Search

The dynamic Stark effect is a phenomenon in which photon(s) associated with an oscillating electric field are absorbed or emitted with the photon associated with an electronic transition. This multiphoton process leads to the formation of satellites in the spectrum at integer multiples of the frequency associated with the dynamic electric field. Utilizing the dynamic Stark effect the time varying electric field in a driven plasma sheath can be determined from the time-averaged and phase resolved emission spectra. Currently two methods are used to calculate the emission spectrum associated with an atomic system in the presence of a dynamic electric field: the quasi-static method and the Floquet method. The quasi-static method assumes that time varying field varies slowly enough that DC Stark effect theory can be used to generate integrated Stark profiles over the period of a time varying field. The Floquet method treats the dynamic multi-photon process and presents a more accurate treatment of the Stark profile dependence on transient field characteristics, particularly at higher frequencies. The methodology and applicability of the quasi-static and Floquet methods will be discussed with respect to sheaths driven in the RF range of frequencies. This work presents experimental measurements of line profiles in the RF sheath for both hydrogen and helium discharges in the presence of a DC magnetic field. The RF sheath electric field parameters are determined utilizing a generalized dynamic Stark effect model and a novel line shape analysis package. [ABSTRACT FROM PUBLISHER]