Erasure of elementary holograms in LiNbO3:Fe by neutron irradiation

Abstract

Experimental studies on the erasure effect of thermal neutron irradiation on elementary photorefractive hologram in LiNbO3:Fe single crystals are reported. This phenomenon results from the large effective cross-section of 6Li for thermal neutrons and from the large number of the electrons excited to the conduction band by the kinetic energy that is released during the neutron generated α-decay of 6Li nuclei. The excited electrons decrease the electric space-charge field of the previously recorded holographic grating and decrease its diffraction efficiency. The sensitivity threshold of the effect is better than 53 mSv (4×109 cm-2 fluence) at neutron energy of 0. 17 eV. Discussion of potential application ofthe phenomenon is also given.