Search results for "Quadrupole"
showing 10 items of 460 documents
Enhanced Quadrupole and Octupole Strength in Doubly Magic Sn132
2018
The first 2+ and 3- states of the doubly magic nucleus Sn132 are populated via safe Coulomb excitation employing the recently commissioned HIE-ISOLDE accelerator at CERN in conjunction with the highly efficient MINIBALL array. The Sn132 ions are accelerated to an energy of 5.49 MeV/nucleon and impinged on a Pb206 target. Deexciting γ rays from the low-lying excited states of the target and the projectile are recorded in coincidence with scattered particles. The reduced transition strengths are determined for the transitions 0g.s.+→21+, 0g.s.+→31-, and 21+→31- in Sn132. The results on these states provide crucial information on cross-shell configurations which are determined within large-sca…
Quadrupole moment of Fr 203
2017
The spectroscopic electric quadrupole moment of the neutron-deficient francium isotope 203Fr was measured by using high-resolution collinear resonance ionization spectroscopy (CRIS) at the CERN Isotope Separation On-Line Device (ISOLDE)facility. A remeasurement of the 207Fr quadrupole momentwas also performed, resulting in a departure from the established literature value. A sudden increase in magnitude of the 203Fr quadrupole moment, with respect to the general trend in the region, points to an onset of static deformation at N =116 in the 87Fr isotopic chain. Calculation of the static and total deformation parameters show that the increase in static deformation only cannot account for the o…
The REX-ISOLDE project
2002
REX-ISOLDE is a pilot experiment at ISOLDE/CERN to study the structure of neutron-rich nuclei (N=20, N=28) with post-accelerated radioactive ion beams (1). Therefore radioactive ions with charge state 1+, which are delivered by the online mass separator ISOLDE, are accelerated up to 2.2 MeV/u by means of a new concept. The radioactive ions are first accumulated in a Penning trap, then charge breeded to a charge-to-mass ratio of 1/4.5 in an Electron Beam Ion Source (EBIS) and finally accelerated. The LINAC consists of three components, namely a Radio Frequency Quadrupole (RFQ) accelerator, which accelerates the ions from 5 to 300 keV/u, an interdigital H-type structure (IH) with a final ener…
Coulomb Excitation of (142) Xe
2017
5 pags., 2 figs. -- Open Access funded by Creative Commons Atribution Licence 4.0. -- Presented at the XXXV Mazurian Lakes Conference on Physics, Piaski, Poland, September 3–9, 2017.
Dipole and quadrupole moments of Cu73–78 as a test of the robustness of the Z=28 shell closure near Ni78
2017
Nuclear spins and precise values of the magnetic dipole and electric quadrupole moments of the ground-states of neutron-rich $^{76-78}$Cu isotopes were measured using the Collinear Resonance Ionization Spectroscopy (CRIS) experiment at ISOLDE, CERN. The nuclear moments of the less exotic $^{73,75}$Cu isotopes were re-measured with similar precision, yielding values that are consistent with earlier measurements. The moments of the odd-odd isotopes, and $^{78}_{29}$Cu ($N=49$) in particular, are used to investigate excitations of the assumed doubly-magic $^{78}$Ni core through comparisons with large-scale shell-model calculations. Despite the narrowing of the $Z=28$ shell gap between $N\sim45…
Hyperfine structure study of Tc97,98,99 in a new laser ion source for high-resolution laser spectroscopy
2020
Using a novel concept for efficient laser spectroscopy, we investigated the hyperfine splittings of three different atomic transitions in the long-lived isotopes $^{97\ensuremath{-}99}\mathrm{Tc}$. Despite the refractory character of the element technetium, sample sizes as low as ${10}^{11}$ atoms were sufficient to achieve excellent signal-to-noise ratios at a spectroscopic linewidth of less than 100 MHz. The obtained spectra were analyzed in detail, which results in a very good consistency for the extracted hyperfine parameters from the different transitions. The presented measurements provide the first hyperfine structure data for the isotopes $^{97,98}\mathrm{Tc}$ from which, in combina…
Large shape staggering in neutron-deficient Bi isotopes
2021
The changes in the mean-square charge radius (relative to 209Bi), magnetic dipole, and electric quadrupole moments of 187,188,189,191Bi were measured using the in-source resonance-ionization spectroscopy technique at ISOLDE (CERN). A large staggering in radii was found in 187,188,189Big, manifested by a sharp radius increase for the ground state of 188Bi relative to the neighboring 187,189Big. A large isomer shift was also observed for 188Bim. Both effects happen at the same neutron number, N=105, where the shape staggering and a similar isomer shift were observed in the mercury isotopes. Experimental results are reproduced by mean-field calculations where the ground or isomeric states were…
High-resolution laser spectroscopy of Al27–32
2021
Hyperfine spectra of $^\text{27-32}$Al ($Z=13$) have been measured at the ISOLDE-CERN facility via collinear laser spectroscopy using the $3s^23p\ ^2\text{P}^\text{o} _{3/2}\rightarrow 3s^24s\ ^2\text{S}_{1/2}$ atomic transition. For the first time, mean-square charge radii of radioactive aluminum isotopes have been determined alongside the previously unknown magnetic dipole moment of $^{29}$Al and electric quadrupole moments of $^{29,30}$Al. A potentially reduced charge radius at $N=19$ may suggest an effect of the $N=20$ shell closure, which is visible in the Al chain, contrary to other isotopic chains in the $sd$ shell. The experimental results are compared to theoretical calculations in…
Nuclear Moments and Deformation Change inA184ug,mfrom Laser Spectroscopy
1997
Resonance ionization spectroscopy (RIS) was performed on desorbed Au, and the complete hyperfine spectrum of both isomeric and ground states of the short lived 184Au nucleus has been recorded from the 5d106s S1y2 ! 5d106p P3y2 optical transition. The nuclear moments of both states and the mean square charge radius changes were measured. The magnetic moments were determined to be m 184g I5 12.07s2dmN and m I2 11.44s2dmN and the spectroscopic quadrupole moments to be Q 184g s 14.65s26db and Q184m s 11.90s16d b. A difference in the mean square charge radius dkr2 c l184g,184m 20.036s3d fm2 was found. [S0031-9007(97)03992-6]
Optical Spectroscopy of Short-Lived Isotopes
1979
This chapter will concentrate on a special branch of the large field of optical spectroscopy, namely, the study of hyperfine structure (hfs) and isotope shift (IS) of short-lived isotopes. Such investigations give information on some basic properties of these nuclei: the spin ( ), the magnetic moment (μI), the spectroscopic quadrupole moment (Q s ), and the change of the mean square charge radius between different isotopes (δ〈r 2〉).