Laser Plasma Spectrometry for Hydrogen Mapping

The patent replaces the complex nuclear microprobe system with a laser-based optical emission spectrometry system. Instead of using nuclear reactions and particle beams, the invention uses laser ablation to create plasma and detect optical emissions, thereby substituting a mechanically complex system with a simpler optical system that achieves comparable or superior detection capabilities for hydrogen and oxygen.

The invention changes the detection parameters by using optical emission spectroscopy in the visible and UV ranges instead of nuclear reaction products. By tuning the laser wavelength and detecting specific emission lines (e.g., H-alpha at 656 nm), the system achieves high sensitivity without the complexity of nuclear methods.

The patent replaces electron beam-based detection with laser-induced plasma optical emission detection. This substitution enables the detection of light elements like hydrogen and oxygen by detecting their characteristic optical emissions from plasma, overcoming the fundamental limitation of electron microprobes which cannot detect elements lighter than oxygen due to X-ray absorption.

The invention changes the detection mechanism from X-ray emission (which is absorbed for light elements) to optical emission from plasma (which is detectable for all elements including hydrogen). By detecting atomic emission lines in the optical range, the system achieves both high speed and high sensitivity for light element detection.

The patent replaces the ion bombardment mechanism of SIMS with laser ablation. Instead of using ion beams that physically erode and ionize the surface under vacuum, the invention uses laser pulses to create plasma in ambient atmosphere, detecting optical emissions without significant sample destruction and without vacuum requirements.

The invention operates in ambient atmosphere rather than vacuum, using air or other gases as the environment for plasma formation. This eliminates the need for vacuum systems and makes the technique easier to operate, while the laser-induced plasma provides sufficient sensitivity for trace element detection.

The patent applies local quality by focusing the laser beam to a small spot size on the sample surface, creating a localized plasma region. This focal concentration of energy provides high spatial resolution, allowing elemental analysis at specific locations with micrometer-scale precision while maintaining the operational simplicity of LIBS.

The invention enhances sensitivity by collecting optical emissions from plasma in the vertical dimension using optical fibers or lenses positioned close to the sample surface. This three-dimensional collection approach captures more photons from the plasma, improving detection sensitivity while maintaining ease of operation and spatial resolution.