Multi-mode fiber LIBS detector based on composite constraint enhanced spectrum

Abstract

The invention discloses a multi-mode fiber LIBS detector based on a composite constraint enhanced spectrum. The multi-mode fiber LIBS detector comprises a LIBS probe, a coupling collection system, anda control detection system, wherein the LIBS probe is composed of a fiber coupling head and a focusing chamber; the coupling collection system comprises a dichroscope, a fiber focusing device, and afiber collector; and the control detection system comprises a nanosecond laser, a spectrometer, a programmable pulse delay generator, an ICCD, and a computer. The multi-mode fiber is taken as a transmission medium, laser is focused to the surface of a to-be-measured sample to break induced plasma according to a convex lens imaging rule, and the element spectrum intensity is increased by a composite constraint enhanced plasma radiation method. The detector can realize simultaneous analysis of a plurality of elements, has the advantages of safe and reliable operation, high sensitivity, high measurement precision, high spectral signal-to-noise ratio, low element detecting limit, fast analysis speed, and high efficiency, realizes remote on-line monitoring, and can effectively satisfy the disadvantages of the traditional fiber LIBS detectors.

Description

technical field [0001] The invention belongs to the technical field of laser diagnosis and relates to a multimode optical fiber LIBS detector based on composite confinement enhanced spectrum. Background technique [0002] For the mining operations of phosphate rock and coal ash, the detection of uranium under different geological conditions, the detection of environmental pollutants in water, the analysis of explosion residues, the authenticity of famous paintings, the status of key structures of equipment in industrial fields such as power plant exhaust gas detection Inspection, maintenance and evaluation are important supports for the safety and economy of social industrial production. In order to ensure that there are no harmful defects and damages in the structure of the testing equipment after manufacture and during operation, it is required to carry out in-service and pre-service non-destructive testing, evaluation and effective monitoring during operation of the key c...

AI Technical Summary

Problems solved by technology

First of all, the traditional portable fiber optic LIBS detection system cannot adapt to harsh operating environments such as high radioactivity, high temperature, and high pressure (for example, Huazhong University of Science and Technology, Zeng Xiaoyan, etc., Portable Laser Probe Composition Analyzer Based on Fiber Laser, [P], China, 2013107403189.20151104)

Secondly, the traditional optical fiber LIBS system needs to turn the laser light emitted by the optical fiber into parallel light through a plano-convex lens and then focus it on the surface of the sample to be tested through a plano-convex lens when focusing and breaking down; this collimation and focusing method is complicated, difficult to control, and The spot formed by focusing is larger, and the effect of breakdown is poor

Furthermore, the transmission laser power of the traditional optical fiber LIBS system is small, the transmission efficiency is low, and the spectral signal-to-noise ratio is low, resulting in poor measurement accuracy and low reliability of test results.

At present, there is no online monitoring device or detection equipment that can effectively meet the needs of key equipment detection under harsh working conditions

Images