Superconducting magnet issues "shaken" out of them, until they are eventually able to operate reliably at their full planned current without experiencing quenches. Although the idea of making electromagnets with superconducting wire was proposed by Heike Kamerlingh Onnes shortly after he discovered superconductivity in 1911, a practical superconducting electromagnet had to await the discovery of superconducting materials that could support large critical supercurrent densities in high magnetic fields. The first successful superconducting magnet was built by G.B. Yntema in 1955 using niobium wire and achieved a field of 0.7 T at 4.2 K. Then, in 1961, J.E. Kunzler, E. Buehler, F.S.L. Hsu,
Heike Hennig and in international festivals. Heike Hennig arranged for the former dancers of the Leipzig opera to return on stage. Ursula Cain, Christa Franze, Siegfried Prölß und Horst Dittmann, who at this time were about 80 years old, told and danced their dance and life stories which were shaped by Mary Wigman, Dore Hoyer, Gret Palucca and Heike Hennig. During the shooting, the next dance piece "Zeitsprünge (Leaps in Time)" was created. here, the protagonists meet up with their younger colleagues in the ensemble "Heike Hennig & Co" and DJ cfm. The different generations might be recognized from the various dance-styles