10:45 AM - 11:00 AM
[PCG18-01] Development of a ultra-small mass spectrometer for future lunar and planetary exploration
★Invited Papers
Keywords:Ultra-small, Exploration, in-situ analysis, Mass spectrometry
Mass spectrometers have been widely employed as payloads for planetary exploration missions. Those are instruments that measure the atoms and molecules in samples, and can be widely applied to quantitative and qualitative analysis (e.g., analysis of elemental and isotopic compositions). In this study, we are particularly developing a neutral mass spectrometer that measures neutral gas samples. Similar instruments were used in the past missions, such as Rosetta/ROSINA (Balsiger et al. 2006), which measured the composition of the coma of comet 67P/Churyumov-Gerasimenko, and MAVEN/NGIMS (Mahaffy et al. 2015), which measured the escaping Martian upper atmosphere. Due to the universal availability, neutral mass spectrometers are expected to be utilized in many future missions (e.g., LUPEX/REIWA/TRITON).
One of the characteristics of mass spectrometers is that they are instruments for in-situ analysis. Unlike remote sensing such as spectroscopic and telescopic observations, mass spectrometers should be in close to the target bodies, and thus reducing the resources of mass spectrometers is an important task in expanding the targets of exploration. In addition, space exploration missions using small satellites such as CubeSat are expected to become more active in the future alongside flagship missions, and the development of a mass spectrometer that can be applied for ultra-small exploration missions is a major theme.
Therefore, we are developing an ultra-small neutral mass spectrometer that fits into a volume of <1U (<10×10×10 cm3). The mass spectrometer being developed is based on time-of-flight (TOF-MS) technique, and an Orbitrap-type electrodes (Makarov, 2000) are employed to increase time-of-flight while reducing resources. The electrodes allow the ions to pass around the same optical system, achieving a longer time-of-flight with the ultra-small size. So far, we developed a test model, and the volume of the optical system was ~7×7×8 cm3. As for performance, for a single lap test, the mass resolution was m/Δm ~ 50, the sensitivity was ~1×10-6 (counts/s)/(particle/cc), and the detection limit (i.e., S/N=1) was~1×104 particle/cc, respectively. In addition, we have also completed a design with an improved mass resolution to obtain mass spectra for more than 2 laps, using a numerical simulation. According to the results of the simulation, the improved mass resolution will be achieved with an additional gate electrode that switches the voltage from +100 V to -300 V within 10 ns. As a future work, we are planning to develop the gate electrode and conduct performance tests of the improved design.
One of the characteristics of mass spectrometers is that they are instruments for in-situ analysis. Unlike remote sensing such as spectroscopic and telescopic observations, mass spectrometers should be in close to the target bodies, and thus reducing the resources of mass spectrometers is an important task in expanding the targets of exploration. In addition, space exploration missions using small satellites such as CubeSat are expected to become more active in the future alongside flagship missions, and the development of a mass spectrometer that can be applied for ultra-small exploration missions is a major theme.
Therefore, we are developing an ultra-small neutral mass spectrometer that fits into a volume of <1U (<10×10×10 cm3). The mass spectrometer being developed is based on time-of-flight (TOF-MS) technique, and an Orbitrap-type electrodes (Makarov, 2000) are employed to increase time-of-flight while reducing resources. The electrodes allow the ions to pass around the same optical system, achieving a longer time-of-flight with the ultra-small size. So far, we developed a test model, and the volume of the optical system was ~7×7×8 cm3. As for performance, for a single lap test, the mass resolution was m/Δm ~ 50, the sensitivity was ~1×10-6 (counts/s)/(particle/cc), and the detection limit (i.e., S/N=1) was~1×104 particle/cc, respectively. In addition, we have also completed a design with an improved mass resolution to obtain mass spectra for more than 2 laps, using a numerical simulation. According to the results of the simulation, the improved mass resolution will be achieved with an additional gate electrode that switches the voltage from +100 V to -300 V within 10 ns. As a future work, we are planning to develop the gate electrode and conduct performance tests of the improved design.