Plasma heating experiments with ten microsecond reb at multimirror trap GOL-3

Summary form only given. Essential progress was achieved in experiments on heating the dense plasma in the multimirror trap GOL-3 by high power relativistic electron beam in last few years. The beam parameters at the experiments were the following: electron energy ~1 MeV, beam current ~25 kA, beam current density in plasma ~2 kA/cm², pulse duration about 10 ms, total energy of the beam pulse -150 kJ. Due to the high level of the current density and effect of a novel mechanism of ion heating the temperature of ions reached 2-3 keV at the electron temperature about 3 keV for the plasma density ~10 cm^-3. Energy confinement time of the plasma in these experiments has reached the level of 1 ms. The basic condition of such parameters achievement is anomalously low electron thermal conductivity along the trap axis which is provided by small scale Longmuir turbulence developing as a result of two-stream instability. In order to analyze a prospect of further increase of plasma parameters for reaching a fusion area, to elongate the beam pulse duration was decided. As the first step on solving this task we are performing the experiments at the accelerator U-2 on 1.5 fold increase of the E-beam duration. To investigate in more details the process beam-plasma interaction we carry out measurements on temporal dynamics of the plasma electron distribution function in the range of 0-5 keV and on evolution of energy distribution functions of the beam electrons as well. We also measure an electromagnetic radiation gone out from the plasma column as result of transformation of two Langmuir waves in electromagnetic one in strong turbulent plasma. This electromagnetic radiation is measured in the frequency band 210-550 GHz. Results of the pointed experiments and their discussion are presented in this paper.