Photo-ionization and Cherenkov ring imaging

Publisher Summary This chapter presents a survey of previous works in related fields, coupled with current experience in the environmental scanning electron microscope (ESEM). This microscope allows the examination of specimens in the presence of a gaseous environment. The scintillation produced by various signals can also be used for making images, and a generalized gaseous detector device (GDD) was proposed. GDD is based on the principle of classical gaseous particle detectors adapted to the specific requirements of the ESEM. The chapter presents an account of the new terminology associated with ESEM. Physical principles for the analysis of ESEM are electron and ion temperature, imaging parameters, theory of induced signal, and induced signals in the ESEM. Whereas, the physical parameters involved in the performance of the GDD are electron and ion mobilities, diffusion, recombination, electron attachment, and effective ionization energy. The chapter outlines the discharge characteristics and accounts for amplification, parallel plates; the first Townsend coefficient; the Paschen law; and secondary processes. The ESEM is a radiation source immersed inside a gas, and, therefore, the methods of nuclear and particle physics for spectroscopic analysis can be applied. Principles of spectroscopy including spectroscopy, statistics, and energy resolution and environmental scanning transmission electron microscopy are discussed. The chapter focusses on mechanisms of a high gaseous gain.

Theory of the Gaseous Detector Device in the Environmental Scanning Electron Microscope

Y. Fujita

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