Electron-impact detachment of D-: Near-threshold behavior and the nonexistence of D2- resonances.

D[sup [minus]] has been stored in the heavy-ion storage ring ASTRID and merged with the electron beam from an electron cooler. The cross section for electron-impact detachment of D[sup [minus]] was measured for relative energies from 0 to 20 eV. No evidence is found for the earlier reported resonances that were ascribed to short-lived H[sup 2[minus]] states. We present a simple classical reaction-zone'' model which essentially reproduces the data except in the region close to the threshold where the cross section is small.