Differential spectrum of the conversion electrons and the excitation energy of (1/2/sup +/)-uranium-235 isomer

The differential spectrum of the conversion electrons of /sup 235m/U has been measured for the first time. The conversion spectrum has been compared with the x-ray electron spectrum of UF/sub 4/ for the case of polycrystalline UF/sub 4/ matrix impregnated with the isomer. On this basis it is concluded that the electrons of the UF/sub 4/ ''valence band,'' 6p/sub 1/2/-, 6p/sub 3/2/-uranium electrons: and possibly 2s-electrons of fluorine: take part in the conversion process. An isomer excitation energy of 76.8 +- 0.5 eV is determined.