Transport of neutrals in the outermost region of a tokamak plasmas

Abstract

The transport of neutrals in the outermost region of a tokamak plasma has been studied using kinetic theory. Analytical expressions for the density profiles of hydrogen and impurity neutrals are obtained. It is shown that the inclusion of recombination increases the density of hydrogen neutrals in the blanket region by orders of magnitude. It is also found that the major contribution to the impurity neutral density, for impurities which have a resonant mutual charge exchange with hydrogen, comes from mutual charge exchange for moderately dense plasmas whereas for dense plasmas this comes from recombination.

A possibility of local measurements of ion temperature in a high-temperature plasma by laser induced ionization

“…The estimations based on the experimental data show a high technical feasibility of spectral measurements of quenching signals in small size tokamaks. In larger tokamaks the core density of the ground state and excited hydrogen atoms remain high because of a high rate of collisional recombination of the main ions with electrons [8,9]. Therefore spectral measurements of quenching emission look also feasible in larger scale plasma machines as well.…”

Analytic kinetic treatment of neutral hydrogen atoms in a hydrogen half-space plasma with reflecting boundary and internal sources

“…The additional parts of the solution are due to the various internal neutral sources: n, is caused by the recombination neutrals, where photo-recombination is treated as a spatially constant reactive source inside the half-space (bn, = const, cp. [13]). The remaining two solution parts no, n6 are due to the line (6) (e.g., neutrals recycled from the limiter) and point ( 6) source (gas puffing e.g., at the limiter edge, t2 = tl), respectively.…”

Analytical Solutions to the Kinetic Theory of Neutrals in a Bounded Plasma Slab

“…(l.l), as employed in Refs. [4][5][6]91, is to reduce it to a differential equation. Another, mathematically more direct method is to reduced the integral equation ( 1 ion temperatures, respectively.…”