Resonant- and avalanche-ionization amplification of laser-induced plasma in air
Abstract
Amplification of laser-induced plasma in air is demonstrated utilizing resonant laser ionization and avalanche ionization. Molecular oxygen in air is ionized by a low-energy laser pulse employing (2 + 1) resonance-enhanced multi-photon ionization (REMPI) to generate seed electrons. Subsequent avalanche ionization of molecular oxygen and nitrogen significantly amplifies the laser-induced plasma. In this plasma-amplification effect, three-body attachments to molecular oxygen dominate the electron-generation and -loss processes, while either nitrogen or argon acts as the third body with low electron affinity. Contour maps of the electron density within the plasma obtained in O2/N2 and O2/Ar gas mixtures are provided to show relative degrees of plasma amplification with respect to gas pressure and to verify that the seed electrons generated by O2 2 + 1 REMPI are selectively amplified by avalanche ionization of molecular nitrogen in a relatively low-pressure condition (≤100 Torr). Such plasma amplification occurring in air could be useful in aerospace applications at high altitude.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Oct 14, 2014
- Source ID
- 10.1063/1.4896789
Entities
People
- James. R. Gord
- Naibo Jiang
- Sukesh Roy
- Yue Wu
- Zhili Zhang
Organizations
- Air Force Research Laboratory
- National Science Foundation
- University of Tennessee