev ◽  
G. V. Karpov ◽  
...  

2018 ◽  
Vol 848 ◽  
pp. 256-287 ◽  
Author(s):  
N. C. Hurst ◽  
J. R. Danielson ◽  
D. H. E. Dubin ◽  
C. M. Surko

The dynamics of two-dimensional (2-D) ideal fluid vortices is studied experimentally in the presence of an irrotational strain flow. Laboratory experiments are conducted using strongly magnetized pure electron plasmas, a technique which is made possible by the isomorphism between the drift–Poisson equations describing plasma dynamics transverse to the field and the 2-D Euler equations describing an ideal fluid. The electron plasma system provides an excellent opportunity to study the dynamics of a 2-D Euler fluid due to weak dissipation and weak 3-D effects, simple diagnosis and precise control. The plasma confinement apparatus used here was designed specifically to study vortex dynamics under the influence of external flow by applying boundary conditions in two dimensions. Additionally, vortex-in-cell simulations are carried out to complement the experimental results and to extend the parameter range of the studies. It is shown that the global dynamics of a quasi-flat vorticity profile is in good quantitative agreement with the theory of a piecewise-constant elliptical patch of vorticity, including the equilibria, dynamical orbits and stability properties. Deviations from the elliptical patch theory are observed for non-flat vorticity profiles; they include inviscid damping of the orbits and modified stability limits. The dependence of these phenomena on the flatness of the initial profile is discussed. The relationship of these results to other theoretical, numerical and experimental studies is also discussed.


2011 ◽  
Vol 116 (A9) ◽  
pp. n/a-n/a ◽  
Author(s):  
Z. J. Rong ◽  
W. X. Wan ◽  
C. Shen ◽  
X. Li ◽  
M. W. Dunlop ◽  
...  

2006 ◽  
Author(s):  
G. Ostrovskaya ◽  
A. Frank ◽  
S. Bogdanov ◽  
G. Dreiden ◽  
V. Markov

Universe ◽  
2021 ◽  
Vol 7 (11) ◽  
pp. 400
Author(s):  
Anna G. Frank ◽  
Natalya P. Kyrie ◽  
Sergey N. Satunin ◽  
Sergey A. Savinov

The characteristic features of plasma acceleration in the current sheets are discussed on the basis of an analysis of the structure of electrodynamic forces at successive stages of the evolution of the current sheets formed in the plasma with helium ions. Of particular interest is the generation of reverse currents at the side edges of the sheet and the appearance of forces, which are braking previously accelerated plasma flows.


2011 ◽  
Vol 18 (11) ◽  
pp. 111209 ◽  
Author(s):  
Anna G. Frank ◽  
Natalya P. Kyrie ◽  
Sergey N. Satunin

Author(s):  
Kent McDonald ◽  
David Mastronarde ◽  
Rubai Ding ◽  
Eileen O'Toole ◽  
J. Richard McIntosh

Mammalian spindles are generally large and may contain over a thousand microtubules (MTs). For this reason they are difficult to reconstruct in three dimensions and many researchers have chosen to study the smaller and simpler spindles of lower eukaryotes. Nevertheless, the mammalian spindle is used for many experimental studies and it would be useful to know its detailed structure.We have been using serial cross sections and computer reconstruction methods to analyze MT distributions in mitotic spindles of PtK cells, a mammalian tissue culture line. Images from EM negatives are digtized on a light box by a Dage MTI video camera containing a black and white Saticon tube. The signal is digitized by a Parallax 1280 graphics device in a MicroVax III computer. Microtubules are digitized at a magnification such that each is 10-12 pixels in diameter.


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