A Simulation and Optimization Method Based on Numerical Analysis for Rectilinear Ion Trap

A simulation and optimization method for rectilinear ion trap (RIT) was introduced. The protocol for this method is implemented in principle according to verification experiments. On the basis of numerical analysis, second-order differential equations were obtained to describe the movements of ions in the RIT. The equations were solved by the Runge-Kutta method and the conditions for stability of ions in the ion trap were obtained under ideal conditions which represented the ability of the RIT to catch and trap the ions. An RIT was designed and optimized according to the optimal conditions. In this study, ethanol vapour was ionized by a UV discharge lamp and the RIT was used as a mass analyzer during the verification experiment. The ethanol ions were detected by a Faraday cup. The mass spectrum of ethanol was obtained successfully with mass range up to 260 amu/e and the method proved to be practical and correct. The numerical analysis is simple, well-targeted and easy to modify. The loops could be used to find out the optimal structure and parameter, so the method is suitable for the research on RIT. Furthermore, simulation software could be developed based on it. The method is of high manoeuvrability and possesses a vast range of applications prospect.

The facilities for RIT experiment was introduced in this study. The facilities comprised a UV lamp (ion source), a pinch valve (sample injection), a Hicube80E vacuum pump, a homemade vacuum chamber, a faraday cup detector and a RIT. The volatile ethanol gas and carrier gas (nitrogen) were mixed as the sample gas.Figure optionsDownload as PowerPoint slide