Numerical simulations and experiments of simultaneous acceleration of positive and negative ions in a radio frequency quadrupole
X. Q. Yan, Y. R. Lu, J. X. Fang, Z. Y. Guo, X. T. Ren, J. X. Yu, Y. Xie, and C. E. Chen
Phys. Rev. ST Accel. Beams 9, 020101 (2006) - Published 1 February, 2006