Experimental study of integrated characteristics of plasma stream and discharge of a quasi-stationary high-current plasma accelerator with its own magnetic field

Abstract

Quasistationary high-current plasma accelerators (QSPAs) are currently being actively used to test plasma-facing components (PFCs) of the ITER tokamak and to study the erosion of materials under intense energy fluxes. As a promising area of application of QSPA, there are also technologies for plasma processing of materials and the development of powerful electric jet plasma engines. These tasks are need to QSPA operation in new modes, which, in turn, requires optimization of the plasma accelerator for providing the certain range of plasma stream parameters, coordination with the power source for achieve an acceptable efficiency, and ensuring stability. In this connection, experimental studies of the relationship between the parameters of the plasma flux and the discharge characteristics in the accelerator are relevant. These studies are the subject of this work. In the QSPA operation modes for PFCs testing, the efficiency of the transfer of plasma flux energy to target absorbed energy, as well as the efficiency of plasma flux energy conversion into radiation, was investigated. In these modes, for hydrogen plasma flow with duration of 0.5 ms and energy content of up to 150 kJ, it has been demonstrated that the efficiency of the accelerator can be greater than 80%, and the efficiency of converting the energy of the stream into plasma radiation is up to 40%. The obtained experimental data are necessary for the development of a new research direction related to the introduction of an additional longitudinal magnetic field in the QSPA in combination with the control of the parameters of the gas flow at the entrance to the acceleration channel. This research direction is need for development the stability of QSPA operation in a wider range of parameters.