Kinetic based fluid model.

J Egedal, W Fox, N Katz, A Le, A Vrublevskis, J Bonde,

A Soane & M Porkolab

MIT, PSFC, Cambridge, MA

Thanks to: M Øieroset, R Lin, J Drake and W Daughton

Basic geometry and assumptions

Trapped electron in simulation by W Daughton

Electrostatic and Magnetic Trapping

Combined magnetic and electrostatic trappingwill ensure quasi neutrality

Electrostatic & Magnetic Trapping:

++++

V||

V

++++

•From Vlasov’s equation df/dt=0

Similar trap observed with Open & closed BCs

J Drake

W Daughton

M. Øieroset et al. Nature 412, (2001)

M. Øieroset et al. PRL 89, (2002)

Wind spacecraft observations in distant magnetotail, 60RE

• Measurements within the ion diffusion region reveal: Strong anisotropy in fe.

Log(f)

trap~1kV J. Egedal et al., PRL (2005)

Model vs. Numerical Distributions

Kinetic Fluid Model

Likewise:

From codeFrom (n,B)mi/me =180

Kinetic Fluid Model

From codeFrom (n,B)mi/me =180

Kinetic Fluid Model

From codeFrom (n,B)mi/me =180

Kinetic Fluid Model

Converges with increasing mass ratio

From codeFrom (n,B)mi/me =360

Up shot: New fluid model!

Ohm’s law:

Aydemir 1992

Compare to: