Experiments with "Thin" Electron Beam at GOL-3

The latest experimental campaign at the GOL-3 multiple-mirror trap was mainly aimed at features of heating and stability of the electron-beam-heated turbulent plasma. The discussed experiments feature a reduced-cross-section electron beam with the current decreased down to 1 [divided by] 1.5 kA at the current density of ~1 kA/cm² (the same as in the “full-scale” experiments). The hot plasma cross-section decreased correspondingly.

Lowered current of the electron beam became less than the critical vacuum current. This gives the possibility to make a direct comparison of regimes with the beam injection into a neutral or a preliminary ionized deuterium. New experimental results will be presented on the beam relaxation in the plasma and on heating and stability of the reduced-cross-section plasma with low central safety factor q(0) ~ 0.3. Stabilization of some MHD modes by a controlled coupling of the plasma with an exit receiver plate was demonstrated.