Submillisecond on-line mass separation of nonvolatile radioactive elements: An application of charge exchange and thermalization processes of primary recoil ions in helium.

Transportation of thermalized primary recoil ions from nuclear reactions by helium flow has been investigated as a means of injecting short-lived radioactive nuclides into an on-line isotope separator. Several short-lived radioactive isotopes of highly nonvolatile elements such as B, Sc, Nb, and W have been separated. The efficiency for heavy nuclides with half-lives above 1 ms is between 1 and 10%. The shortest-lived activity identified in an on-line separation is the 182-..mu..s isomeric state in /sup 207/Bi.