Experiments Directed to Creation of Hot Plasma with β~1 at the GOL-3-II Facility

Two experiments directed to a search the experimental conditions for the creation of the hot plasma bunch with β~1 at the multimirror trap GOL-3-II are described. In the first one the hydrogen cloud of 0.5 m length and ~10¹⁶ density cm⁻³ was heated in a short (~ 0.5 m) section with relatively small magnetic field placed in the 12-m solenoid with 9 T magnetic field in mirrors. Plasma pressure was measured by diamagnetic loops and reached β_vac ≈0.4. In the second experiment the dense bunch is created by pellet (LiD, (CH₂)_n) injection into the electron-beam-heated plasma. After beginning of the beam injection the pellet is evaporated and ionized, then dense plasma is magnetized and as result dense bunch (n_e=10¹⁶-10¹⁷cm⁻³) with abrupt edges is created. After heating the bunch has expansion velocity up to 3·10⁷cm/s.