E2 and E4 deformations in 232Th and 239,240,242Pu

High-resolution laser spectroscopy of long-lived plutonium isotopes

“…9. The extracted values for δ r 2 240,A from the optical isotope shifts in this work are consistent with those from muonic x-ray measurements [40]; however, they have uncertainties approximately one order of magnitude smaller when only comparing statistical uncertainties. A comparison of δ r 2 240,A with respect to the average change in meansquared charge radius per isotope is provided in the bottom panel of Fig.…”

“…As expected for heavy elements, the y axis intercepts related to the mass shifts M are small, −232(86) and −701(151) MHz, respectively. Absolute charge radii for 239,240,242 Pu have been determined from x-ray studies of muonic atoms [40]. Plotting the modified isotope shifts δν 240,A against the changes in mean-squared charge radii δ r 2 240,A allows for a direct evaluation of the atomic factors (see Fig.…”

Spectroscopy at the high-energy electron beam ion trap (Super EBIT)

“…The average value which can be derived for 6(r2)2331238 is -0.457(43) fm2. This result can be compared with that of previous studies: neutral-atom optical isotope shift measurements obtaining a value of -0.383(44) fm2[37, 381, and muonic-atom x-ray observations achieving -0.520(81) fm2 for the variation of the mean-square nuclear charge radius [31]. The SuperEBIT measurement, thus, favors neither of the earlier measurements.…”

S-matrix calculations of energy levels of the lithium isoelectronic sequence

“…Also shown are the RMBPT energies of Blundell [25] which include some recoil corrections, and the structure energies of RCI [30] and uranium (Z = 92) which are derived from measurements [18,19], recent works of the St.…”

“…Here g(r) and f (r) are the upper and lower components of Dirac wave functions selfconsistently determined, v is the 2s valence electron, and Z nuc (r) accounts for the finite size of the nucleus using a Fermi distribution with parameters taken from [17], except for thorium and uranium where the c parameters are changed from 6.9264 and 6.9868 fm in [17] to 7.0598 and 7.13753 fm as deduced from measurements [18,19]. A related potential that will arise in the treatment of screening of the Lamb shift is the core-Hartree (CH) potential defined by…”