Development of Electron Bombardment Ion Engine (2)

Electron Emission from Inconel under Ion Bombardment

Electron yields from clean and oxydized Inconel 625 surfaces have been measured for H', H:, Hef, 0' and Ar+ ions at normal incidence in the energy range 1.5-40 keV. These measurements have been made under ultrahigh vacuum and the samples were freed of surface contaminants by bombarding with high doses of either 20 keV H l or 30 keV Ar+ ions. Differences in yields of oxydized versus clean surfac...

Measurement of Ion a N D Electron Densities of Electron-bombardment Ion-thrustor Beam

Ion Bombardment of Interplanetary Dust

The recent discovery of ion tracks in interplanetary dust and the increasing evidence for carbon and carburized materials in these objects are strongly suggestive that chemical processing by energetic charged-particle bombardment has occurred during the dust lifetimes. The track density gives a measure of the total ion fluence experienced by the grains. We use this information and laboratory da...

Electron Bombardment of Biological Materials

A study has been undertaken of the rate of inactivation of spores of the ascomycete fungus Aspergillus niger when bombarded in vacuum, with homogeneous beams of cathode rays of energies from 4 to 15 electron kv. and current densities of 1 x 10(-7) to 3 x 10(-6) amperes per square cm. These velocities and densities are in the range of those of showers of secondary electrons produced in biologica...

Development of Ion-Bombardment Surface Treatments for Suppression of Secondary Electron Emission in Accelerator Vacuum Chambers and Other Structures

Introduction Particle accelerators have been essential tools for elementary particle physics research for many years. They are now becoming increasingly important for applied science, typically done at user facilities such as light sources and neutron sources. The performance of future high intensity positron and proton accelerators is likely to be limited by the development of electron plasma,...