MAUD - SANS Diffractometer

High-resolution SANS diffractometer is one of two experimental facilities operated at the neutron channel HK8. The double-bent-crystal SANS diffractometer MAUD is designed for the measurements of neutron small-angle scattering in the high Q-resolution mode. In contrast to the conventional double-crystal arrangements, the fully asymmetric diffraction geometry on the elastically bent Si analyzer is employed inorder to transfer the angular distribution of the scattered neutrons to the spatial distribution. It enables then to analyze the whole scattering curve by a one-dimensional position sensitive detector.

The instrument is mainly suited to investigation of structural or compositional inhomogeneities in materials in the size range 0.05÷2 micrometer, mainly porous materials and large precipitates in alloys.

  • MAUD description

    The double-crystal diffractometer MAUD (formerly DN-2) is designed for the measurements of neutron small-angle scattering in the high Q-resolution mode. In contrast to conventional double-crystal arrangements (step-by-step angular scanning), a fully asymmetric diffraction geometry on the elastically bent Si analyzer is employed to transfer the angular distribution of the scattered neutrons to the spatial distribution at position sensitive detector (PSD) which enables equisition of the whole scattering curve by a one-/two-dimensional PSD. It reduces the exposure time per sample typically to 0.5-5 hours (depending on the particular Q-resolution and sample cross-section).

    P7200101-003

    MAUD is suitable for investigation of inhomogeneities in the size range from 20-50 nm up to several micrometres and is thus complementary to conventional pin-hole SANS facilities (see e.g. SANS I at SINQ) and Bonse-Hart or focusing USANS (e.g. KWS-3 at MLZ).

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  • Instrument Parameters

    Monochromator   bent perfect crystal Si(111), symmetric reflection
    Sample maximum irradiated cross-section 4x25 mm2
    Analyzer bent perfect crystal Si 111, fully asymmetric geometry
    Detector 2-dimensional position sensitive detector, 3He filled, resolution ~ 2 mm
    Wavelength 2.09 Ă
    Neutron flux 5x103 ÷ 5x104 n s-1 cm-2
    Q-resolution 10-4 ÷ 10-3 Ă-1
    Q-range 2x10-4 ÷ 2x10-2Ă-1
    size range 500 Ă - 2 micrometers

     

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  • Sample environment

    To enhance the possibility to measure the samples at various conditions, several sample environments can be put on MAUD beam. For non-ambient condition studies, a vacuum furnace can be used. Samples within a set can be automatically exchanged by sample changer for up to 9 samples or sample changer 2 with 5 positions and temperature regulation (20-900C). For mechanical testing, a deformation rig can be employed with maximum tensile/pressure load up to 20 kN. For measurement of anisotropic samples, a rotation table can be installed. Statical magnetic field can be applied to sample to sample either horizontally or vertically by help of electrical magnet up to 2 Tesla (20000 G).

     

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  • Data treatment software

    A suite of programs suitable to process and analyze SANS data from both double crystal and pin-hole instruments has been developed at NPI. It is available at the SAS data analysis page.

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  • Applying for the beam-time 

    Do not worry - it is easy and quick process! In order to submit experimental proposer please register (or login) to CANAM user office web site. Your proposal will be evaluated by as soon as possible, usually it takes 1-2 weeks. Afterwards you disscuss the convinient dates for the beam-time with the instrumnet responsible. Please note, that there is no any dead-line for proposal submission.

    It is recommended to discuss technical feasibility of the proposed experiment with instrumental responsible (Vasyl Ryukhtin, PhD.) before final submiting.

    Beam time operation of MAUD instrument is supported by project of ministry of Youth and Education and thus it should be mentioned in publications (e.g.: SANS experiment were carried out at the CANAM infrastructure of the NPI CAS Rez supported through MŠMT project No. LM2015056).

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