Focalizing slow neutron beams at and below micron scales: Discussion on BNCT

GRAPHICAL ABSTRACT ABSTRACT We outline some general properties of slow neutrons and their interactions in material media, their use in Boron Neutron Capture Therapy (BNCT) and their waveguiding properties. We review two important experiments on slow neutron confined propagation: in thin films and in polycapillary glass fibres. Based upon the first experiment and on previous proposals, we formulate two new proposals regarding possibilities for improved focalization (at and a bit below one micron) and propagation along longer lengths (up to about 1 m) with relatively small attenuation, and discuss possible implications for BNCT of small tumours. We emphasize the general interest and possible applications of exploring short scales by means of slow neutrons, through suitable combinations of the devices involved in those two experiments.