Observation of focused electron beams inside a high-Tc bulk superconductor lens (supertrons)

Focusing of intense electron beams (340 keV, 0.8 kA, and 10 ns) was confirmed visually inside a high-Tc bismuth-based bulk superconductor lens (Supertrons) with image fibers. The electron beams were focused to 1.1 mm in diameter (full width at half-maximum) at the exit of the lens, the narrowest beams which have been achieved with Supertrons.