Neutron imaging for life science. Recent studies

Recent development of neutron imaging technique applied to life science fields is presented from the view point of fast CT-imaging processes utilizing rapid-rotating sample holder method to prevent radiation damage in the biological sample with the help of sensitive-color image intensifiers having wide-dynamic range to obtain highly-resolved images. By optimizing the scintillation-CCD camera system with shutter speed of 1/10,000 s, the author obtains 3D-mapping of heavy water at varying times after injection of the heavy water as a tracer in plants, such as tomato seedlings and rose-cut flowers, at the neutron-radiography port of JRR-3M (Japanese Research Reactor). Then, the effect of changes in neutron energy for use of neutron-radiography, thermal energy and low-energy, monochromatic and fast neutron energy, is reviewed and their main features are discussed by comparing with each other. Other methods such as MRI and X-ray imaging are also briefly explained. (S. Ohno)