Science and Engineering Associates (SEA) developed a prototype subsurface soil characterization tool for the evaluation of heavy metals. The system, based on Laser-Induced Breakdown Spectroscopy (LIBS), is deployed using a cone penetrometer. The LIBS system consists of a laser source to produce the plasma, a novel hollow waveguide method of delivering the laser source to the subsurface, a small penetrometer probe for focusing the laser light to create a spark and return the light emission for

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... alysis, a spectrometer to spectrally resolve the emission spectrum, an array detector for simultaneous measurements of emission intensities over a range of wavelengths and a computer to conduct equipment control, data acquisition, and data analysis. Under this two phase effort, the system was designed, fabricated and tested, culminating in a successful field demonstration at the DOE Sandia Chemical Waste Landfill for the evaluation of chromium contamination. During this CPT/LIBS test, six penetrations were conducted and the data obtained with the system was used to generate graphs depicting the concentration of chromium as a function of depth to approximately 15 feet, with a range of concentrations from background (≈ 30 ppm) to about 1200 ppm. In addition, prototype LIBS instruments, developed by DOE LANL personnel, were successfully field deployed by SEA at a Formerly Utilized Remedial Action Plan (FUSRAP) site for the detection of beryllium. This 6 week field effort generated a high density surface contour plot of the beryllium concentration over a 40 acre site. Utilizing both van-mounted and backpack systems, SEA evaluated 1664 samples at the site. This was the first full scale field deployment of the portable LIBS instruments and the beryllium concentration data was used successfully for real-time decision-making during the site characterization and for the development of additional plans for subsurface analysis. reduce to elemental form, and become electronically excited. When the input pulse is removed, the excited electrons drop to lower energy levels with the emission of characteristic photon. Elemental analysis is conducted by observation of the wavelength, intensity, and temporal characteristics of the emission lines. A prototype LIBS/CPT was developed and it consists of a Neodymium:Yttrium Aluminum Garnet (Nd:YAG) laser source to produce the plasma, a novel hollow waveguide method of delivering the laser source to the subsurface, a small penetrometer probe for focusing the laser light to create a spark and return the light emission for analysis, a spectrometer to spectrally resolve the emission spectrum, an array detector for simultaneous measurements of emission intensities over a range of wavelengths and a computer to conduct equipment control, data acquisition, and data analysis. In addition to the hardware development, new data analysis techniques that will improve on the quantitative performance of the LIBS system and provide the field operators with more real-time information on the quality of the data for better decision-making in the field. The LIBS/CPT system was designed, fabricated and tested, culminating in a successful field demonstration at the DOE Sandia Chemical Waste Landfill for the evaluation of chromium contamination. During this test, the data obtained with the system was used to generate graphs depicting the concentration of chromium as a function of depth, with a range of concentrations from background (≈ 30 ppm) to about 1200 ppm. In addition, two prototype LIBS systems were successfully field deployed by SEA at a FUSRAP site for the detection of beryllium. This 6 week field effort generated a high density surface contour plot of the beryllium concentration over a 40 acre site ranging from no contamination to over 5000 ppm. This was the first full scale field deployment of the portable LIBS instruments and the LIBS data was used successfully for real-time decision-making during the site characterization and for the development of additional plans for subsurface analysis. contaminated sites in Montana, developing detailed procedures for the fabrication of multi-element calibration soils, evaluated standard laboratory methods for metals analysis, performed an evaluation of the performance of contract labs for metals analysis, and most importantly, led the development of new LIBS spectral data analysis techniques. The details of the EERC effort exceed the scope of this report, but can be obtained by reviewing the EERC DOE summary reports for their Cooperative Research and Development Agreement effort.