Comparison of LIBS results on ITER-relevant samples obtained by nanosecond and picosecond lasers

Peeter Paris, Jelena Butikova, Matti Laan, Antti Hakola, Indrek Jõgi, Jari Likonen, Eduard Grigore, Cristian Ruset

    Research output: Contribution to journalArticleResearchpeer-review

    Abstract

    ITER foresees applying laser induced breakdown spectroscopy (LIBS) as a tool for quantitative assessment of fuel retention in the first walls. One open problem related to LIBS application is the choice of the laser type. Here we compare two Nd/YAG lasers with different pulse durations, 0.15 and 8 ns, working at λ = 1064 nm for LIBS studies of samples with D-doped W/Al coatings of ≈ 3 μm thickness (Al is used as a proxy of Be) on Mo. Low pressure argon was used as a background gas. Experiments were done in conditions where other factors (broadening of spectral lines, signal-to-noise ratio, limited thickness of coatings etc.) did not shadow the effect of laser pulse duration. For these reasons, low pressure argon was used as the background gas and fluences were kept at comparatively low values. Spectra of laser-produced plasma were recorded as a function of the number of laser pulses.
    Partially overlapping lines of hydrogen isotopes were fitted with Voigt contours, intensities were fitted and depth profiles of deuterium were reconstructed. The relative standard error of curve-fitting of spectra recorded with the laser of shorter pulse duration was two times smaller than that recorded by the longer pulse laser. The electron density was found from the Stark broadening of Hα line of the laser-produced plasma and the electron temperature of plasma was found on the basis W and Mo lines.
    It was found that in the case of ps laser an acceptable accuracy of the detection of deuterium was possible at considerably lower values of fluence. Steps needed for comparison of ps and ns lasers in ITER-relevant conditions were discussed.

    LanguageEnglish
    Pages1-5
    Number of pages5
    JournalNuclear Materials and Energy
    Volume18
    DOIs
    Publication statusPublished - 2019
    MoE publication typeNot Eligible

    Fingerprint

    Laser induced breakdown spectroscopy
    laser-induced breakdown spectroscopy
    Laser pulses
    Lasers
    Laser produced plasmas
    Argon
    Deuterium
    lasers
    pulse duration
    Gases
    laser plasmas
    Coatings
    deuterium
    fluence
    Electron temperature
    low pressure
    Curve fitting
    argon
    Isotopes
    coatings

    Keywords

    • ITER-relevant coatings
    • LIBS diagnostics
    • Detection of hydrogen isotopes
    • Elemental depth profiles
    • Temperature of laser-produced plasma

    OKM Publication Types

    • A1 Refereed journal article

    OKM Open Access Status

    • 1 Open Access

    Cite this

    Paris, Peeter ; Butikova, Jelena ; Laan, Matti ; Hakola, Antti ; Jõgi, Indrek ; Likonen, Jari ; Grigore, Eduard ; Ruset, Cristian. / Comparison of LIBS results on ITER-relevant samples obtained by nanosecond and picosecond lasers. In: Nuclear Materials and Energy. 2019 ; Vol. 18. pp. 1-5.
    @article{dd1c735c03da4136b429bfc273a44b76,
    title = "Comparison of LIBS results on ITER-relevant samples obtained by nanosecond and picosecond lasers",
    abstract = "ITER foresees applying laser induced breakdown spectroscopy (LIBS) as a tool for quantitative assessment of fuel retention in the first walls. One open problem related to LIBS application is the choice of the laser type. Here we compare two Nd/YAG lasers with different pulse durations, 0.15 and 8 ns, working at λ = 1064 nm for LIBS studies of samples with D-doped W/Al coatings of ≈ 3 μm thickness (Al is used as a proxy of Be) on Mo. Low pressure argon was used as a background gas. Experiments were done in conditions where other factors (broadening of spectral lines, signal-to-noise ratio, limited thickness of coatings etc.) did not shadow the effect of laser pulse duration. For these reasons, low pressure argon was used as the background gas and fluences were kept at comparatively low values. Spectra of laser-produced plasma were recorded as a function of the number of laser pulses.Partially overlapping lines of hydrogen isotopes were fitted with Voigt contours, intensities were fitted and depth profiles of deuterium were reconstructed. The relative standard error of curve-fitting of spectra recorded with the laser of shorter pulse duration was two times smaller than that recorded by the longer pulse laser. The electron density was found from the Stark broadening of Hα line of the laser-produced plasma and the electron temperature of plasma was found on the basis W and Mo lines.It was found that in the case of ps laser an acceptable accuracy of the detection of deuterium was possible at considerably lower values of fluence. Steps needed for comparison of ps and ns lasers in ITER-relevant conditions were discussed.",
    keywords = "ITER-relevant coatings, LIBS diagnostics, Detection of hydrogen isotopes, Elemental depth profiles, Temperature of laser-produced plasma",
    author = "Peeter Paris and Jelena Butikova and Matti Laan and Antti Hakola and Indrek J{\~o}gi and Jari Likonen and Eduard Grigore and Cristian Ruset",
    year = "2019",
    doi = "10.1016/j.nme.2018.11.018",
    language = "English",
    volume = "18",
    pages = "1--5",
    journal = "Nuclear Materials and Energy",
    issn = "2352-1791",
    publisher = "Elsevier",

