New perspectives for neutron imaging through advanced event-mode data acquisition

Abstract

Imaging using scintillators is a widespread and cost-effective approach in radiography. While different types of scintillator and sensor configurations exist, it can be stated that the detection efficiency and resolution of a scintillator-based system strongly depend on the scintillator material and its thickness. Recently developed event-driven detectors are capable of registering spots of light emitted by the scintillator after a particle interaction, allowing to reconstruct the Center-of-Mass of the interaction within the scintillator. This results in a more precise location of the event and therefore provides a pathway to overcome the scintillator thickness limitation and increase the effective spatial resolution of the system. Utilizing this principle, we present a detector capable of Time-of-Flight imaging with an adjustable field-of-view, ad-hoc binning and re-binning of data based on the requirements of the experiment including the possibility of particle discrimination via the analysis of the event shape in space and time. It is considered that this novel concept might replace regular cameras in neutron imaging detectors as it provides superior detection capabilities with the most recent results providing an increase by a factor 3 in image resolution and an increase by up to a factor of 7.5 in signal-to-noise for thermal neutron imaging.

Quantification of Sub-Pixel Dynamics in High-Speed Neutron Imaging

“…Additionally, a new MCP detector currently under development at ORNL based on the Timepix3 readout is expected to improve the overall signal-to-noise ratio by enabling imaging with a high-bandwidth event-based acquisition mode and a data-driven readout [ 31 , 32 ]. This new architecture will also enable event centroiding, which has been shown to achieve a 3× improvement in spatial resolution in both MCP [ 18 ] and scintillator configurations [ 33 ]. By combining the attenuation modeling approach described in this work with the new detector, it may be possible to measure cyclic motions below a 1 μm scale.…”

3D isotope density measurements by energy-resolved neutron imaging

“…A recent development in scintillator-based neutron detection 31 offers new perspectives for the presented technique and could overcome some of the limitations with the detector deployed in this work. This new development provides a neutron counting principle based on a detector that offers a variable field of view (roughly 1 × 1 cm 2 to 20 × 20 cm 2 ) and interchangeable scintillators.…”

“…Furthermore, a major challenge in the presented work was the determination of the background, which is predominantly caused by gamma contributions. Neutron/gamma discrimination enabled by this novel technique would therefore allow to suppress such background 31 . Extending the accessible energy range with an improved background would significantly enlarge the potential applications of the presented technique by allowing to access a larger number of isotopes with resonances at higher neutron energies than presently accessible.…”

Extending MIEZE spectroscopy towards thermal wavelengths

“…Therefore, we have started exploring different detector technologies for the application in MIEZE. One possible candidate would be a scintillation detector based on the Timepix chip, which is currently being tested for neutrons by Losko et al [49].…”