Temporal variations in the excitation temperature of a laser-induced argon plasma estimated with copper emission lines

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)

Abstract

A time-resolved spectrometric measurement was conducted to determine temporal variations in the excitation temperature within a single laser plume caused by a Nd:YAG laser plasma. The two-line method using copper atomic lines was employed to estimate the excitation temperature. Two line pairs of copper lines: Cu I 521.82/Cu I 510.55 and Cu I 515.32/Cu I 510.55, were measured by using an Echelle spectrograph equipped with an ICCD detector having a high-speed gating. The excitation temperature was gradually elevated with the progress of the plasma expansion. This result cannot be explained from a direct excitation model in which excited species are principally produced through collisions with energetic particles, but from an indirect excitation model in which second-kind collisions with argon metastables and subsequent step-wise de-excitations produce the excited species. In the latter case, high-lying states of copper atoms are more populated compared to the population expected from the Boltzmann distribution. Temporal variations in the emission intensities of copper atomic lines requiring large excitation energies were also measured, and their emissions remained even in the expansion stage of the laser-induced plasma. This result also implies the over-population of highlying copper excited levels. 2009

Original languageEnglish
Pages (from-to)481-485
Number of pages5
Journalanalytical sciences
Volume25
Issue number4
DOIs
Publication statusPublished - 2009 Apr

ASJC Scopus subject areas

  • Analytical Chemistry

Fingerprint Dive into the research topics of 'Temporal variations in the excitation temperature of a laser-induced argon plasma estimated with copper emission lines'. Together they form a unique fingerprint.

Cite this