Resonance and Nonresonant Laser Ionization of Sputtered Uranium Atoms from Thin Films and Single Microparticles: Evaluation of a Combined System for Particle Trace Analysis Export

@article{citeulike:1538340, abstract = {Abstract: The resonance and nonresonant laser ionization of uranium atoms sputtered from thin metal films and individual micrometer-size uranium oxide particles, respectively, was studied to evaluate a new setup for the analysis of actinide-containing micrometer-size particles. Experiments using nonresonant (193-nm) ionization of atoms and molecules sputtered from micrometer-size uranium oxide particles have shown that the uranium detection efficiencies for sputtered neutral atoms are \~{}2 orders of magnitude higher than for secondary ions. In uranium particles of 0.5-m diameter, 6 × 106 atoms of 235U were easily detected and the isotopic ratio of 235U/238U = 0.0048 ± 4.6\% is in excellent agreement with the certified value. The use of two-color, two-step resonance ionization of the sputtered neutral uranium atoms from thin films was investigated. Several excitation schemes were tested, and a significant population of several low-lying metastable states after ion sputtering was observed. Autoionizing states for double-resonant ionization were determined, and the high selectivity of ionization schemes involving these autoionizing states was illustrated by comparing the flight-time distributions of different sputtered species obtained both by resonance and nonresonant multiphoton (355-nm) laser postionization. Ideally, the options for resonance as well as nonresonant ionization would be combined in a single setup, to obtain a large gain in sensitivity and selectivity. Thus, information about the main components as well as specific isotopic information of a trace element could be obtained from the same single particle.}, address = {Institute for Environment and Sustainability, European Commission Joint Research Center, T.P. 290, I-21020 Ispra (VA), Italy, Institute for Transuranium Elements, European Commission Joint Research Center, Postfach 2340, D-76125 Karlsruhe, Germany, Physikalisches Institut, Westf\"{a}lische Wilhelms-Universit\"{a}t M\"{u}nster, Wilhelm-Klemm-Strasse 10, D-48149 M\"{u}nster, Germany, Institut f\"{u}r Kernchemie, Johannes Gutenberg-Universit\"{a}t Mainz, D-55099 Mainz, Germany, and Laboratorium voor Vaste-Stoffysica en Magnetisme, Katholieke Universiteit Leuven, Celestijnenlaan 200D, B-3001 Leuven, Belgium}, author = {Erdmann, N. and Betti, M. and Kollmer, F. and Benninghoven, A. and Gruning, C. and Philipsen, V. and Lievens, P. and Silverans, R. E. and Vandeweert, E.}, citeulike-article-id = {1538340}, citeulike-linkout-0 = {http://dx.doi.org/10.1021/ac0264426}, citeulike-linkout-1 = {http://pubs.acs.org/doi/abs/10.1021/ac0264426}, day = {1}, doi = {10.1021/ac0264426}, journal = {Anal. Chem.}, keywords = {laser, sims, snms, tof}, month = {July}, number = {13}, pages = {3175--3181}, posted-at = {2007-08-06 16:23:17}, priority = {2}, title = {Resonance and Nonresonant Laser Ionization of Sputtered Uranium Atoms from Thin Films and Single Microparticles: Evaluation of a Combined System for Particle Trace Analysis}, url = {http://dx.doi.org/10.1021/ac0264426}, volume = {75}, year = {2003} }

TY - JOUR ID - citeulike:1538340 L3 - citeulike-article-id:1538340 N2 - Abstract: The resonance and nonresonant laser ionization of uranium atoms sputtered from thin metal films and individual micrometer-size uranium oxide particles, respectively, was studied to evaluate a new setup for the analysis of actinide-containing micrometer-size particles. Experiments using nonresonant (193-nm) ionization of atoms and molecules sputtered from micrometer-size uranium oxide particles have shown that the uranium detection efficiencies for sputtered neutral atoms are ~2 orders of magnitude higher than for secondary ions. In uranium particles of 0.5-m diameter, 6 × 106 atoms of 235U were easily detected and the isotopic ratio of 235U/238U = 0.0048 ± 4.6% is in excellent agreement with the certified value. The use of two-color, two-step resonance ionization of the sputtered neutral uranium atoms from thin films was investigated. Several excitation schemes were tested, and a significant population of several low-lying metastable states after ion sputtering was observed. Autoionizing states for double-resonant ionization were determined, and the high selectivity of ionization schemes involving these autoionizing states was illustrated by comparing the flight-time distributions of different sputtered species obtained both by resonance and nonresonant multiphoton (355-nm) laser postionization. Ideally, the options for resonance as well as nonresonant ionization would be combined in a single setup, to obtain a large gain in sensitivity and selectivity. Thus, information about the main components as well as specific isotopic information of a trace element could be obtained from the same single particle. IS - 13 JF - Anal. Chem. AD - Institute for Environment and Sustainability, European Commission Joint Research Center, T.P. 290, I-21020 Ispra (VA), Italy, Institute for Transuranium Elements, European Commission Joint Research Center, Postfach 2340, D-76125 Karlsruhe, Germany, Physikalisches Institut, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Strasse 10, D-48149 Münster, Germany, Institut für Kernchemie, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany, and Laboratorium voor Vaste-Stoffysica en Magnetisme, Katholieke Universiteit Leuven, Celestijnenlaan 200D, B-3001 Leuven, Belgium EP - 3181 TI - Resonance and Nonresonant Laser Ionization of Sputtered Uranium Atoms from Thin Films and Single Microparticles: Evaluation of a Combined System for Particle Trace Analysis VL - 75 SP - 3175 KW - laser KW - sims KW - snms KW - tof AU - Erdmann, N AU - Betti, M AU - Kollmer, F AU - Benninghoven, A AU - Gruning, C AU - Philipsen, V AU - Lievens, P AU - Silverans, RE AU - Vandeweert, E PY - 2003/07/01/ UR - http://dx.doi.org/10.1021/ac0264426 ER -