@techreport{oai:nifs-repository.repo.nii.ac.jp:00009640,
 author = {Ichiguchi,  K. and Nakajima,  N. and Okamoto,  M.},
 month = {Apr},
 note = {The Large Helical Device (LHD), which is a Heliotron/Torsatron device with two helical coils, is designed so that the current in each helical coil can be controlled independently. Unbalancing these currents leads to spatial axis configuration. It is reported here that the bootstrap current is strongly affected by the imbalance of these currents. When the ratio of the currents in the two helical coils is small enough, the bootstrap current flows in a direction so as to decrease the rotational transform because of the enhancement of the bumpiness component of the magnetic field as well as the spatial axis component. This leads to improved stability.},
 title = {Bootstrap Current in the Large Helical Device with Unbalanced Helical Coil Currents},
 year = {1997}
}