Performance degradation of ferrofluidic feedthroughs in a mixed irradiation field

Nikolaos Simos, S. Fernandes, Wolfgang Mittig, Frederique Pellemoine, M. Avilov, M. Kostin, L. Mausner, R. Ronningen, M. Schein, G. Bollen

    Research output: Research - peer-reviewArticle

    Abstract

    Ferrofluidic feedthrough (FF) rotary seals containing either NdFeB or SmCo-type permanent magnets have been considered for use in the target and beam dump systems of the Facility for Rare Isotope Beams (FRIB). To evaluate their performance under irradiation three FF seals were irradiated in a mixed field consisting of fast neutrons, protons and γ-rays to an average absorbed dose of 0.2, 2.0, and 20.0 MGy at the Brookhaven Linac Isotope Producer facility (BLIP). The radiation types and energy profiles mimic those expected at the FRIB facility. Degradation of the operational performance of these devices due to irradiation is expected to be the result of the de-magnetization of the permanent magnets contained within the seal and the changes in the ferrofluid properties. Post-irradiation performance was evaluated by determining the ferrofluidic seal vacuum tightness and torque under static and dynamic conditions. The study revealed that the ferrofluidic feedthrough seal irradiated to a dose of 0.2 MGy maintained its vacuum tightness under both static and rotational condition while the one irradiated to a dose of 2.0 MGy exhibited signs of ferrofluid damage but no overall performance loss. At 20 MGy dose the effects of irradiation on the ferrofluid properties (viscosity and particle agglomeration) were shown to be severe. Furthermore, limited de-magnetization of the annular shaped Nd2Fe14B and Sm2Co17 magnets located within the irradiated FFs was observed for doses of 0.2 MGy and 20 MGy respectively.

    Profile

    degradation
    dosage
    irradiation
    Seals
    Irradiation
    Degradation
    ferrofluids
    isotopes
    Magnetic fluids
    Isotopes
    tightness
    permanent magnets
    magnetization
    vacuum
    Permanent magnets
    Dosimetry
    Magnetization
    Vacuum
    fast neutrons
    agglomeration

    Keywords

    • De-magnetization
    • Ferrofluidic feedthrough
    • Leak rate
    • Neutron irradiation
    • Performance
    • Radiation damage
    • Rotational torque
    • Static torque

    ASJC Scopus subject areas

    • Nuclear and High Energy Physics
    • Instrumentation

    Cite this

    @article{1aa9f80df1e34e91a4f5cfe2eff242fd,
    title = "Performance degradation of ferrofluidic feedthroughs in a mixed irradiation field",
    abstract = "Ferrofluidic feedthrough (FF) rotary seals containing either NdFeB or SmCo-type permanent magnets have been considered for use in the target and beam dump systems of the Facility for Rare Isotope Beams (FRIB). To evaluate their performance under irradiation three FF seals were irradiated in a mixed field consisting of fast neutrons, protons and γ-rays to an average absorbed dose of 0.2, 2.0, and 20.0 MGy at the Brookhaven Linac Isotope Producer facility (BLIP). The radiation types and energy profiles mimic those expected at the FRIB facility. Degradation of the operational performance of these devices due to irradiation is expected to be the result of the de-magnetization of the permanent magnets contained within the seal and the changes in the ferrofluid properties. Post-irradiation performance was evaluated by determining the ferrofluidic seal vacuum tightness and torque under static and dynamic conditions. The study revealed that the ferrofluidic feedthrough seal irradiated to a dose of 0.2 MGy maintained its vacuum tightness under both static and rotational condition while the one irradiated to a dose of 2.0 MGy exhibited signs of ferrofluid damage but no overall performance loss. At 20 MGy dose the effects of irradiation on the ferrofluid properties (viscosity and particle agglomeration) were shown to be severe. Furthermore, limited de-magnetization of the annular shaped Nd2Fe14B and Sm2Co17 magnets located within the irradiated FFs was observed for doses of 0.2 MGy and 20 MGy respectively.",
    keywords = "De-magnetization, Ferrofluidic feedthrough, Leak rate, Neutron irradiation, Performance, Radiation damage, Rotational torque, Static torque",
    author = "Nikolaos Simos and S. Fernandes and Wolfgang Mittig and Frederique Pellemoine and M. Avilov and M. Kostin and L. Mausner and R. Ronningen and M. Schein and G. Bollen",
    year = "2017",
    month = "1",
    doi = "10.1016/j.nima.2016.10.007",
    volume = "841",
    pages = "144--155",
    journal = "Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment",
    issn = "0168-9002",
    publisher = "Elsevier",

    }

    TY - JOUR

    T1 - Performance degradation of ferrofluidic feedthroughs in a mixed irradiation field

    AU - Simos,Nikolaos

    AU - Fernandes,S.

