Excitation Properties and Cryogenic Stability of Helical Coils for the LHD. - Imagawa, S.; Yanagi, N.; Mito, T.; Chikaraishi, H.; Hamaguchi, S.; Yamada, S.; Satow, T.; Nakamura, Y.; Satoh, S.; Motojima, O. (IEEE Transactions on Applied Superconductivity, 2001)