Performance evaluation of a miniature LWMA MS designed for in situ lunar investigations

Abstract

There is still no direct evidence for the existence of water ice and organic matter on the moon. The main goal of developing a miniature time-of-flight mass spectrometer (TOF MS), Lunar Water Molecular Analyzer Mass Spectrometer (LWMA MS), is to detect water ice, organic matter and other chemical components in situ on the moon. The miniature LWMA MS in this paper is composed of sampling introduction tube, gas charge tube, ion source, TOF mass analyzer and detector. The SIMION software was used to simulate the miniaturization design of the ion source and mass analyzer. Meanwhile, the developed miniature TOF MS was evaluated systematically. Its resolution is 151 for water and 163 for nitrogen, the mass range is from 1 to 500 amu, the stability of water is 3% during 12 h. Moreover, it was proved that the developed LWMA MS is able to detect water ice and organic matter through the experiments of the lunar soil simulant.