The cross section for dissociative recombination of vibrationally cold
D-3(+) has been measured at the ion storage ring CRYRING. The rate co
nstant at 300 K, alpha = 2.7 x 10(-8) cm(3) s(-1), is a factor of 4.3
smaller than the corresponding value for H-3(+) measured earlier in CR
YRING. An electric field of 30 V/cm was introduced in the electron-ion
interaction region. This had no measurable effect on the dissociative
recombination cross section. This suggests that the cross sections me
asured in storage rings for H-3(+) and its isotopic variants can be di
rectly compared with theoretical results once such results become avai
lable.