An on-line mass separator for fission-produced alkali isotopes

Abstract The design of an on-line mass separator installed at the TRIGA reactor in Mainz is described and its performance discussed. A tungsten oven, filled with about 2 g of 235U embedded in graphite, is exposed to a flux of 1.7 × 1011 thermal neutrons (s− cm−2) near the reactor core. After diffusion out of the graphite the fission-produced alkali isotopes are surface-ionized and electromagnetically mass-separated, the resolving power being about 750. Losses during the diffusion out of the target material are discussed. Due to these losses the maximum separator efficiency is about 5%, corresponding to a source strength of about 109 particles s−1 for the most abundant isotopes. The heaviest…

Determination of nuclear spins of short-lived Rb and Cs isotopes by β radiation detected optical pumping