Measurements have been made of the rate nu at which negative ions nucleate vortex rings in ultradilute 3He/4He solutions. It is deduced that, in strong electric fields, the average number of bound 3He per ion is controlled by a new type of quantum desorption process; and that nu0 = 10^-3 nu1 = 10^-6 nu2, where nu0, nu1 and nu2 are respectively the rates characteristic of ions with zero, one, or two bound 3He atoms.