Two‐dimensional magnetic field evolution measurements and plasma flow speed estimates from the coaxial thruster experiment

1994 ◽  
Vol 1 (9) ◽  
pp. 3115-3131 ◽  
Author(s):  
D. C. Black ◽  
R. M. Mayo ◽  
R. A. Gerwin ◽  
K. F. Schoenberg ◽  
J. T. Scheuer ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Plasma Flow ◽  
Flow Speed ◽  
Two Dimensional ◽  
Field Evolution ◽  
Plasma Flow Speed

Observations of two-dimensional magnetic field evolution in a plasma opening switch

1998 ◽  
Vol 5 (3) ◽  
pp. 792-798 ◽  
Author(s):  
R. Shpitalnik ◽  
A. Weingarten ◽  
K. Gomberoff ◽  
Ya. Krasik ◽  
Y. Maron
Keyword(s):  
Magnetic Field ◽  
Two Dimensional ◽  
Plasma Opening Switch ◽  
Opening Switch ◽  
Field Evolution

scholarly journals Long-Term Independence of Solar Wind Polytropic Index on Plasma Flow Speed

Entropy ◽  
2018 ◽  
Vol 20 (10) ◽  
pp. 799 ◽  
Author(s):  
George Livadiotis
Keyword(s):  
Solar Wind ◽  
Plasma Flow ◽  
Solar Wind Speed ◽  
Solar Wind Plasma ◽  
Flow Speed ◽  
Polytropic Index ◽  
Solar Cycles ◽  
Solar Wind Proton ◽  
Plasma Flow Speed

The paper derives the polytropic indices over the last two solar cycles (years 1995–2017) for the solar wind proton plasma near Earth (~1 AU). We use ~92-s datasets of proton plasma moments (speed, density, and temperature), measured from the Solar Wind Experiment instrument onboard Wind spacecraft, to estimate the moving averages of the polytropic index, as well as their weighted means and standard errors as a function of the solar wind speed and the year of measurements. The derived long-term behavior of the polytropic index agrees with the results of other previous methods. In particular, we find that the polytropic index remains quasi-constant with respect to the plasma flow speed, in agreement with earlier analyses of solar wind plasma. It is shown that most of the fluctuations of the polytropic index appear in the fast solar wind. The polytropic index remains quasi-constant, despite the frequent entropic variations. Therefore, on an annual basis, the polytropic index of the solar wind proton plasma near ~1 AU can be considered independent of the plasma flow speed. The estimated all-year weighted mean and its standard error is γ = 1.86 ± 0.09.

Particle and energy transport due to magnetic field-line reconnection in a tokamak

1987 ◽  
Vol 37 (3) ◽  
pp. 335-346
Author(s):  
Satoru Iizuka ◽  
Yasujiroh Minamitani ◽  
Hiroshi Tanaca
Keyword(s):  
Magnetic Field ◽  
Field Line ◽  
Magnetic Field Line ◽  
Energy Transport ◽  
Flow Speed ◽  
Poloidal Magnetic Field ◽  
Reconnection Region ◽  
Field Lines ◽  
Plasma Flow Speed ◽  
Current Reversal

Plasma behaviour during magnetic field-line reconnection which is driven by a rapid toroidal current reversal in a tokamak is investigated by calculating plasma flow speed from the magnetohydromatic equations with variables measured in the experiment. A strong plasma acceleration appears in the outside region of the X-type separatrix formed in the poloidal magnetic field lines. The induced electric field inside the plasma is evaluated directly from Ohm's law by using the fact that the toroidal current density vanishes during the current reversal. Then, plasma resistivity is estimated in the cross-section and the resulting value of energy flow is compared with that given by Poynting's theorem. It is found that the input energy is dissipated effectively through anomalous resistivity in the reconnection region.

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