Overview
RAD instrument utilizes transmission of neutrons or X-rays to obtain visual information on the structure and/or inner processes of a given object. Neutrons are able to pierce through several cm thick materials, so the inner structure of even a bulky object can be characterized in a non-destructive way. The interactions between the neutrons and the matter, however, result in the attenuation of the transmitted neutron beam so giving contrast on a sensitive screen. The image detection of the RAD station comprises digital imaging equipments being able to carry out 2D and 3D imaging using suitable scintillation screens. The dynamic radiography is performed by means of a low-light-level TV camera with a fast imaging cycle, making possible real-time imaging.
Technical details
The RAD neutron imaging facility is served by an in-pile, Cd-covered pin-hole-type collimator for neutron radiation. The measurement positions can be used for dynamic (DNR) and for static (SNR) imaging with a max. beam diameter of ~200 mm. The thermal-equivalent flux at target positions is around 4Å~107 cm-2s-1. The measured L/D ratio is ~250. The scintillation screens for neutron radiography have spatial resolutions between 70-250 μm; while the intensifying screens for X-ray radiography are with a spatial resolution of 100-200 μm. For better flexibility, there is a possibility to apply larger or smaller fields of views (FOV). There is a possibility to use beam filters made of boron-containing rubber and lead bricks, giving a fast/thermal neutron flux ratio of 77 instead of 0.6. Moreover, a sapphire-crystal filter is available to suppress fast neutrons, giving a fast/thermal neutron flux ratio of 0.029. The RAD facility is also equipped with an optional X-ray tube with a max. voltage of 300 kV, allowing dual-modality imaging. Two motorized sample stages, one for small and one for large samples (with a maximum load up to 250 kg) are available to support the investigated objects.
Further readings
- Kis Z, Szentmiklósi L, Belgya T, Balaskó M, Horváth LZ, Maróti B. (2015) Neutron based imaging and element-mapping at the Budapest Neutron Centre, Physics Procedia. 69 (2015) 40 – 47.