Abstract: A compact and small size multichannel collimator for neutrons with energies up to 50 keV is provided. The collimator has a multichannel structure composed of collimating channels (in air, vacuum or in the non-interacting atmosphere of Helium-4) alternating with “full” channels made with absorbent materials for slow neutrons. The geometry of the individual collimating and absorbing channels can be arbitrary. The geometry with channels of square section, such as to create a perfect checkerboard, is preferred from the point of view of ease of construction.

Abstract: SUMMARY The invention relates to a dosimeter (A) wearable by a human subject which includes: at least a first slow neutron sensor S1; a matrix containing a certain amount of absorbent material for slow neutrons; at least a second slow neutron sensor S2; a moderator consisting of or comprising polyethylene, hydrogenated plastic, water, paraffin or other hydrogenated or deuterated compounds.