Measurement of photoemission and secondary emission from laboratory dust grains

摘要: The overall goal of this project is experimentally determine the emission properties dust grains in order to provide theorists and modelers with an accurate data base use codes that predict charging various plasma environments encountered magnetospheres planets. In general these values which have been measured on planar, bulk samples materials question. large enhancements expected due small size can a dramatic impact upon predictions ultimate utility predictions. first experimental measurement energy resolved profiles secondary electron coefficient, 6, sub-micron diameter particles has accomplished. Bismuth range .022 .165 micrometers were generated moderate pressure vacuum oven (average function temperature pressure) introduced into high chamber where they interacted beam (0.4 20 keV). Large observed peak value, delta(sub max) = 4. 5 for ensemble mean micrometers. This contrast published 1.2, bismuth. are agreement recent theoretical made by Chow et al. at UCSD.