An Improvement of Secondary Emission Detector for Energy Analysis of Charge-Exchange Neutrals Emitted from High-Temperature Plasma

Abstract

Secondary emission detector (SED) is improved for ion temperature measurement of high-temperature plasma by charge-exchange neutral analysis. This improvement is based on the incident energy (E) dependency of the ratio of secondary electron yield for an incident angle θ to that for normal incidence, defined as k( θ, E). The ratio k( θ, E) is investigated as functions of E and θ for hydrogen atom incidence. To examine and demonstrate the usefulness of the improved SED, both experimental simulation and computer simulation of the charge-exchange neutral analysis with the improved SED are used. In the experimental simulation, facsimile neutrals are produced by neutralization of an ion beam on a solid surface and are analyzed by the improved SED. The result is compared with that obtained by using normal charge-stripping type analyzer. In the computer simulation, a simple model of the charge-exchange neutral emission of high-temperature hydrogen plasma is assumed and the usefulness of the improved SED as a hydrogen plasma diagnostic technique is evaluated under the influences of strong plasma radiation conditions.