Physics Commons^™

Electron Transport Models And Precision Measurements With The Constant Voltage Conductivity Method, Justin Dekany, Jr Dennison, Alec Sim, Jerilyn Brunson

Graduate Student Publications

Recent advances are described in the techniques, resolution, and sensitivity of the Constant Voltage Conductivity (CVC) method and the understanding of the role of charge injection mechanisms and the evolution of internal charge distributions in associated charge transport theories. These warrant reconsideration of the appropriate range of applicability of this test method to spacecraft charging. We conclude that under many (but not all) common spacecraft charging scenarios, careful CVC tests provide appropriate evaluation of conductivities down to ≈10-22 (Ω-cm)-1, corresponding to decay times of many years.

We describe substantial upgrades to an existing CVC chamber, which improved the precision of …

Electron Energy Dependent Charging Effects Of Multilayered Dielectric Material, Gregory Wilson, Jr Dennison, Amberly Evans Jensen, Justin Dekany

Graduate Student Publications

Measurements of the charge distribution in electron-bombarded, thin-film, and multilayer dielectric samples showed that charging of multilayered materials evolves with time and is highly dependent on incident energy; this is driven by electron penetration depth, electron emission, and material conductivity. Based on the net surface potential’s dependence on beam current, electron range, electron emission, and conductivity, measurements of the surface potential, displacement current, and beam energy allow the charge distribution to be inferred. To take these measurements, a thin-film disordered SiO2 structure with a conductive middle layer was charged using 200-eV and 5-keV electron beams with regular 15-s pulses at …