It has been proposed that the binding energies of positrons to a number of
atoms can be determined by the charge transfer reaction A(-) + e(+) --> e()A + e(-). This reaction can be realized in the laboratory by intersecting
a negative ion beam with a positron beam. The existence of e(+)A and the de
termination of its binding energy can be shown by detecting the charge tran
sfer electrons and measuring their energies.