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 Henkel Heike Henkel Heike Henkel (born Heike Redetzky on 5 May 1964) is a German former athlete competing in high jump. She won the high jump gold medal at the 1992 Summer Olympics in Barcelona. Henkel was born in Kiel, Schleswig-Holstein. Having competed for West Germany at the Olympic Games in 1984 and 1988, she emerged as the world's leading female high jumper of the early 1990s. As well as her Olympic triumph, Henkel won World, World Indoor, European and European Indoor titles. She is one of only two female high jumpers in history to have won all five titles, the