2.2 Time pattern
The typical measurement cycle is as follows: First, ions are generated by atmospheric pressure ionization and introduced into the instrument through the capillary inlet. In the API region, the diameter of the ion beams can be reduced to the submillimeter range by collision action in the RFQs. Then, the ions are transferred to the FLT and trapped by the voltage of the endcaps switched up. After a final cooling in the FLT, the ions are ejected orthogonally, accelerated by the AC, and ion-optically adjusted by the ST and DT. Finally, the ions enter the MRTOF analyzer and reflect back and forth, increasing the ion flight distance from meters to hundreds of meters or even kilometers. After a predetermined number of reflections, the ejection endcap switches down and allows the ions travel to a micro-channel plate ion detector (MCP, R3809U, Hamamatsu). The timings for the FLT ejection and both mirror endcaps switching are mass dependent (as shown in Fig. 2), thus requiring a precalculated timing pattern.