Realignment of a diverging electron beam: a new beam delivery system for rhodotrons

Industrially useful electron beams produced at 300 keV or more are typically generated by introducing an oscillating magnetic field near the apex of a triangular scanning horn, thus creating a diverging treatment field. Product dosing is then accomplished by conveying target material through this field. For many irradiation applications this diverging beam introduces inefficiencies in beam power utilization and dosing non-uniformity. This paper presents beam delivery systems developed by IBA for Rhodotron accelerators and, in particular, a new scan horn for delivery of a non-diverging beam.