Abstract
Ion optics for the high performance mass spectrometer is investigated. In order to estimate the characteristics of a mass spectrometer numerically, a performance factor, PF, and an aberration factor, AF, are introduced and defined. The PF is defined as a product of four factors related to C/X (C, mass dispersion; X, image magnification), deflection angle of magnetic sector, total path length and ion beam transmission through magnet gap. Each factor consists of a ratio compared to the value for 180° magnetic analyzer. The AF is defined as a maximum resolving power calculated from the simulated image under the incident ion beam conditions of 1% spread of α, δ, y, β.
Almost perfect higher order focusing and high performance are attained by mass spectrometers with the field arrangement of QQHQC and QQQHQC (Q, quadrupole; H, homogeneous magnetic sector; C, cylindrical electric sector). In these mass spectrometers, the value of PF reaches 100 and that of AF 260,000.