    AU - Mittig,Wolfgang

    AU - Pellemoine,Frederique

    AU - Avilov,M.

    AU - Kostin,M.

    AU - Mausner,L.

    AU - Ronningen,R.

    AU - Schein,M.

    AU - Bollen,G.

    PY - 2017/1/1

    Y1 - 2017/1/1

    N2 - Ferrofluidic feedthrough (FF) rotary seals containing either NdFeB or SmCo-type permanent magnets have been considered for use in the target and beam dump systems of the Facility for Rare Isotope Beams (FRIB). To evaluate their performance under irradiation three FF seals were irradiated in a mixed field consisting of fast neutrons, protons and γ-rays to an average absorbed dose of 0.2, 2.0, and 20.0 MGy at the Brookhaven Linac Isotope Producer facility (BLIP). The radiation types and energy profiles mimic those expected at the FRIB facility. Degradation of the operational performance of these devices due to irradiation is expected to be the result of the de-magnetization of the permanent magnets contained within the seal and the changes in the ferrofluid properties. Post-irradiation performance was evaluated by determining the ferrofluidic seal vacuum tightness and torque under static and dynamic conditions. The study revealed that the ferrofluidic feedthrough seal irradiated to a dose of 0.2 MGy maintained its vacuum tightness under both static and rotational condition while the one irradiated to a dose of 2.0 MGy exhibited signs of ferrofluid damage but no overall performance loss. At 20 MGy dose the effects of irradiation on the ferrofluid properties (viscosity and particle agglomeration) were shown to be severe. Furthermore, limited de-magnetization of the annular shaped Nd2Fe14B and Sm2Co17 magnets located within the irradiated FFs was observed for doses of 0.2 MGy and 20 MGy respectively.

    AB - Ferrofluidic feedthrough (FF) rotary seals containing either NdFeB or SmCo-type permanent magnets have been considered for use in the target and beam dump systems of the Facility for Rare Isotope Beams (FRIB). To evaluate their performance under irradiation three FF seals were irradiated in a mixed field consisting of fast neutrons, protons and γ-rays to an average absorbed dose of 0.2, 2.0, and 20.0 MGy at the Brookhaven Linac Isotope Producer facility (BLIP). The radiation types and energy profiles mimic those expected at the FRIB facility. Degradation of the operational performance of these devices due to irradiation is expected to be the result of the de-magnetization of the permanent magnets contained within the seal and the changes in the ferrofluid properties. Post-irradiation performance was evaluated by determining the ferrofluidic seal vacuum tightness and torque under static and dynamic conditions. The study revealed that the ferrofluidic feedthrough seal irradiated to a dose of 0.2 MGy maintained its vacuum tightness under both static and rotational condition while the one irradiated to a dose of 2.0 MGy exhibited signs of ferrofluid damage but no overall performance loss. At 20 MGy dose the effects of irradiation on the ferrofluid properties (viscosity and particle agglomeration) were shown to be severe. Furthermore, limited de-magnetization of the annular shaped Nd2Fe14B and Sm2Co17 magnets located within the irradiated FFs was observed for doses of 0.2 MGy and 20 MGy respectively.

    KW - De-magnetization

    KW - Ferrofluidic feedthrough

    KW - Leak rate

    KW - Neutron irradiation

    KW - Performance

    KW - Radiation damage

    KW - Rotational torque

    KW - Static torque

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    U2 - 10.1016/j.nima.2016.10.007

    DO - 10.1016/j.nima.2016.10.007

    M3 - Article

    VL - 841

    SP - 144

    EP - 155

    JO - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment

    T2 - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment

    JF - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment

    SN - 0168-9002

    ER -