High-precision measurement of ^235U ground-state hyperfine structure by laser-rf double resonance

The laser-rf double-resonance technique has been used to make precise (±1-kHz) measurements of four hyperfine intervals in the atomic ground state of 235U. It is found that A = −60.559 ± 0.003 MHz and B = 4104.15 ± 0.20 MHz, uncorrected for second-order effects.