Contacts
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Instrument Scientist
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Computational Instrument Scientist
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Scientific Associate
Analyzing the structure of inhomogeneities, from minerals to biological tissues.
USANS is designed for the study of hierarchical structures in natural and artificial materials. It can be considered an advanced version of the classical Bonse-Hart double-crystal diffractometer (DCD), which in contrast with its single-wavelength reactor-based analog, will operate with the discrete multiwavelength spectrum of Bragg reflections.
The optical scheme of the USANS instrument is similar to that of the conventional Bonse-Hart DCD; however, the pulsed nature of SNS offers an opportunity to separate the orders of Bragg reflection in time space using the time-of-flight technique. Thus, the application of time-of-flight to the USANS technique allows the separation of data optimized for neutron flux and the Q resolution or minimum accessible Q while simultaneously removing contamination by higher harmonic reflections, one of the most significant contributions to the intrinsic instrument background on this class of instruments.
Ultra-small-angle neutron scattering provides a new way to solve a broad range of scientific problems such as:
Requesting Complementary SANS beam time on a USANS proposal
Beginning with the Spring 2020 call for proposals, users submitting USANS General User proposals may request SANS beam time in order to obtain complementary information on the same sample(s) as for the USANS experiment, with the following conditions:
Moderator | Decoupled poisoned hydrogen |
Source detector distance | 30 m |
Focusing | Copper mosaic Cu (111) crystals |
Monochromator and analyzer | Si (220) channel-cut, triple-bounce crystals |
Bragg angle | 70° |
Wavelength spectrum | 4 Bragg reflections at 3.6, 1.8, 1.2, 0.9 Å |
Q range | 1x10-5 Å-1 < Q < 3x10-3 Å-1 |
Instrument Scientist
Computational Instrument Scientist
Scientific Associate