The Fusion Edge Plasma Models

The plasma fluid equations, in their classical form, for magnetized plasmas as in fusion devices, are given, for example, in the fundamental work by Braginskii [10]. 

In order to obtain reduced sets that can be solved numerically, parameter ordering and symmetry assumptions are made such that the essential physics is still contained. An important ingredient is a set of boundary conditions consistent with these choices. Such boundary conditions have recently been reviewed, [11], 

In practise, the upper principal quantum number n is limited by Lorentz ionization. For hydrogen it is given roughly by 

O is the angle between the particle trajectory and the field B, E is the kinetic energy and A is the atomic number. Typical conditions in present fusion experiments are 

A linear algebraic system of rate equations for the fast species results, which can be solved a priori. Hence a strongly reduced (in the number of species to be treated) system is obtained. This concept originates from astrophysical applications and from Laser physics. It is in some instances also referred to as collisional-radiative approximation , for the fast species, lumped species concept , bundle-n method or intrinsic low dimensional manifold (ILDM) method in the literature. We refer to [9,12,13] for further references on this. 

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