Precision bond lengths for Rydberg Matter clusters KN (N = 19, 37, 61 and 91) in excitation levels n = 4 - 8 from rotational radio-frequency emission spectra

Clusters of the electronically excited condensed matter Rydberg Matter (RM) are planar and six-fold symmetric with magic numbers N = 7, 19, 37, 61 and 91. The bond distances in the clusters are known with a precision of +- 5% both from theory and Coulomb explosion experiments. Long series of up to 40 consecutive lines from rotational transitions in such clusters are now observed in emission in the radio-frequency range 7-90 MHz. The clusters are produced in five different vacuum chambers equipped with RM emitters. The most prominent series with B = 0.9292 +- 0.0001 MHz agrees accurately with expectation (within 2%) for the planar six-fold symmetric cluster K19 in excitation level n = 4. Other long series agree even better with K19 at n = 5 and 6. The ratio between the interatomic distance and the theoretical electron orbit radius (the dimensional ratio) for K19 in n = 4 is found to be 2.8470 +- 0.0003. For clusters K19 (n = 6) and K37 (n = 7 and 8) the dimensional ratio 2.90 is the highest value that is found, which happens to be exactly the theoretical value. Clusters K61 and K91 in n = 5 and 6 have slightly lower dimensional ratios. This is expected since the edge effects are smaller. Intensity alternations are observed of approximately 7:3. The nuclear spins interact strongly with the magnetic field from the orbiting electrons. Spin transitions are observed with energy differences corresponding accurately (within 0.6%) to transitions with apparent total (delta)F = -3 at excitation levels n = 5 and 6. The angular momentum coupling schemes in the clusters are complex but well understood.Comment: 37 pages, 14 figure

Resonance laser ionization of atoms for nuclear physics

The applications of the laser resonance ionization method in nuclear research are reviewed. Investigation of radioactive isotopes using resonance ionization techniques provides a valuable combination of high selectivity, efficiency and spectral resolution. The majority of radioactive ion beams produced at on-line isotope separator facilities profit from the selectivity and universal applicability of laser ion sources. Numerous ultra-sensitive and high-resolution techniques of laser spectroscopy based on resonance ionization of atoms have been developed for the study of rare and radioactive isotopes. A summary of ionization schemes applied to radioactive isotopes is given in table form. © 2012 The Royal Swedish Academy of Sciences.status: publishe

Nuclear dipole moment of (71)Cu from online beta-NMR measurements

On-line β-NMR measurements on nuclei oriented at low temperatures of the magnetic dipole moment of Cu71(N=42) are reported, with the result μ(Cu71)=+2.28(1) nuclear magneton (n.m.). The value shows a significant difference from μ(Cu67)=+2.54(2) n.m., revealing asymmetry with respect to N=40. This effect presents a challenge to theoretical interpretation. © 2008 The American Physical Society

First On-line beta-NMR on oriented nuclei: magnetic dipole moments of the (nup(1/2))(-1) 1/2(-) ground state in 67Ni and (pip(3/2))(+1) 3/2(-) ground state in 69Cu

The first fully on-line use of the angular distribution of beta emission in detection of NMR of nuclei oriented at low temperatures is reported. The magnetic moments of the single valence particle, intermediate mass, isotopes 67Ni(nup(-1)(1/2);1/2(-)) and 69Cu(pip(1)(3/2);3/2(-)) are measured to be +0.601(5) andmgr;(N) and +2.84(1) andmgr;(N), respectively, revealing only a small deviation from the neutron p(1/2) single-particle value in the former and a large deviation from the proton p(3/2) single-particle value in the latter. Quantitative interpretation is given in terms of core polarization and meson-exchange currents

Coupling a proton and a neutron to the semidoubly magic nucleus Ni-68: A study of Cu-70 via the beta decay of Ni-70 and Cu-70

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Unambiguous identification of three b-decaying isomers in 70Cu

Using resonant laser ionization, beta-decay studies, and for the first time mass measurements, three beta-decaying states have been unambiguously identified in 70Cu. A mass excess of -62 976.1(1.6) keV and a half-life of 44.5(2) s for the (6-) ground state have been determined. The level energies of the (3-) isomer at 101.1(3) keV with T(1/2)=33(2) s and the 1+ isomer at 242.4(3) keV with T(1/2)=6.6(2) s are confirmed by high-precision mass measurements. The low-lying levels of 70Cu populated in the decay of 70Ni and in transfer reactions compare well with large-scale shell-model calculations, and the wave functions appear to be dominated by one proton-one neutron configurations outside the closed Z=28 shell and N=40 subshell. This does not apply to the 1+ state at 1980 keV which exhibits a particular feeding and deexcitation pattern not reproduced by the shell-model calculations.status: publishe