Optical design of the tofi (time-of-flight isochronous) spectrometer for mass measurements of exotic nuclei

Abstract

The design of a novel recoil time-of-flight isochronous spectrometer for systematic mass measurements of nuclei which lie far from the valley of β-stability is described. Using a four identical cell approach, optical aberrations of the spectrometer are minimized resulting in a calculated flight-time mass resolving power of m Δm = 2000 . With the spectrometer designed for a solid angle acceptance of μ = 2.8 msr and a momentum over charge acceptance of ( Δp ze )/( p ze ) = ± 2% , use of the high intensity proton beam at LAMPF will facilitate good statistics experiments yielding new direct mass measurements with uncertainties of 30 keV to 1 MeV (depending on production rates) for nuclei with A < 70.