Theory and MHD simulation of fuelling process by compact toroid (CT) injection
Y. SUZUKI, Naka Fusion Research Establishment, JAERI, Naka 311-0193, Japan.
Abstract.
The new theoretical model, which determines the penetration depth of a compact toroid (CT) injected into a magnetized target plasma region, is represented from the result of MHD simulations. In the penetration process, the CT is influenced by the plasma compressibility, the magnetic pressure force, the magnetic tension force and magnetic reconnection between the CT magnetic field and the target one and so on. In this study, we examine how these physical mechanisms affect the penetration process of the CT. As a result, it is revealed that 1) the magnetic tension force, which is caused by the bent target magnetic field whose wavelength is longer than the CT size, effectively decelerates the CT, 2) magnetic reconnection between the CT magnetic field and the target magnetic field relaxes the CT deceleration. The new theoretical model is constructed so that these complex processes can be taken into account. In addition, we discuss the dynamics of the CT in a drift tube, which is important to successfully guide the CT from a CT gun.