We report on a prototype Laser Induced Breakdown Spectroscopy (LIBS) Deminers' Probe used to identify
underground objects. We have built a prototype, and are in the process of developing a more advanced LIBS
based Deminer' s Probe used to prod objects underground, and then sense them by creating a micro-plasma
plume of the surface material and analyzing the spectrum of the emitted light to identify the object. It is
expected that the Deminer will be able to eliminate many false positives, which consume most of the
SARA Fiber-Optics coupled LIBS system consists in a probe that can be inserted into the ground to provide a
path for both the laser beam to the target, and for the micro-plasma plume fluorescence from the target to a
spectrometer or spectrometers for analysis.
The probe is closely modeled after the conventional Deminers' probe, resembling a saber. We have
demonstrated that this simple system is capable of producing remarkably different spectra from different
materials. Our next steps are to add a number of features to the Deminers' Probe. These include: a new
optical configuration to increase the irradiance and fluence created by the pulsed laser at the target, a multiple
channel fluorescence reception system that can increase the amount of light delivered to the spectrometers, a
fluidic system to clear the detritus away from the probe tip, and a complete operational/control and readout
system for the Deminer to use.
Mine-lane tests are planned to be performed in the later part of 2009, or shortly thereafter.