Validation and comparison of nonlinear negative ion extraction theory for two experimental configurations J.H. Whealton, P.S. Meszaros, R.J. Raridon, K.E. Rothe, M. Bacal, J. Bruneteau et P. DevynckRev. Phys. Appl. (Paris), 24 9 (1989) 945-949DOI: https://doi.org/10.1051/rphysap:01989002409094500