HYPERFINE-STRUCTURE MEASUREMENTS OF HIGH-LYING LEVELS OF URANIUM

A technique for precisely measuring hyperfine structure of any level of neutral uranium which can be excited by a single or multistep transition from the ground or a low-lying-metastable state has been developed. Numerous spectra were measured and fit to obtain precise hyperfine splitting constants. In particular, measurements on the 31869-cm** minus **1 odd level have determined the following: J equals 6, magnetic dipole constant A equals minus 47. 2+360. 6 MHz and electric quadrupole constant B equals 1892+3626 MHz. Structure of serveral excited states of known configuration were measured including the 15632-cm** minus **1 f**2d**2s**2(**5L//7) and the 16930-cm** minus **1 f**3dsp (**7K//5) levels.