Study of the FLG transferring technique on grids and the particle angular scattering characteristics for next-generation space TOF instruments with higher mass resolution

Carbon foils are widely used in time-of-flight (TOF, a measurement method that derives particle velocity from flight time over a defined spatial interval) mass spectrometers. Yet their accuracy is constrained by thickness-induced scattering and fragility. Atom-thick and possessing superior mechanical strength, graphene introduces less angular scattering and delivers improved mass resolution, thereby offering a compelling alternative for space-based TOF systems. Nonetheless, the application of graphene into such systems remains constrained by challenges in transferring it onto mesh grids, which is a key step for its integration into TOF systems. Hence, to achieve an optimal balance among minimal thickness, high graphene coverage, and a high grid open fraction, we optimized and adapted a graphene transfer technique suitable for space applications and successfully prepared several few-layer graphene (FLG, graphene with more than 3 atomic layers) samples using this technique. These samples, with 2 nm thickness, a grid open fraction of 40%, and a graphene coverage exceeding 95%, were subsequently irradiated with ion beams to characterize their angular scattering behavior, yielding half-width at half-maximum (HWHM) values and scattering half-angles. Computer simulation of the angular scattering experiment was also conducted to validate the experimental measurements. For FLG, scattering half-angles ranged from 1.33° to 4.76°. Under identical ion species and energy conditions, carbon foils exhibited scattering half-angles between 1.56° and 11.02°. These results indicate that FLG induces less angular scattering than carbon foils, thereby enhancing measurement accuracy in TOF systems. These findings demonstrate the potential of FLG for next-generation space plasma instruments and provide a foundation for further investigation. Further development of large-area (>1 × 1 cm) FLG transfer techniques is still recommended for practical space application.