Mass Dependence of Cross Section Fluctuation in Dissipative Reaction ^(19)F+^(51)V

Excitation functions for projectile-like fragments from ^(19)F+^(51)V reaction have been measured at 102.25 to 109.50MeV in 250keV steps.A TOF+(ΔE-E)telescope atθ_(L)=21.7°is used to identify atomic number Z and mass number A of ejectiles simultaneously.Fluctuations of the dissipative cross section for a series of isotopes are observed.Their coherence energy widths are extracted by generalized statistical fluctuation analysis and the dependence on mass number and on N/Z values are observed for the first time.