The Effect of Torch Pressure on Analyte Response in a 27 MHz Inductively Coupled Plasma
Abstract
Recent studies employing an inductively coupled argon plasma system equipped with a torch capable of operating at pressures between 100 torr and 3000 torr will be described. Results from these studies indicate two major areas of research where non-atmospheric pressure torch conditions can be utilized. The first of these areas is the elucidation of excitation and energy transfer mechanisms within the plasma. The effect of pressure on energy transfer mechanisms, electron densities and other excitation phenomenon will be discussed and evaluated in light of recent plasma models. Data demonstrating shifts in the relative concentrations of excited state and ground state species will be presented along with spacial mapping of excitation temperatures and ion-to-atom ratios within the plasma. Additional data to be presented will include relative emission intensities for atomic and ionic emissions originating from high and low energy transitions. Such data is important in predicting plasma deviation from local thermal equilibrium conditions. Results of studies indicating a shift of plasma conditions toward local thermal equilibrium with increasing pressure and the implications for theoretical modeling of this trend will also be discussed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 04, 1988
- Accession Number
- ADA198595
Entities
People
- M. Bonner Denton
- Thomas R. Smith
Organizations
- University of Arizona