Measuring the Density of a Molecular Cluster Injector via Visible Emission from an Electron Beam

[摘要] A method to measure the density distribution of a dense hydrogen gas jet is pre- sented. A Mach 5.5 nozzle is cooled to 80K to form a flow capable of molecular cluster formation. A 250V, 10mA electron beam collides with the jet and produces H?? emission that is viewed by a fast camera. The high density of the jet, several 10¹⁶cm^-3, results in substantial electron depletion, which attenuates the H_?? emission. The attenuated emission measurement, combined with a simplified electron-molecule collision model, allows us to determine the molecular density profile via a simple iterative calculation.

[发布日期] 2010-06-28

[学科分类] 原子、分子光学和等离子物理

[关键词] DISTRIBUTION;ELECTRON BEAMS;ELECTRON-MOLECULE COLLISIONS;ELECTRONS;HYDROGEN;MOLECULAR CLUSTERS;NOZZLES Fueling;Beams;Electron;Atomic and Molecular Phyysics