### Abstract

Nuclear magnetic moments provide a sensitive test of nuclear wave functions, in particular those of neutrons, which are not readily obtainable from other nuclear data. These are taking added importance by recent proposals to study parity non-conservation (PNC) effects in alkali atoms in isotopic series. By taking ratios of the PNC effects in pairs of isotopes, uncertainties in the atomic wave functions are largely cancelled out at the cost of knowledge of the change in the neutron wave function. The Bohr-Weisskopf effect (B-W) in the hyperfine structure interaction of atoms measures the influence of the spatial distribution of the nuclear magnetization, and thereby provides an additional constraint on the determination of the neutron wave function. The added great importance of B-W in the determination of QED effects from the hfs in hydrogen-like ions of heavy elements, as measured recently at GSI, is noted. The B-W experiments require precision measurements of the hfs interactions and, independently, of the nuclear magnetic moments. A novel atomic beam magnetic resonance (ABMR) method, combining rf and laser excitation, has been developed for a systematic study and initially applied to stable isotopes. Difficulties in adapting the experiment to the ISOLDE radioactive ion beam, which have now been surmounted, are discussed. A first radioactive beam measurement for this study, the precision hfs of ^{126}Cs, has been obtained recently. The result is 3629.515(∼0.001) MHz. The ability of ABMR to determine with high precision nuclear magnetic moments in free atoms is a desideratum for the extraction of QED effects from the hfs of the hydrogen-like ions. We also point out manifestations of B-W in condensed matter and atomic physics.

Original language | English (US) |
---|---|

Pages (from-to) | 319-335 |

Number of pages | 17 |

Journal | Hyperfine Interactions |

Volume | 129 |

Issue number | 1-4 |

DOIs | |

State | Published - 2000 |

### Fingerprint

### Keywords

- Bohr-Weisskopf effect
- Hyperfine structure
- Knight shift
- Nuclear magnetic moments
- Parity nonconservation in atomic interactions
- QED

### ASJC Scopus subject areas

- Physics and Astronomy(all)
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics
- Electronic, Optical and Magnetic Materials
- Nuclear and High Energy Physics

### Cite this

*Hyperfine Interactions*,

*129*(1-4), 319-335. https://doi.org/10.1023/A:1012630404421

**Bohr-Weisskopf effect : Influence of the distributed nuclear magnetization on hfs.** / Stroke, H. H.; Duong, H. T.; Pinard, J.

Research output: Contribution to journal › Article

*Hyperfine Interactions*, vol. 129, no. 1-4, pp. 319-335. https://doi.org/10.1023/A:1012630404421

}

TY - JOUR

T1 - Bohr-Weisskopf effect

T2 - Influence of the distributed nuclear magnetization on hfs

AU - Stroke, H. H.

AU - Duong, H. T.

AU - Pinard, J.

PY - 2000

Y1 - 2000

N2 - Nuclear magnetic moments provide a sensitive test of nuclear wave functions, in particular those of neutrons, which are not readily obtainable from other nuclear data. These are taking added importance by recent proposals to study parity non-conservation (PNC) effects in alkali atoms in isotopic series. By taking ratios of the PNC effects in pairs of isotopes, uncertainties in the atomic wave functions are largely cancelled out at the cost of knowledge of the change in the neutron wave function. The Bohr-Weisskopf effect (B-W) in the hyperfine structure interaction of atoms measures the influence of the spatial distribution of the nuclear magnetization, and thereby provides an additional constraint on the determination of the neutron wave function. The added great importance of B-W in the determination of QED effects from the hfs in hydrogen-like ions of heavy elements, as measured recently at GSI, is noted. The B-W experiments require precision measurements of the hfs interactions and, independently, of the nuclear magnetic moments. A novel atomic beam magnetic resonance (ABMR) method, combining rf and laser excitation, has been developed for a systematic study and initially applied to stable isotopes. Difficulties in adapting the experiment to the ISOLDE radioactive ion beam, which have now been surmounted, are discussed. A first radioactive beam measurement for this study, the precision hfs of 126Cs, has been obtained recently. The result is 3629.515(∼0.001) MHz. The ability of ABMR to determine with high precision nuclear magnetic moments in free atoms is a desideratum for the extraction of QED effects from the hfs of the hydrogen-like ions. We also point out manifestations of B-W in condensed matter and atomic physics.

AB - Nuclear magnetic moments provide a sensitive test of nuclear wave functions, in particular those of neutrons, which are not readily obtainable from other nuclear data. These are taking added importance by recent proposals to study parity non-conservation (PNC) effects in alkali atoms in isotopic series. By taking ratios of the PNC effects in pairs of isotopes, uncertainties in the atomic wave functions are largely cancelled out at the cost of knowledge of the change in the neutron wave function. The Bohr-Weisskopf effect (B-W) in the hyperfine structure interaction of atoms measures the influence of the spatial distribution of the nuclear magnetization, and thereby provides an additional constraint on the determination of the neutron wave function. The added great importance of B-W in the determination of QED effects from the hfs in hydrogen-like ions of heavy elements, as measured recently at GSI, is noted. The B-W experiments require precision measurements of the hfs interactions and, independently, of the nuclear magnetic moments. A novel atomic beam magnetic resonance (ABMR) method, combining rf and laser excitation, has been developed for a systematic study and initially applied to stable isotopes. Difficulties in adapting the experiment to the ISOLDE radioactive ion beam, which have now been surmounted, are discussed. A first radioactive beam measurement for this study, the precision hfs of 126Cs, has been obtained recently. The result is 3629.515(∼0.001) MHz. The ability of ABMR to determine with high precision nuclear magnetic moments in free atoms is a desideratum for the extraction of QED effects from the hfs of the hydrogen-like ions. We also point out manifestations of B-W in condensed matter and atomic physics.

KW - Bohr-Weisskopf effect

KW - Hyperfine structure

KW - Knight shift

KW - Nuclear magnetic moments

KW - Parity nonconservation in atomic interactions

KW - QED

UR - http://www.scopus.com/inward/record.url?scp=0034465621&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0034465621&partnerID=8YFLogxK

U2 - 10.1023/A:1012630404421

DO - 10.1023/A:1012630404421

M3 - Article

AN - SCOPUS:0034465621

VL - 129

SP - 319

EP - 335

JO - Hyperfine Interaction

JF - Hyperfine Interaction

SN - 0304-3843

IS - 1-4

ER -