About new method of ESR of large-size hollow ingots - B. B. Fedorovskij; L. B. Medovar; A. P. Stovpchenko; V. M. Zhuravel; Ja. Saenko; V. A. Zajtsev; V. B. Smoljarko; V. A. Lebed (Electrometallurgy Today, 2011)