Near-Surface Plasma Formed by Dual-Pulse Laser Action at Two Wavelengths on Titanium in Air

• Published in: Journal of applied spectroscopy Vol. 86; no. 5; pp. 836 - 842
• Main Authors: Chumakov, A. N., Bosak, N. A., Ivanov, A. A.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-11-2019; Springer; Springer Nature B.V
• Subjects: Analysis; Analytical Chemistry; Atomic/Molecular Structure and Spectra; Charged particles; Emission analysis; Harmonic radiation; Lasers; Luminosity; Physics; Physics and Astronomy; Plasma; Plasma physics; Plasma processing; Plasma spectra; Plasma temperature; Plasma torches; Radiation; Spectrum analysis; Titanium; Wavelengths; electron concentration; dual-pulse laser action; laser plasma; specific mass loss; plasma-torch structure; plasma temperature
• ISSN: 0021-9037; 1573-8647
• DOI: 10.1007/s10812-019-00903-4

Spectra and structures of near-surface plasma torches were studied experimentally by measuring the specific mass loss and plume luminosity caused by dual-pulse laser radiation at wavelengths 1064 and 532 nm on titanium in air as functions of the time between laser pulses and their sequence. Dependences of the laser-plasma temperature and concentration of charged particles on the paired laser pulse parameters were established at laser radiation power densities q
1064
≤ 3.1·10
9
and q
532
≤ 2.7·10
9
W/cm
2
for λ = 1064 and 532 nm. The optimal conditions for recording erosion plasma spectra had the initial effect from second-harmonic radiation with a time interval between pulses of 4–5 μs; for specific mass loss, 3–6 μs. The results were important for enhancing the efficiency of laser emission spectral analysis and laser-plasma processing of materials.