A Modified Computer Model of a Hyperbolic Energy Analyzer to Determining Its Potential for Operating as a Mass Spectrometer

Abstract

Conventional energy analyzers are used as a plasma diagnostic tool for the determination of ion and electron energy spectra and temperature, having applications in a broad range of disciplines, including molecular spectroscopy, electron microscopy, and plasma physics. In addition, in specific commercial applications in which plasma characteristics such as high density and high temperature may affect the optimization of a process, the hyperbolic energy analyzer (HEA) was developed. The HEA consists of three components: a plane parallel disc with interchangeable diameter orifices for rejection of electrons and collimation of the ion beam; a dual hyperbolic lens for particle energy selection and beam focusing; and a Faraday cup as the collector. If a potential 𝑉𝑅 is imposed on the hyperbolic lenses, then only paraxial ions with energy greater than 𝑞𝑉𝑅 can pass through the lenses and into the Faraday cup, while the remainder of the ions are discriminated against. Furthermore, while traveling through the instrument, charged particles are exposed to both magnetic and electric fields, giving a hyperbolic energy analyzer the potential for operating as a mass spectrometer, making this characteristic the objective of this research. Results from computer simulations have indicated that both the standard and the modified hyperbolic energy analyzer models can discriminate different charged particles against energy as well as separate them from a beam according to mass-to-charge values. Key Terms - Concentric Faraday Cup, Equipotential Surfaces, Hyperbolic Energy Analyzer, Hyperbolic Lenses, Mass Spectrometer.