Comparison Y-, Bi-, and Tl-compound Bulk Lenses for Relativistic Electron Beams

Previously we proposed and demonstrated lenses (Supertrons) for intense electron beams (relativistic electron beams, REBs: 340 keV, 1 kA, duration time of some nanoseconds). In the present paper, the lenses made of Y-, Bi-, and Tl-compound bulks are compared as to their REB-focusing ability in terms of a figure of merit which we proposed. The Tl-compound lens showed the highest value of the figures among the lenses. These results are ascribed to the presumably highest intracurrent density of the Tl-compounds at their operation temperature (about 86 K).