Titanium (Ti)-coated multiwall carbon nanotubes (CNTs) emitters based on the magnetron sputtering process are demonstrated, and the influences of modification to CNTs on the residual gas adsorption, gas desorption, and their field emission characteristic are discussed. Experimental results show that Ti nanoparticles are easily adsorbed on the surface of CNTs due to the “defects” produced by Ar⁺ irradiation pretreatment. X-ray photoelectron spectroscopy (XPS) characterization showed that Ti nanoparticles contribute to the adsorption of ambient molecules by changing the chemical bonding between C, Ti, and O. Field emission of CNTs coated with Ti nanoparticles agree well with the Fowler–Nordheim theory. The deviation of emission current under constant voltage is 6.3% and 8.6% for Ti-CNTs and pristine CNTs, respectively. The mass spectrometry analysis illustrated that Ti-coated CNTs have a better adsorption capacity at room temperature, as well as a lower outgassing effect than pristine CNTs after degassing in the process of field emission.

Low energy ion measurements in the vicinity of a comet have provided us with important information about the planet’s evolution. The calibration of instruments for thermal ions in the laboratory plays a crucial role when analysing data from in-situ measurements in space. A new low energy ion source based on carbon nanotube electron emitters was developed for calibrating the ion-mode of mass spectrometers or other ion detectors. The electron field emission (FE) properties of carbon nanotubes (CNTs) for H₂, He, Ar, O₂, and CO₂ gases were tested in the experiments. H₂, He, Ar, and CO₂ adsorbates could change the FE temporarily at pressures from10⁻⁶ Pa to10⁻⁴ Pa. The FE of CNT remains stable in Ar and increases in H₂, but degrades in He, O₂, and CO₂. All gas adsorbates lead to temporary degradation after working for prolonged periods. The ion current of the ion source is measured by using a Faraday cup and the sensitivity is derived from this measurement. The ion currents for the different gases were around 10 pA (corresponding to 200 ions/cm³ s) and an energy of ~28 eV could be observed.

In this study, a cylindrical triode ultrahigh vacuum ionization gauge with a screen-printed carbon nanotube (CNT) electron source was developed, and its metrological performance in different gases was systematically investigated using an ultrahigh vacuum system. The resulting ionization gauge with a CNT cathode responded linearly to nitrogen, argon, and air pressures in the range from ~4.0 ± 1.0 × 10⁻⁷ to 6 × 10⁻⁴ Pa, which is the first reported CNT emitter-based ionization gauge whose lower limit of pressure measurement is lower than its hot cathode counterpart. In addition, the sensitivities of this novel gauge were ~0.05 Pa⁻¹ for nitrogen, ~0.06 Pa⁻¹ for argon, and ~0.04 Pa⁻¹ for air, respectively. The trend of sensitivity with anode voltage, obtained by the experimental method, was roughly consistent with that gained through theoretical simulation. The advantages of the present sensor (including low power consumption for electron emissions, invisible to infrared light radiation and thermal radiation, high stability, etc.) mean that it has potential applications in space exploration.

Gravity waves (GWs) are important for understanding the coupling between dust activity and atmospheric dynamics on Mars. Using temperature and water-vapor profiles from the Near-Infrared channel of the Atmospheric Chemistry Suite (ACS-NIR) onboard the ExoMars Trace Gas Orbiter (TGO), we investigate wave-related temperature perturbations during global and regional dust-storm periods. Comparisons between Mars Years (MY) 34 and 35 reveal a localized enhancement of wave-related perturbations at southern high latitudes, particularly between 60°S and 90°S and 40–90 km. This enhancement persists after controlling for differences in observational sampling. The gravity-wave-related potential-energy proxy is approximately 2–3 times larger during the MY34 global dust storm, with a weaker enhancement during the regional event. These variations coincide with substantial differences in background temperature, static stability, and zonal winds, suggesting that dust-related changes in the atmospheric environment may modify wave propagation and filtering. Water-vapor abundance is also higher in the same region, but is more likely associated with dust-driven large-scale circulation, while wave-related processes may provide additional local modulation. These results provide observational constraints on dust–wave–water coupling in the Martian middle atmosphere.

HCGs are widely used for ultra-high vacuum and space vacuum measurements due to their high-sensitivity and long-term stability. However, the indicated pressure of an HCG may deviate from the actual chamber pressure because the operating conditions during application differ from those during calibration. This deviation is particularly relevant for balance-chamber HCGs used in space vacuum measurements, where the ionization region is connected to the external vacuum environment through multistage conductance channels, leading to complex molecular transport behavior. In this study, the pressure deviation mechanism of balance-chamber HCGs is investigated by considering the coupled effects of thermal transpiration, thermal outgassing, and structural conductance. Based on free molecular flow theory and the Maxwell–Boltzmann velocity distribution, a pressure model is developed to describe the relationship between the internal gauge pressure and the external chamber pressure. The contributions of temperature gradients, outgassing sources, and structural parameters are analyzed through numerical simulations and experimental measurements. The results indicate that thermal transpiration is the dominant factor affecting pressure deviation at relatively higher pressures. With decreasing pressure, thermal outgassing from heated internal components becomes increasingly significant and limits the measurement accuracy in the ultra-high vacuum range. A structure-dependent correction exponent was introduced to account for the influence of the balance chamber on thermal transpiration behavior. After correction, the prediction deviation of the proposed model is reduced to within ±1%. The proposed model provides a quantitative approach for evaluating pressure deviations in HCGs with complex internal structures and improves the reliability of pressure interpretation for space vacuum measurements