title: Angular scattering of 1-50 keV ions through graphene and thin carbon foils: potential applications for space plasma instrumentation.
abstract: We present experimental results for the angular scattering of ~1-50 keV H, He, C, O, N, Ne, and Ar ions transiting through graphene foils and compare them with scattering through nominal ~0.5 μg 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 μg cm(-2) carbon foils used in space-based particle detectors. At energies less than 50 keV, the scattering angle half width at half maximum, ψ(1/2), for ~3-5 atoms thick graphene is up to a factor of 3.5 smaller than for 0.5 μg cm(-2) (~20 atoms thick) carbon foils. Thus, graphene foils have the potential to improve the performance of space-based plasma instruments for energies below ~50 keV.
authors.affiliation: Southwest Research Institute, P. O. Drawer 28510, San Antonio, Texas 78228-0510, USA.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Ebert
authors.affiliation: Southwest Research Institute, P. O. Drawer 28510, San Antonio, Texas 78228-0510, USA.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Allegrini
authors.affiliation: Southwest Research Institute, P. O. Drawer 28510, San Antonio, Texas 78228-0510, USA.
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Fuselier
authors.affiliation: Southwest Research Institute, P. O. Drawer 28510, San Antonio, Texas 78228-0510, USA.
authors.forename: Georgios
authors.initials: G
authors.lastname: Nicolaou
authors.affiliation: Lockheed Martin Advanced Technology Center, 3251 Hanover Street, Palo Alto, California 94304, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Bedworth
authors.affiliation: Lockheed Martin Advanced Technology Center, 3251 Hanover Street, Palo Alto, California 94304, USA.
authors.forename: Steve
authors.initials: S
authors.lastname: Sinton
authors.affiliation: Lockheed Martin Advanced Technology Center, 3251 Hanover Street, Palo Alto, California 94304, USA.
authors.forename: Karlheinz J
authors.initials: KJ
authors.lastname: Trattner