IMPROVEMENT OF THE MERGED-BEAM METHOD AND ITS APPLICATION TO THE STUDY OF THE REACTION - H--]H+HE(HE+)

It is shown that two parallel ion beams react at a rate that is indepe ndent of their density profiles when made to oscillate against each ot her in a two-dimensional scanning motion. An experimental set-up that makes use of this principle is described. Absolute cross sections obta ined in this way are in good agreement with those obtained with the be ams merging in the usual (static) mode. Cross sections for single-char ge transfer between H-(D-) and He+ in the energy range 5-4000 eV are p resented and compared to other existing data.