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,
Mieczysław Wolfke K. Kamerlingh-Onnes and (later) Willem Keesom studied the dielectric constant of liquid helium at various temperatures. The theoretical experiments led him to the discovery of two liquid phases of helium and solidification of helium what Mieczysław Wolfke considered as the third of his greatest achievements. In the early thirties Wolfke started to organize the separated Institute of Low Temperatures at Warsaw University of Technology, even running the first installation. In 1927 Wolfke worked on the liquid helium dielectric constant and in the next year on the association in liquid dielectrics. He also started cooperation with the Polish Army in Temporary