Measurements of metastable atom density using energies and densities of energetic "fast" electrons detected in the electron energy distribution function associated with the afterglow plasma produced by a radio frequency inductively coupled plasma helium discharge.

Author

• Jon C. Blessington, West Virginia University

Date of Graduation

2007

Document Type

Thesis

Degree Type

MS

Committee Chair

Mark E. Koepke

Abstract

In this work, electron density, electron temperature, electron energy distribution function (EEDF), and metastable atom density in the afterglow of low-pressure (50 mTorr) helium radio-frequency inductively coupled plasma (RF-ICP) discharges were measured with a Langmuir probe. During the Afterglow period, sufficient time resolution was achieved to quantify the evolution of each quantity. The focus of this work is the investigation of metastable atom densities as inferred by the densities and energies of fast electrons with EEDF peaks corresponding to energies of 14.4eV and 19.8 eV [2]. These peaks arise from electrons produced through Penning ionization [2] with metastable helium atoms and superelastic collisions between metastable atoms and electrons [3]. Through these measurements, it became possible to prove the existence of metastable atoms in the plasma sheath.

Recommended Citation

Blessington, Jon C., "Measurements of metastable atom density using energies and densities of energetic "fast" electrons detected in the electron energy distribution function associated with the afterglow plasma produced by a radio frequency inductively coupled plasma helium discharge." (2007). Graduate Theses, Dissertations, and Problem Reports (ETD). 10962.
https://researchrepository.wvu.edu/etd/10962