Evaluation of laser-induced breakdown spectroscopy analysis potential for addressing radiological threats from a distance

• Distant identification of radioactive surrogates on urban surfaces has been proved.
• LIBS sensitivity to distant detection of radioactive surrogates has been checked.
• Influences of the atmosphere on emission signals have been ascertained.
• Usage of standoff LIBS for identifying forensic evidences has been proved.

Although radioactive materials are nowadays valuable tools in nearly all fields of modern science and technology, the dangers stemming from the uncontrolled use of ionizing radiation are more than evident. Since preparedness is a key issue to face the risks of a radiation dispersal event, development of rapid and efficient monitoring technologies to control the contamination caused by radioactive materials is of crucial interest. Laser-induced breakdown spectroscopy (LIBS) exhibits appealing features for this application. This research focuses on the assessment of LIBS potential for the in-situ fingerprinting and identification of radioactive material surrogates from a safe distance. LIBS selectivity and sensitivity to detect a variety of radioactive surrogates, namely 59Co, 88Sr, 130Ba, 133Cs, 193Ir and 238U, on the surface of common urban materials at a distance of 30 m have been evaluated. The performance of the technique for nuclear forensics has been also studied on different model scenarios. Findings have revealed the difficulties to detect and to identify the analytes depending on the surface being interrogated. However, as demonstrated, LIBS shows potential enough for prompt and accurate gathering of essential evidence at a number of sites after the release, either accidental or intentional, of radioactive material. The capability of standoff analysis confers to LIBS unique advantages in terms of fast and safe inspection of forensic scenarios. The identity of the radioactive surrogates is easily assigned from a distance and the sensitivity to their detection is in the range of a few hundreds of ng per square centimeter.