Abstract
Ion trajectories in the extended fringing fields of an electrostatic sector analyzer have been calculated algebraically. The results of the calculations are represented by the transfer matrices for the entrance and exit fringing fields, respectively. The matrix coefficients yield a shift and bend of ion trajectories on a transformation plane at field boundaries of the sector. The effects of the extended fringing fields on image aberration can be estimated from the matrix coefficients. Large effects from the fifth order matrix coefficients have been found for the fringing fields of an electrostatic sector analyzer. The image aberration arising from the fifth order coefficients is one of the problems in obtaining high resolution with a double focusing mass spectrometer.
