Laser‐induced Breakdown Spectroscopy

Abstract

ARA is currently developing technologies to improve food safety and food defense preparedness. One technology is Laser-Induced Breakdown Spectroscopy (LIBS), a tool developed by ARA for detecting pathogens in food.

Standoff Detection of Explosives at 1 m using Laser Induced Breakdown Spectroscopy

“…Emissions from CN violet system and C 2 swan bands were observed at 384 nm -389 nm, 516 nm, respectively. CN violet band (1,1), (2,2), (3,3), (4,4) transitions were seen at 387.10 nm, 386.13 nm, 385.42 nm, 385.01 nm, respectively. Table 2 shows relative intensities of the peaks and their corresponding emission wavelengths.…”

“…Under local thermodynamic equilibrium (LTE), the population and depopulation of the atoms in an excited state, are dominated by electron collisions rather than radiative process 2 . The minimum electron density, a necessary but not sufficient condition required to follow LTe is given by McWhirter criterion 35 as -N e (cm -3 ) >1.6 × 10 12 T 1/2 ΔE 3 (5) where ΔE (eV) is the energy difference between spectral line transitions.…”

“…It can provide valuable information about elemental constituents of a sample based on spectral content of the emitted light. Light from a pulsed laser source, of sufficient intensity, when focused onto the sample surface, results in instant thermalisation and evaporation of material and leads to the formation of plasma [1][2][3] . A single laser pulse is sufficient to create a plasma which acts as a rich source of spectral emissions resulting in the LIBS spectrum, typically in the range of 200 nm -900 nm.…”

Comparison of Single Pulse and Double Simultaneous Pulse Laser Induced Breakdown Spectroscopy

“…The emission wavelengths are characteristic of elements and provide information about the sample composition and plasma condition (Cremers and Radziemski 2013). Advantages of LIBS analytical applications are related to laser sampling and the simplicity of the design (J. P. Singh and Thakur 2007), feasibility of producing laser sparks on solids and in gases permits the analysis of a wide range of materials from metals and alloys to fluids and gases (Cremers, Multari, and Knight 2011) and requirement of little or even no sample preparation (J. P. Singh and Thakur 2007). Its applications cover a variety of disciplines such as concentration monitoring (Monfort Guy, Vanderheyden, and Tusset 2012;Palanco, Conesa, and Laserna 2004), heritage processing, art-piece cleaning (Cremers and Chinni 2009;Michel 2010), study of biological samples (V. K. Singh and Rai 2011), and so forth.…”

Analitikai módszerek fejlesztése folyadék és szilárd minták LIBS vizsgálatára

“…"Ujjlenyomatszerű", jellegzetes, összetett minőségi azonosításra alkalmas spektrumokat eredményez a mérés. Terepi mérések megvalósítása is lehetséges kompakt, hordozható kiépítésű LIBS rendszerekkel [28][29][30].…”