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Session 101 - The Sun.
Display session, Thursday, January 18
North Banquet Hall, Convention Center
The existence of a very thin layer over which the magnetic field reverses is a main element in the process of magnetic reconnection. I present an example of the creation of the reconnection layer from the equilibrium state in which the layer is not initially present. In particular, I consider a one dimensional situation in which a magnetic field initially varies linearly, passing through zero at the origin. The magnetic pressure force is initially balanced by gas pressure, so it is in equilibrium. In order to form the layer spontaneously, we allow plasma to recombine. Thus, the pressure drops, the system goes out of equilibrium and further compression occurs. As the time progresses the adiabatic compression continues and a finite current layer of decreasing thickness forms. For even a very small resistivity the layer becomes sufficiently thin for the destruction of the magnetic field. We are able to treat the evolution of the layer analytically all the way from the initial equilibrium through the reconnection until all the flux is destroyed. Under the idealized assumptions, we determine the reconnection time to be proportional to square root of the effective magnetic Reynolds number (R_M=L^2 \gamma/\eta, where \gamma is the initial recombination rate, \eta is resistivity and L is the initial size of the system).
Program listing for Thursday