DISSOCIATIVE RECOMBINATION OF HD-BEAM IN A COOLER RING( WITH AN ULTRACOLD ELECTRON)

Dissociative recombination of HD+ was studied with an adiabatically ex panded low-temperature electron beam in a cooler ring TARN II. Measure ments were performed over a wide energy range from 0 to 40 eV in the c enter of mass system. The spectrum at low electron energies less than 1 eV clearly shows structures even in the energy region of the order o f 1 meV. The results agree well with the theoretical calculations base d on a multichannel quantum defect theory including rotational motions and off-the-energy-shell effects.