The solar wind as a flui1

The solar wind as a flui1 - The solar wind as a fluid...

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The solar wind as a fluid However, if the solar wind were "organised" by other forces in some way, it may have an effective collision cross-section between particles that is larger (and therefore an effective shorter mean free path, f e ). One candidate might be Coulomb forces. The parameter that defines how significant Coulomb forces are in comparison with the thermal energy acting to separate them, is the Landau Length , L. We define L as the mean free path derived assuming a collision cross- section given by the deflection of particles due to Coulomb collisions: Here we see the deflection produced by Coulomb attraction as a charged particle passes close to another (assumed for simplicity here to be so large it doesn't move itself). We can see that the deflecting particle now has an effective cross-sectional area given by the radius r e , and we can find this approximately by assuming it is the distance scale at which the Coulomb potential energy is approximately equal to the kinetic energy (ie the thermal energy). Thus:
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This note was uploaded on 12/15/2011 for the course AST AST1002 taught by Professor Emilyhoward during the Fall '10 term at Broward College.

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The solar wind as a flui1 - The solar wind as a fluid...

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