Calculation of a mass-spectrometer with a sector magnet, an electrostatic prism and a transaxial lens

We have considered a static mass-spectrometer with a double focusing beam, which is used in combination with a uniform sector magnetic field, a three electrode electrostatic prism and a transaxial lens. The chosen electrostatic system not only ensures focusing of the beam on energy, but also vastly increases the beam before entering in the magnetic field. This, in combination with the theorem on the "quality" parameter, allows greater resolution of the mass-spectrometer. The electric and magnetic fields of the mass-spectrometer are given analytically. By numerical integration of the differential equations the trajectories of the charged particles in curvilinear coordinates are calculated and the characteristics of the mass-spectrometer are deduced. This enables the parameters for the mass-spectrometer to be chosen. (C) 2008 Elsevier B. V. All rights reserved.