Application of a small angular spread beam in the reflected REB regime on REBEX machine

The possible increase of the heating efficiency by application of a beam with smaller angular spread (Θ≈10°) in the reflected beam regime is discussed. The pitch angle of peripheral beam electrons is substantially reduced (Θ<;10°) also for the beam with high current density (≤5 kA.cm^-2) by increasing the external magnetic field. The modified REBEX facility has already passed the first tests. The preliminary results of the plasma diamagnetism by 0.5 kJ REB injection are presented.