Angular scattering of 1-50 keV ions through graphene and thin carbon foils: Potential applications for space plasma instrumentation

We present experimental results for the angular scattering of similar to 1-50 keV H, He, C, O, N, Ne, and Ar ions transiting through graphene foils and compare them with scattering through nominal similar to 0.5 mu g cm(-2) carbon foils. Thin carbon foils play a critical role in time-of-flight ion mass spectrometers and energetic neutral atom sensors in space. These instruments take advantage of the charge exchange and secondary electron emission produced as ions or neutral atoms transit these foils. This interaction also produces angular scattering and energy straggling for the incident ion or neutral atom that acts to decrease the performance of a given instrument. Our results show that the angular scattering of ions through graphene is less pronounced than through the state-of-the-art 0.5 mu g cm(-2) carbon foils used in space-based particle detectors. At energies less than 50 keV, the scattering angle half width at half maximum, psi(1/2), for similar to 3-5 atoms thick graphene is up to a factor of 3.5 smaller than for 0.5 mu g cm(-2) (similar to 20 atoms thick) carbon foils. Thus, graphene foils have the potential to improve the performance of space-based plasma instruments for energies below similar to 50 keV. (C) 2014 AIP Publishing LLC.