Absolute cross sections for electron impact ionization, dissociative excita
tion (DE) and dissociative ionization of N-2(+) ions are measured in the en
ergy range from threshold to 2500 eV. The animated crossed electron-ion bea
m method has been employed. The individual contributions of ionization prod
ucts (N-2(2+)) and dissociation fragments (N+), which have both identical m
ass-to-charge ratio and average velocity, are deduced from the analysis of
product velocity distributions. Particular attention was paid to determinin
g the transmission efficiency for dissociation fragments, since their colle
ction was incomplete during the measurements. Threshold energies and kineti
c energy released to dissociation fragments are measured. The role of state
s contributing to different reactions is discussed. For DE, the present res
ults are found to be much smaller than the results of Peterson et al (1998)
. For ionization (single and dissociative), a satisfactory agreement with t
heir result is obtained as well as with the prediction of Kim et al (2000)
obtained in the binary-encounter Bethe approximation.