Using LIBS method in Safeguards

Transcription

1 Éva Kovács-Széles, István Almási, Gábor Galbács INTRODUCTION Laser-Induced Breakdown Spectroscopy (LIBS) is a type of atomic emission spectroscopic technique which is capable to detect almost all the elements from the periodic table in different sample types (solid, liquid or gas). Other advantage of the technique is that a LIBS analysis is much faster than a conventional laboratory technique. Beside the easy usability and fastness of the system the main advantages of the technique is that portable systems are also available. Using a so-called backpack version in-field analysis can be carried out. Therefore, LIBS is a more and more popular technique also e.g. in the nuclear analytics due to its several advantages. It is also tested for Safeguards purposes as a novel technology.

2 Éva Kovács-Széles, István Almási, Gábor Galbács INTRODUCTION In this work development and test of a portable LIBS system is discussed in detail. Detector system with higher resolution and specific software for evaluation of uranium isotope composition has been developed. Different kind of uranium fuel pellets with various enrichments was analyzed as test samples. Concerning the test measurements the developed LIBS instrument was found well-applicable for analysis of Safeguards samples and determination of higher enrichment of uranium in-field. The method is rapid and simple enough for short in-field sample analysis.

3 Éva Kovács-Széles, István Almási, Gábor Galbács INSTRUMENT Portable LIBS system of MTA EK: Type: LIBSCAN5+, portable LIBS system (Applied Photonics Ltd., Anglia) Detector: nm and nm, resolution: 0.08 nm Laser: Nd:YAG, 50 mj 064 nm, 5 ns impulse lenght, Hz Software: UScout (development of MTA EK) 3

4 Éva Kovács-Széles, István Almási, Gábor Galbács SAMPLES Analyzed Samples: (In closed metal sample holders (boxes) covered by glass) Natural Uranium pellet (NU) Low Enriched Uranium pellet (LEU) Uranium Ore Concentrate (yellow cake, YC) Highly Enriched Uranium pellet (HEU) Uranium Ore samples (ORE) Control (stone) 4

5 Éva Kovács-Széles, István Almási, Gábor Galbács RESULTS Analysis of LEU pellets and the characteristic U-lines different particles of the LEU pellet were used 5

6 Éva Kovács-Széles, István Almási, Gábor Galbács RESULTS U peaks in the samples 5000 U(II) 4500 I n t e n s i t y 4000 U(II) YC - control - LEU - NU - U ORE - U ORE - U ORE3 - U ORE Wavelength (nm) Uranium peaks in various samples 6

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8 Éva Kovács-Széles, István Almási, Gábor Galbács RESULTS Calculation of U isotopic compostion by the U-Scout software 8

9 Éva Kovács-Széles, István Almási, Gábor Galbács CONCLUSION In this work different uranium containing materials were analyzed using a portable LIBS system. Dominant features of the emission spectrum in complex sample matrixes were studied and attempts were made for the estimation of the isotopic composition of the samples. LIBS was found capable for analysis of uranium containing materials as a first scanning and characterization of e.g. nuclear materials of unknown origin. Using high enough resolution the technique is also capable for determination of enrichment of uranium. Further investigations are in progress in the field. Acknowledgements: This study was supported by the Hungarian Atomic Energy Authority. 9