Confinement characteristics of low density FRC plasma

A new ionization process of the working gas through the fast neutral particle is utilized in order to assist in the formation of the field reversed configuration plasma. This method improves the lower density limit of the formed plasma. Characteristics of the field reversed configuration plasma are investigated in the low density region of the order of 1 x 1020 m-3 for the fusion plasma core. The particle confinement time τN is larger than the expected value of the coefficient from the empirical scaling by a factor of 2.8. It is found that the flux decay time τφ and the energy decay time τE are obtained to be τφ = 0.89τN and τE = 0.41τN, respectively, in the low density region. (author)