抄録
The dynamics of the evaporated material which is formed around the solid hydrogen pellet subject to a plasma is studied. Basic equations are transformed into ordinary differential equations by the profile method, and solved numerically. In this analytical model, it is assumed that the evaporated pellet material is a neutral molecular gas and the phase equilibrium exists at the pellet surface, and that the electron energy flux is attenuated by the elastic scattering with the neutral molecules. The electron energy flux coming into the pellet surface is calculated using the electron transport equation in a spherical shell coordinate system. This transport equation prevalently includes the effects of the scattering and the absorption of the electron by the evaporated material and also the emission of the electron from the pellet and the evaporated material.
Numerical results are obtained by changing parametrically τ0 characterizing the extinction of incident electrons to the pellet surface. The time dependence of the pellet radius and the outer radius of the evaporated material is obtained. For τ0=0.01, the outer radius of the evaporated material is about six times of the initial radius and the life time of the pellet is 10-2 times compared with previous results. Also it is shown that the electron scattering in the evaporated material will be important to evaluate the electron energy flux.
