A time-of-flight mass spectrometer to resolve isobars

In order to determine nuclear binding energies of short-lived nuclei we have developed a multi-pass time-of-flight mass spectrometer in which ions are repeatedly reflected between two coaxially arranged electrostatic ion mirrors. These ions are passed up to several hundred times between the ion mirrors. Within this system the overall ion flight time can be several milliseconds and the overall flight distance more than 100 m. There are no intensity losses in the grid-free ion mirrors and the transmission is limited only by angle scattering of the ions by residual gas atoms. The achieved mass resolving power exceeded m/Δm∼40,000