    }

    Comparison of LIBS results on ITER-relevant samples obtained by nanosecond and picosecond lasers. / Paris, Peeter; Butikova, Jelena; Laan, Matti; Hakola, Antti; Jõgi, Indrek; Likonen, Jari; Grigore, Eduard; Ruset, Cristian.

    In: Nuclear Materials and Energy, Vol. 18, 2019, p. 1-5.

    Research output: Contribution to journalArticleResearchpeer-review

    TY - JOUR

    T1 - Comparison of LIBS results on ITER-relevant samples obtained by nanosecond and picosecond lasers

    AU - Paris, Peeter

    AU - Butikova, Jelena

    AU - Laan, Matti

    AU - Hakola, Antti

    AU - Jõgi, Indrek

    AU - Likonen, Jari

    AU - Grigore, Eduard

    AU - Ruset, Cristian

    PY - 2019

    Y1 - 2019

    N2 - ITER foresees applying laser induced breakdown spectroscopy (LIBS) as a tool for quantitative assessment of fuel retention in the first walls. One open problem related to LIBS application is the choice of the laser type. Here we compare two Nd/YAG lasers with different pulse durations, 0.15 and 8 ns, working at λ = 1064 nm for LIBS studies of samples with D-doped W/Al coatings of ≈ 3 μm thickness (Al is used as a proxy of Be) on Mo. Low pressure argon was used as a background gas. Experiments were done in conditions where other factors (broadening of spectral lines, signal-to-noise ratio, limited thickness of coatings etc.) did not shadow the effect of laser pulse duration. For these reasons, low pressure argon was used as the background gas and fluences were kept at comparatively low values. Spectra of laser-produced plasma were recorded as a function of the number of laser pulses.Partially overlapping lines of hydrogen isotopes were fitted with Voigt contours, intensities were fitted and depth profiles of deuterium were reconstructed. The relative standard error of curve-fitting of spectra recorded with the laser of shorter pulse duration was two times smaller than that recorded by the longer pulse laser. The electron density was found from the Stark broadening of Hα line of the laser-produced plasma and the electron temperature of plasma was found on the basis W and Mo lines.It was found that in the case of ps laser an acceptable accuracy of the detection of deuterium was possible at considerably lower values of fluence. Steps needed for comparison of ps and ns lasers in ITER-relevant conditions were discussed.

    AB - ITER foresees applying laser induced breakdown spectroscopy (LIBS) as a tool for quantitative assessment of fuel retention in the first walls. One open problem related to LIBS application is the choice of the laser type. Here we compare two Nd/YAG lasers with different pulse durations, 0.15 and 8 ns, working at λ = 1064 nm for LIBS studies of samples with D-doped W/Al coatings of ≈ 3 μm thickness (Al is used as a proxy of Be) on Mo. Low pressure argon was used as a background gas. Experiments were done in conditions where other factors (broadening of spectral lines, signal-to-noise ratio, limited thickness of coatings etc.) did not shadow the effect of laser pulse duration. For these reasons, low pressure argon was used as the background gas and fluences were kept at comparatively low values. Spectra of laser-produced plasma were recorded as a function of the number of laser pulses.Partially overlapping lines of hydrogen isotopes were fitted with Voigt contours, intensities were fitted and depth profiles of deuterium were reconstructed. The relative standard error of curve-fitting of spectra recorded with the laser of shorter pulse duration was two times smaller than that recorded by the longer pulse laser. The electron density was found from the Stark broadening of Hα line of the laser-produced plasma and the electron temperature of plasma was found on the basis W and Mo lines.It was found that in the case of ps laser an acceptable accuracy of the detection of deuterium was possible at considerably lower values of fluence. Steps needed for comparison of ps and ns lasers in ITER-relevant conditions were discussed.

    KW - ITER-relevant coatings

    KW - LIBS diagnostics

    KW - Detection of hydrogen isotopes

    KW - Elemental depth profiles

    KW - Temperature of laser-produced plasma

    U2 - 10.1016/j.nme.2018.11.018

    DO - 10.1016/j.nme.2018.11.018

    M3 - Article

    VL - 18

    SP - 1

    EP - 5

    JO - Nuclear Materials and Energy

    T2 - Nuclear Materials and Energy

    JF - Nuclear Materials and Energy

    SN - 2352-1791

    ER -