Spontaneous Ultraviolet Emission from {sup 233}Uranium/T229ho rium Samples

The spontaneous ultraviolet luminescence reported [G.thinspM. Irwin and K.thinspH. Kim, Phys.thinspthinspRev.thinspthinspLett.thinspthinsp{bold 79}, 990 (1997); D.thinspS. Richardson {ital etthinspthinspal., ibid.}thinspthinsp{bold 80}, 3206 (1998)] from {sup 233}uranium compounds and ascribed to an ultraviolet gamma-ray emission from the metastable {sup 229}thorium daughter is actually N{sub 2} discharge emission induced in the air surrounding the sample by the sample radioactivity. The UV spectrum from high elemental and isotopic purity {sup 233}UO{sub 3} reported here also exhibits a line at 391.3thinspthinspnm that does not appear to be due to electric discharge N{sub 2} emission. {copyright} {ital 1999} {ital The American Physical Society}