Search results for "Coulomb [interaction]"

Interweaving of elementary modes of excitation in superfluid nuclei through particle-vibration coupling: Quantitative account of the variety of nucle…

2015

A complete characterization of the structure of nuclei can be obtained by combining information arising from inelastic scattering, Coulomb excitation, and $\ensuremath{\gamma}$-decay, together with one- and two-particle transfer reactions. In this way it is possible to probe both the single-particle and collective components of the nuclear many-body wave function resulting from the coupling of these modes and, as a result, diagonalizing the low-energy Hamiltonian. We address the question of how accurately such a description can account for experimental observations in the case of superfluid nuclei. Our treatment goes beyond the traditional approach, in which these properties are calculated …

Proton-Deuteron Break Up Including Coulomb Effects

1994

The first results of the calculation of proton-deuteron break-up cross sections are presented and compared with experimental data.

Shapes and Collectivity in Neutron Deficient Even-Mass 188–198Pb Isotopes

2015

Thermonuclear reactionS30(p,γ)Cl31studied via Coulomb breakup ofCl31

2014

Coulomb breakup at high energy in inverse kinematics of proton-rich Cl-31 was used to constrain the thermonuclear S-30(p,gamma)Cl-31 capture reaction rate under typical Type I x-ray burst conditions. This reaction is a bottleneck during rapid proton-capture nucleosynthesis (rp process), where its rate depends predominantly on the nuclear structure of Cl-31. Two low-lying states just above the proton-separation threshold of S-p = 296( 50) keV in Cl-31 have been identified experimentally using the (RB)-B-3-LAND setup at the GSI Helmholtzzentrum fur Schwerionenforschung GmbH. Both states are considered to play a key role in the thermonuclear S-30( p,gamma)Cl-31 capture reaction. Excitation ene…

Collective 2$^{+1}$ excitations in$^{206}$Po and$^{208,210}$Rn

2016

In the present study, $B(E2; 2^{+}_{1}\rightarrow 0^{+}_{1})$ values have been measured in the 208,210Rn and 206Po nuclei through Coulomb excitation of re-accelerated radioactive beams in inverse kinematics at CERN-ISOLDE. These nuclei have been proposed to lie in, or at the boundary of the region where the seniority scheme should persist. However, contributions from collective excitations are likely to be present when moving away from the N=126 closed shell. Such an effect is confirmed by the observed increased collectivity of the $2^{+}_{1}\rightarrow 0^{+}_{1}$ transitions. