A FOURIER-TRANSFORM TIME-OF-FLIGHT MASS-SPECTROMETER - A SIMION CALCULATION APPROACH

A new kind of approach to time-of-flight type spectrometers is present ed on the basis of SIMION calculations. The detector studied is a shor t cylindrical tube capacitor closed with parallel plates at both ends. The main principle of operation is to force ions of equal energy to c irculate in the volume between the two tubes on a path of equal radius and measure their flight times pro revolution which corresponds to th e frequency of oscillation. By performing spectral analysis on the rec eived signal through transformation from the time domain to frequency space the different masses can be detected. To study the expected perf ormance of the FT-TOF detector, calculations of ion trajectories have been made by varying the dimensions and electric potentials of the ele ctrodes. The effect of the beam position, variations in the angle of e ntrance and ion energy to the trajectories was calculated to monitor t he resolution that is achievable.