Tilt stability of field-reversed configurations

By means of the two-fluid model in which the ion fluid is rigidly rotating with finite temperature and the electron fluid is at rest in equilibrium, the internal tilt stability of a field-reversed configuration (FRC) is studied theoretically. In contrast with previous theoretical studies, it is found that the elongated FRCs can be stabilized when both the elongation and scale factors are suitably chosen. Comparison of the present results with the experiments is made. (author)