An investigation of X-irradiated KCl:H and NaCl:H

Abstract

The e.p.r. spectrum of a new hydrogen atom centre called the U 3 centre has been observed after X-irradiation of KC1 :H crystals at low temperatures and has been assigned to hydrogen atoms in chlorine sites. The centre bleaches thermally at 145 °K with an activation energy of 043 ± 0.03 eV. Optical bleaching experiments indicate that the centre has a weak absorption band peaking at 2-9 eV. The centre cannot be produced by ultraviolet irradiation. A production mechanism involving V k centres is proposed and is discussed in detail. The U 3 centre has also been observed in NaCl:H.