@article{oai:nifs-repository.repo.nii.ac.jp:00000392,
 author = {NARUSHIMA,  Y. and WATANABE,  K.Y. and SAKAKIBARA,  S. and OHYABU,  N. and YAMADA,  H. and NARIHARA,  K. and YAMADA,  I. and MORISAKI,  T. and INAGAKI,  S. and NAGAYAMA,  Y. and KOMORI,  A. and LHD, exp. group and COOPER,  W.A.},
 journal = {Plasma and Fusion Research},
 month = {Jan},
 note = {Characteristics of magnetic islands are investigated by magnetic diagnostics in the Large Helical Device (LHD). The structure of the magnetic island with m/n = 1/1 (where, m and n are poloidal and toroidal mode number, respectively) can be estimated from the perturbed magnetic field appearing when a magnetic island changes. To measure the toroidal profile of the perturbed magnetic field δb1  originating from the plasma, a toroidal array of magnetic flux loops is set up in the LHD. The toroidal profile of δb1 is then spatially Fourier decomposed to determine the amplitude of the n = 1 component, δb1n=1  and its phase, φn=1 which correspond the change of the island width and the toroidal position of the X-point of the island, respectively. Therefore, the information about the magnetic island structure can be obtained from δb1n=1 and φn=1. In case the island width becomes larger than the seed island, measurements show that δb1n=1 is non-zero and φn=1  is temporally constant. A non-zero δb1n=1 can also be observed when the island width becomes smaller than the seed island. In this case, the angle φn=1 shifts by about π[rad] compared with the increasing case and the δb1n=1 is limited to a certain value which corresponding to the magnetic field suppressing the seed island.},
 title = {Magnetic Diagnostics of Magnetic Island in LHD},
 volume = {Vol.2},
 year = {2007}
}