Thermal deformation analysis of a 3D printed Kingdon ion trap for the Moon environment

Abstract

Soil analysis is a significant part of space exploration. Nowadays, great attention is given to soil investigation on the Moon, and special missions are being planned to carry out analyses of lunar soil in situ (Valero et al., 2007). Mass spectrometry is a proven method that is commonly used for identifying the chemical composition of the soil. One of the best candidates for a mass spectrometer for this purpose is a mass spectrometer based on an ion trap, which has high mass resolution, a low weight, a compact size, and low power consumption. Among the existing ion traps (Kingdon traps, Penning traps, Radiofrequency Paul traps, and Radiofrequency linear traps), a Kingdon trap of unique design would be a viable option for many applications.However, disturbances in the space environment negatively affect the use of an ion trap. One of these harmful effects in the lunar environment is the wide range of temperatures. Heating or cooling causes deformation of the geometry of the ion trap electrodes, reducing the accuracy of the measurements.The current research aims to compare metal and ceramic ion traps and to investigate how the material used in manufacturing affects the performance of the mass spectrometer. Analysis of thermally-induced deformations was used as the primary method of the research. We manufactured models of metal and ceramic ion traps, analyzed the effects of electrode deformation on the analytical characteristics of the mass spectrometer, conducted thermal deformation analysis, and validated our results.The ceramic ion trap (56.3 µm) shows less thermal deformation in comparison with the metal one (105.5 µm). The thermal expansion that is higher than 50 µm significantly affects the performance of the instrument. The loss time of the signal decreased twice reduces the resolution of the ion trap also by a factor of two. We propose introducing corrections to the shape of the surface that electrodes have at room temperature so that after thermal compression at 97 K (average temperature of the Moon Polar regions), the surface has a shape corresponding to the ideal performances of the instrument.