The Versatile Neutron Imaging Instrument at SNS
The Oak Ridge National Laboratory has the opportunity to build a world‐class neutron imaging instrument (VENUS) that will uniquely utilize the Spallation Neutron Source (SNS) to measure and characterize large‐scale and complex systems for the EERE, BES, BER and NIH programs. VENUS will provide academia, industry and government laboratories with the opportunity to advance research in energy materials and processes, materials science, additive manufacturing, mechanical and physical behavior, geosciences and petroleum applications, transportation research, building technologies, plant physiology, biology, archeology, and a range of other areas.
As its name indicates, VENUS is designed to be as versatile as possible to encompass the largest range of applications, while being fully optimized to benefit from the unique capabilities of SNS.
The range of cold to epithermal neutrons at SNS will give users of VENUS access to novel imaging methods, as well as to significantly improved existing methods. The epithermal flux available at SNS will provide additional possibilities for contrast extension and/or enhancement.
The time-of-flight (TOF) neutrons provided at SNS will offer easy and cost-efficient access to energy-selective imaging, hence making use of neutron scattering Bragg features for improved contrast and identification of phases in an absorption image.
The high peak flux of SNS is useful for stroboscopic imaging of repetitive or cyclic motions and is synchronized to a selected neutron energy range for enhanced image contrast. VENUS will also provide simultaneous x-ray imaging capabilities, as a complementary imaging modality.
The energy, E, or wavelength, l, of the neutrons can be determined by TOF:
Where t is the time of detection, te is the time of emission, and L is the distance between the source and the detector, where the image is formed.
The energy dependence is important because many samples have crystalline components where Bragg scattering can give significant energy-dependent, material-specific variations in attenuation. Microstructures, crystal planes and textures (i.e. grain orientation) can be energy-dependent mapped, along with residual stress (by detection of Bragg shifts). At SNS, all energies are collected at once, reducing acquisition time from several days to a few hours, with the luxury of acquiring neutron data at high TOF resolution. This provides the freedom to later combine, divide, and post-process the data two, three, and four (x, y, z, λ)dimensions.
- Additive Manufacturing
- Grain mapping
- 2D strain mapping
- Porosity, comparison engineering drawings with neutron data, etc.
- Materials chemistry
- Energy storage materials
- Transport and chemical reactions at micro-scale level and associated modeling
- Mechanical and Physical Behavior
- Fracture propagation, failure, deformability under stress
- Magnetic properties
- Geosciences and Plant Physiology
- Fluid flow studies, subsurface reservoirs for hydrocarbon production and CO2 sequestration, petroleum
- Plant/soil interactions
- Transportation Research and Building Technology
- Biological applications