Hyperfine structure measurement of the9Be+ 22 s 1/2 ground state by optical pumping

Abstract

Abstract. Thermal 9Be § (I= 3/2) ions are polarized by direct optical pumping in He buffer gas. Observation of AF=-_+1 transitions yields for the hyperfine splitting frequency vhfs(9Be +, l S 2 2s 2S1/2)= 1250018(5)kHz. The result is discussed with regard to predictions of recent theoretical calculations and of the Fermi-Segr6 formula for the ground state hfs of the Li isoelectronic sequence.

Fine and hyperfine structure of the two lowest bound states of Be? and their first two ionization thresholds

“…For Be+ 2S, our results for the single HFS constant are compared with experiment [24] and other correlated results [32]. The result is that the discrepancy between theory and experiment has been greatly reduced.…”

“…Since two of the states (2S, 3P") have been measured [24,25] to high precision, and one (2PO) involves heavy cancellation effects, we will extend our previous treatment [26]. To begin with, we will allow off-diagonal effects between different fine-structure levels of the same configuration to be taken into account, as we have already begun [27] to do.…”

Precision measurement of the nuclear magnetic dipole moment of175Lu by optical pumping of free Lu+ ions

“…* Compare, on the other hand, the accuracy of the Fermi-Segr6 formula in the case of the Li-sequence [4]. ** The deviation of the A factor ratios of 175Lu and 176mLu for the two 2D states indicate a difference in the hfs anomalies for these states of about 4.10 3 [27].…”

“…The method of direct optical pumping of free thermal ions [2][3][4] has been applied to the polarization of several paramagnetic alkaline earth ions. In this paper the extension of the method to 1S o ground state ions is reported for the case of I75Lu+ with nuclear spin I=7/2.…”

A many-body calculation of the hyperfine interaction in the lowest2 S and2 P states of li-like systems

“…Recently, experimental information about the hyperfine interaction of Li-like ions has become available due to new experimental techniques. Weber et al [2] have measured the hyperfine interaction very accurately in the ground state of Be + by means of optical pumping, while Poulsen and Andersen [-3] have used the beam-foil technique to investigate the lowest 2p state of the same ion. No experimental data are available for the ions B2+-O 5+, but Randolph et al [41 have recently measured the hyperfine splitting in the ground state of the F 6 § ion by means of "nuclear quantum beats", using the 197keV state in 19 F as a probe.…”