SECONDARY ELECTRON CAPTURE ISOTOPES AS TESTS FOR THE REACCELERATION OF COSMIC RAY NUCLEI

John A. Simpson and J.J. Connell
	University of Chicago, Chicago, Illinois USA

Although reacceleration of the cosmic radiation propagating throughout the interstellar medium has been proposed by many investigators, adequate tests for reacceleration -- such as with secondary electron capture isotopes -- only became realizable with the high resolution isotope instruments on the Ulysses and ACE spacecraft. Although reacceleration is implicit in interstellar shock acceleration and turbulence models, its significance for interstellar propagation has not been established. If fully ionized cosmic rays experience reacceleration, then these nuclei will have spent time at lower energies where electron capture has a higher probability than at higher energies. We have shown earlier from our Ulysses measurements of the abundance ratio of V-49 to V-51 that reacceleration is likely. In the present report we discuss further the evidence for reacceleration based on the electron capture isotopes.