Development of laser-induced breakdown spectroscopy (LIBS) with timed ablation to improve detection efficiency

Figures & data

Figure 1. A schematic of experiment setup including a top view of an aerosol chamber and a trigger/pulse timing diagram.

Table 1. A summary of parameters used for the triggering LIBS system.

Parameters	values
Aerosol air velocity	8 m/s
Sheath air velocity	40 m/s
Q-switch delay time (μs)	200
Spectrometer gate delay time (μs)	1
PMT supply voltage and threshold voltage (volt)	0.2–0.3
Distance between nozzle tip and scattering laser (mm)	2
Distance between nozzle tip and pulse laser (mm)	5

Figure 2. LIBS spectra for particles (NaCl, MgCl₂, KCl, and CaCl₂) with different values of the pulse laser energy under the free-firing laser condition (1 Hz).

Figure 3. (a) Hitting efficiency of particles (350 nm CaCl₂ particles), and (b) peak area of Ca in LIBS spectra with varying number concentrations under the free-firing laser condition (1 Hz).

Figure 4. Comparison of hitting efficiency (%) and hitting rate of CaCl₂ particles under free firing laser conditions (1 Hz versus 5 Hz) with varying number concentrations.

Figure 5. Hitting efficiency of 350 nm CaCl₂ particles with different flash lamp delay times under the triggering laser condition.

Figure 6. Comparison of (a) hitting efficiency and (b) hitting rate of 350 nm CaCl₂ particles between the trigger laser and free-firing laser conditions with varying number concentrations.