Trapped-ion technique for measuring the nuclear charge radii of highly charged radioactive isotopes

We present the first measurement to isolate the variation of nuclear effects in the x-ray transitions of few-electron heavy ions. Using a novel technique to produce and trap radioactive ions we measured the energy difference between 2s1/2-2p3/2 transitions in Li-, Be-, B-, and C-like 233U and 238U. We show that because of the simplified atomic structure of few electron ions the data are readily interpreted in terms of the variation in the mean nuclear radius. A value δ left-angle r2 right-angle 233,238=-0.457±0.043 fm2 is found, which lies between earlier measurements based on different techniques. copyright 1996 The American Physical Society