Direct Measurements of Masses of Short Lived Nuclei: 74–79Rb 90–99Rb, 117–124,126Cs and 138,140–147Cs

Abstract

The possibility of using mass spectrometric techniques to determine the masses of short lived radioactive isotopes was investigated in 1970 after the successfull measurements of short half lives using on line mass spectrometry1. At the AMCO IV conference -1971- two projects were presented; one from the Minnesota group2 using a double focusing mass spectrometer and the other from the Orsay group3 using a single stage instrument. At the AMCO V conference -1975- the results of the direct measurements of the masses of Li and 26–32Na were presented by Thibault et al.4. They showed that an accuracy of 100 keV could be reached for light elements even with a single stage mass spectrometer and that the masses of a chain of isotopes could be determined in a single experiment, both facts would allow us to gain information on the global properties of the nuclear mass surface as well as on the local peculiarities of nuclear structure.