Fusion plasma confinement research at the gas dynamic trap

A so called vortex confinement of plasma in axially symmetric mirror device was studied. This recently developed approach enables to significantly reduce transverse particle and heat losses typically caused by MHD instabilities which can be excited in this case. Vortex confinement regime was established by application of different potentials to the radial plasma limiters and end-plates. As a result, the sheared plasma flow at periphery appears and wraps the plasma core. Experiments were carried out at the Gas Dynamic Trap device, where hot ions with a mean energy of E_h≈9 keV and the maximum density of energetic ions n_h≈5·10¹⁹m^-3 were produced by oblique injection of deuterium or hydrogen neutral beams into a collisional warm plasma with the electron temperature up to 250 eV and density n_w≈2·10¹⁹m^-3. Local plasma α approaching 0.6 was measured. The measured transverse heat losses were considerably smaller than the axial ones. The measured axial losses were found to be in a good agreement with the results of numerical simulations. Recent experimental results support the concept of the neutron source based on the gas dynamic trap.