Design and Optimization of A Multi-reflection Time-of-flight Mass Spectrometer for LPT

Multi-reflection time-of-flight mass spectrometer (MRTOF-MS) has been developed as a new device which has a higher mass resolving power than traditional mass spectrometers in recent years. A new method including two sub-procedures, global search and local refinement, has been developed and applied to design a MRTOF-MS. It consists of two components, parameter configuration and ion motion simulation, and can be used to optimize the geometries of the spectrometer and the potentials applied on the electrodes to achieve the optimum in different conditions. By using this method, a different type of MRTOF mass analyzer has been designed for mass measurements and isobaric separation for Lanzhou Penning Trap (LPT). The geometry of this analyzer and potentials at different electrodes have been optimized, and the relations between resolving power and potentials and the power accuracy requirements have been analyzed and discussed quantitatively. The simulation shows that the optimal length of the drift-tube is about 400 mm; the maximal resolving power of 1.3×10⁵ has been achieved with a total time-of-flight of 6.5 ms under the optimal potentials for an ion species of ⁴⁰Ar¹⁺; and the inaccuracy of the potentials applied to the mirror electrodes must be less than 50 ppm or preferably 20 ppm.