Search results for "nuclear structure"
showing 10 items of 401 documents
New subshell closure atN=58emerging in neutron-rich nuclei beyondNi78
2010
The structure of neutron-rich nuclei beyond $^{78}\mathrm{Ni}$ was studied using postaccelerated radioactive beams of $^{83,84,85}\mathrm{Ga}$ utilizing $\ensuremath{\beta} \ensuremath{\gamma}$ and $\ensuremath{\beta}\ensuremath{-}n \ensuremath{\gamma}$ spectroscopy. Our data, when combined with energy level systematics, suggests a possible new spherical subshell closure at $N=58$ is created by the nearly degenerated $\ensuremath{\nu}3{s}_{1/2}$ and $\ensuremath{\nu}2{d}_{5/2}$ orbitals being well separated from other orbitals above $N=50$. The near degeneracy of these states could be evidenced by isomerism in this region. The energies of the ${2}_{1}^{+}$ and proposed ${4}_{1}^{+}$ states …
Progress in Atomic Physics Experiments on Nuclear Properties
1992
The measurement of nuclear properties by atomic physics methods has influenced a great deal of our present understanding of the nuclear structure. This started from the discovery of the nuclear spin and magnetic moment, the observation of isotope shifts related to nuclear radii, and the resolution of quadrupole interaction effects in the hyperfine structures. The invention and improvement of many spectroscopic techniques has led to a comprehensive knowledge of the electromagnetic ground-state properties of all stable and many radioactive nuclides. On the other hand, the atomic and thus the nuclear masses of stable isotopes were determined very precisely by electromagnetic mass spectrometry.…
Nuclear structure with radioactive muonic atoms
2018
Muonic atoms have been used to extract the most accurate nuclear charge radii based on the detection of X-rays from the muonic cascades. Most stable and a few unstable isotopes have been investigated with muonic atom spectroscopy techniques. A new research project recently started at the Paul Scherrer Institut aims to extend the highresolution muonic atom spectroscopy for the precise determination of nuclear charge radii and other nuclear structure properties of radioactive isotopes. The challenge to combine the high-energy muon beam with small quantity of stopping mass is being addressed by developing the concept of stopping the muon in a high-density, a high-pressure hydrogen cell and sub…
Precision measurement of structure function ratios for $^{6}$Li, $^{12}$C and $^{40}$Ca
1992
The structure function ratiosF2C/F2Li,F2Ca/F2Li andF2Ca/F2C were measured in deep inelastic muonnucleus scattering at an incident muon energy of 90 GeV, covering the kinematic range 0.0085<x<0.6 and 0.8<Q2<17GeV2. The sensitivity of the nuclear structure functions to the size and mean density of the target nucleus is discussed.
FINITE-RANGE SEPARABLE PAIRING INTERACTION WITHIN NEW N[sup 3]LO DFT APPROACH
2011
For over four decades, the Skyrme functional within various parametrizations has been used to calculate nuclear properties. In the last few years there was a number of attempts to improve its performance and introduce generalized forms. In particular, the most general phenomenologi‐cal quasi‐local energy density functional, which contains all combinations of density, spin‐density, and their derivatives up to the sixth order (N3LO), was proposed in reference [1]. Since in the phe‐nomenological functional approaches the particle‐particle (pp) interaction channel is treated independently from the particle‐hole (ph) channel, there remains a question of what pairing interaction is suitable to us…
Pion Scattering and Pion Photoproduction on 3He
1992
Using realistic 3-body Faddeev wave functions π± scattering and π+ photoproduction on 3He have been calculated in a consistent model. We demonstrate that at T π ≤ 180MeV polarization observables in pion scattering contain very little information about nuclear structure and can be understood in terms of free πN amplitudes. At higher energies the sign-flip of the asymmetry A y offers a new possibility to study higher-order effects of pion nuclear interaction. In pion photoproduction we find that two-step processes such as 3 He(γ, π°)3 He(π°, π+)3 H give rise to unexpected large contributions to the differential crosssection as well as to γ-asymmetry and with this improved a long time discrepa…
The features of electronics structure of the multichannel scintillation module for the EMMA experiment
2011
A brief description of the developed structural electric diagrams of 16-channel scintillation module for the underground EMMA experiment, the basic characteristics and parameters of the electrical diagrams of this module are presented. Multi-pixel photodiodes operating in a limited Geiger mode are used for photoreadout of the scintillator detectors in 16-channel scintillation module. The method of the automatic tuning of the photosensors gain based on the stabilization of an average counting rate of the scintillation detectors from gamma rays of a natural radioactive background is described. peerReviewed
New Information on Nuclear Structure in the Cd-In-Sn Region from Laser Spectroscopy and the Question of Core Polarization Contribution to Nuclear Rad…
1986
Nuclear spin, moments and isotope shifts of charge radii have been measured by laser spectroscopy for about 70 nuclear states in the range 48 ≦ Z ≦ 50, 54 ≦ N ≦ 78. 1/2--states in heavy In-isotopes cross the Schmidt line, indicating complex nuclear structure. Magnetic as well as spectroscopic quadrupole moments of most of the odd odd In-isotopes can be reproduced satisfactorily by coupling the respective experimental moments of odd even and even odd neighbouring nuclei. The isotope shift of all three elements exhibits a parabolic shape, which is superimposed to the almost linear droplet model expectation. The shape can be fitted quantitatively to Talmis core polarization model. The curvatur…
Lifetime measurements of excited states in neutron-rich Ti53 : Benchmarking effective shell-model interactions
2020
Level lifetimes of the yrast (5/2(-)) to 13/2(-) states in the neutron-rich nucleus Ti-53, produced in a multinucleon-transfer reaction, have been measured for the first time. The recoil distance Doppler-shift method was employed and lifetimes of the excited states were extracted by a lineshape analysis aided by GEANT4-based Monte-Carlo simulations. The experiment was performed at the Grand Accelerateur National d'Ions Lourds facility in Caen, France, by using the Advanced Gamma Tracking Array for the gamma-ray detection coupled to the large-acceptance variable mode spectrometer for an event-by-event particle identification and the Cologne plunger for deep-inelastic reactions. Reduced trans…
Shape coexistence in neutron-deficient Hg188 investigated via lifetime measurements
2020
Background: Shape coexistence in the Z≈82 region has been established in mercury, lead, and polonium isotopes. For even-even mercury isotopes with 100≤N≤106 multiple fingerprints of this phenomenon are observed, which seems to be no longer present for N≥110. According to a number of theoretical calculations, shape coexistence is predicted in the Hg188 isotope. Purpose: The aim of this work was to measure lifetimes of excited states in Hg188 to infer their collective properties, such as the deformation. Extending the investigation to higher-spin states, which are expected to be less affected by band-mixing effects, can provide additional information on the coexisting structures. Methods: The…