Experimental tests of the von Karman self-preservation hypothesis: decay of an electron plasma to a near-maximum entropy state

Details Experimental tests of the von Karman self-preservation hypothesis: decay of an electron plasma to a near-maximum entropy state Experimental tests of the von Karman self-preservation hypothesis: decay of an electron plasma to a near-maximum entropy state

Dec 2009

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009agufmsm43b1760r&link_type=abstract

American Geophysical Union, Fall Meeting 2009, abstract #SM43B-1760

Physics

Plasma Physics

[2159] Interplanetary Physics / Plasma Waves And Turbulence, [4490] Nonlinear Geophysics / Turbulence, [7831] Space Plasma Physics / Laboratory Studies And Experimental Techniques, [7863] Space Plasma Physics / Turbulence

Scientific paper

The self-preservation hypothesis of von Karman [1] implies that in three dimensiolnal turbulence the energy E decays as dE/dt = - a Z^3/L, where a is a constant, Z is the turbulence amplitude and L is a simlarity length scale. Extensions of this idea to MHD [2] has been of great utility in solar wind and coronal heating studies. Here we conduct an experimental study of this idea in the context of two dimensional electron plasma turbulence. In particular, we examine the time evolution that leads to dynamical relaxation of a pure electron plasma in a Malmberg-Penning (MP) trap, comparing experiments and statistical theories of weakly dissipative two-dimensional (2D) turbulence [3]. A formulation of von Karman-Howarth (vKH) self-preserving decay is presented for a 2D positive-vorticity fluid, a system that corresponds closely to a 2D electron ExB drift plasma. When the enstrophy of the meta-stable equilibrium is accounted for, the enstrophy decay follows the predicted vKH decay for a variety of initial conditions in the MP experiment. Statistical analysis favors a theoretical picture of relaxation to a near-maximum entropy state, evidently driven by a self-preserving decay of enstrophy. [1] T. de Karman and L. Howarth, Proc. Roy. Soc Lon. A, 164, 192, 1938. [2] W. H. Matthaeus, G. P. Zank, and S. Oughton. J. Plas. Phys., 56:659, 1996. [3] D. J. Rodgers, S. Servidio, W. H. Matthaeus, D. C. Montgomery, T. B. Mitchell, and T. Aziz. Phys. Rev. Lett., 102(24):244501, 2009.

Affiliated with

Also associated with

No associations

Rating

Experimental tests of the von Karman self-preservation hypothesis: decay of an electron plasma to a near-maximum entropy state does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Experimental tests of the von Karman self-preservation hypothesis: decay of an electron plasma to a near-maximum entropy state, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Experimental tests of the von Karman self-preservation hypothesis: decay of an electron plasma to a near-maximum entropy state will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1880656