@techreport{oai:nifs-repository.repo.nii.ac.jp:00010181,
 author = {"Sasao,  M. and Okabe,  Y. and Fujisawa,  A. and Iguchi,  H. and Fujita,  J. and Yamaoka,  H. and Wada,  M."},
 month = {Oct},
 note = {"A plasma sputter negative ion source was studied for its applicability to the potential measurement of a fusion plasma. Both the beam current density and the beam energy spread are key issues. Energy spectra of a self extracted Au^- beam from the source were measured under the condition of a constant work function of the production surface. The FWHM increases from 3 eV to 9 eV monotonically as the target voltage increases from 50 V to 300 V, independently from the target surface work function of 2.2 - 3 eV."},
 title = {Development of Negative Heavy Ion Sources for Plasma Potential Measurement},
 year = {1991}
}