Abstract
A new type of double-focusing mass spectrometer (DF/MS) has been designed. The instrument is a reversed-geometry type DF/MS and makes use of toroidal electrodes and specifically shaped pole pieces of the magnet in order to improve the second-order aberration coefficients. The toroidal electrodes with a field index of 0.5 form the concave entrance and exit surfaces. The magnet supplies a homogeneous field and its pole pieces form concave entrance and oblique exit surfaces. The feature of the present ion optics system is in making the ion beam which emerges out of the ion source slit (Si) converge solidly onto the collector slit (Sc).
The ion optics system has been designed by means of the newly developed computer program which takes into accunt the recent results of the theory on the ion beam. One can search for the resolutions by inputting the criterion values for the second-order aberration coefficients into the program.
