Formation and investigation of an intense rotating electron beam and its interaction with solid materials

Summary form only given, as follows. To test ITER divertor candidate materials and to check the physical models for calculation of divertor material erosion under plasma disruptive conditions experiments on formation and dynamics of target plasma and on material erosion and structural modification are to be performed. The most convenient instrument for such investigations besides the Tokamak itself is a powerful electron beam. Pulse durations larger than 100 /spl mu/s and beam power densities around 5 MW/cm/sup 2/ are required. For such an electron beam facility the beam parameters at the target can be measured and controlled rather easily. In order to achieve an energy deposition close to the target surface the longitudinal kinetic energy of the electrons has to be transferred into transverse energy (gyrational motion). In this case magnetized electrons under guidance of perpendicular magnetic field lines enter the target under small angles and thus resulting in a decrease of the range and an increase of the stopping power. This idea was realized in the ELDIS facility. The transformation of longitudinal energy of the electrons into transverse energy is achieved in a compression channel with downstream increasing magnetic field. The paper gives a discussion of results of numerical simulation of electron beam formation and its realization in ELDIS. For solid targets and for plasmas results of Monte Carte stopping power calculations are given for different ratios of longitudinal to transverse beam energies at constant total energies of 120 keV. Experimentally determined properties of target plasma and results of target erosion are presented.