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,
Leiden Law School result of this policy, the old Kamerlingh Onnes Laboratory, named after physicist Heike Kamerlingh Onnes, was restyled into a new home for the law school; the move was completed in 2004. A reorganisation of the faculty, which began in the 1980s, realigned the faculty's focus to major fields such as civil, corporate, notarial, criminal, European and international law; these areas remain Leiden's traditional areas of scholarly strength. The Cleveringa Institute was established in 2001 to maintain the integrity of teaching and intellectual rigour in courses. The faculty's research was moved to the E.M. Meijers Institute in 1997 and emphasised interdisciplinary