3. Glow Discharges and Wall Stabilized Arcs

Abstract

Publisher Summary The chapter presents a discussion on glow discharges, dielectric barrier discharges, wall stabilized arcs, electron cyclotron resonance sources, electron-beam ion trap (EBIT) sources, inductively coupled plasma sources, and capillary discharges. All of these discharges may have different ways to excite bound atomic or molecular states and to ionize constituents of the discharge, but they will all radiate both spectral line radiation and continuum radiation. In some cases, the source conditions can be controlled so one or the other of these types of radiation may dominate. The choice of a source often depends on which type of radiation is desired—for example, if a source exhibits a stable well-characterized continuum spectrum in the vacuum ultraviolet (VUV) region, then this source could be used as a secondary radiometric calibration standard throughout this spectral region. Some of the sources discussed in this chapter were designed and used as sources of spectra—that is, both line and continuum spectra as in the case of the wall stabilized arc. Some other sources that are described were designed for uses other than sources of spectra—for example, the electron cyclotron resonance tool has been primarily used as an ion source.