Technology Transfer Department

Application sectors

Problem to solve

A single spectroscopic technique can supply limited information about surface state and chemical composition. Integration of various techniques into a single instrument, like LIF, Raman and LIBS in the ILS, bring great advantages, particularly in case of rapid and simple switching among the measurement techniques. Measurements at distance could be necessary for safety reasons or because of difficult access to the object. In such cases, the ILS supplies a full solution, including a remote control via WiFi of the instrument. The detection sensitivity strongly depends on the initials projecting of the instrument. In case of ILS, thanks to careful choice of components and ENEA's patented solution, a single high power laser source is used for generating IR laser beam (for LIBS) or UV beam (for LIF and Raman), thus reducing the costs, dimensions and weight, and achieving a very high detection sensitivity

Description

ILS is the only instrument (patented by ENEA) that performs measurements at distance (8-30 m) with multiple techniques: LIF, Laser Scattering (LS), Raman and LIBS. The combination of these techniques supplies information about the state of surface, the molecular and elemental composition. Thanks to a color camera and GUI, the user can explore the scene, select an area to scan and the point density. Fast scanning by LIF/LS (<1 s per point) can identify classes of materials and areas of interest. Raman measurements (~ 10 s per point) can identify molecular composition. LIBS (<1 s per point) detects the elements present on the surface. By applying more laser pulses at a fixed point, also the element distribution in depth is achieved, with spatial resolution in order of 100 nm - 10 µm, dependent on the material. Differently from LIF, LS and Raman, LIBS technique is micro-destructive inside the focal spot; at distance of 10 m, the laser spot has minimum diameter of 1.2 mm. The instrument contains a class IV laser source, it is mounted on a towable cart, and during outdoor campaigns its was used autonomously powered by two generators. The control could be done through remote desktop, thanks to the built-in WiFi. Switching among the measurement techniques is done via GUI, where the positioning of the optical components according to the selected technique and target distance is automatic. For each measurement, the spectra are saved automatically including the timestamp and the relative position on the scanning grid. Presently, the ILS database supports the automatic recognition of explosives and precursors while for the LIBS technique the element identification is implemented. On a 2D map in false colors, overlapped with live image of the target, it is possible to visualize all results of the measurements, as default or selected by user.

Research group involved