Relative spectral response calibration using Ti plasma lines

Abstract

This work introduces the branching ratio (BR) method for determining relative spectral responses, which are needed routinely in laser induced breakdown spectroscopy (LIBS). Neutral and singly ionized Ti lines in the 250-498 nm spectral range are investigated by measuring laser-induced micro plasma near a Ti plate and used to calculate the relative spectral response of an entire LIBS detection system. The results are compared with those of the conventional relative spectral response calibration method using a tungsten halogen lamp, and certain lines available for the BR method are selected. The study supports the common manner of using BRs to calibrate the detection system in LIBS setups.

Emission spectroscopic diagnostics of weakly ionized argon-diluted plasmas: glow discharge and inductively coupled plasma

“…Radiometric calibration of the instrument, providing spectral response as a function of the wavelength, was performed using standard lamps, a tungsten-halogen lamp and a deuterium lamp, with known spectral radiance, and by the branching ratio method [24] with different Fe I, Fe II and Ar I line pairs. Calibration in the ICP part of this study was made by the branching ratio method only, based on Fe I, Fe II, Ti I, Ar I, Ar II line pairs [25][26][27]. A more detailed description of the spectral measurements can be found in our earlier papers concerning the spectra of individual elements [19,20,28,29,45].…”

A Review of Development in the Research of Self-Absorption on Laser-Induced Breakdown Spectroscopy

“…Branching ratio (BR). In 2018, Fei et al 52 utilized the BR method to discern the non-self-absorbed lines in calibration-free laser- induced breakdown spectroscopy (CF-LIBS). The BR parameter is determined by the ratio of the intensities of two lines, denoted as 𝐼 1 and 𝐼 2 , that stem from a common upper energy level.…”

“…Following the application of this method for selecting CF-LIBS lines, it was observed that the error for the primary element Ni in the nickel-base alloy varied between 0.04% and 19.03%. Fei et al 52 determined that the Ti I and Ti II spectral lines of LIBS could be corrected using BR by optimizing the laser energy and delay time. In 2021, Medina et al 54 utilized the BR approach to evaluate optically thin conditions in LIBS, in conjunction with the principles of the Self-Absorption-Free LIBS (SAF-LIBS) technique.…”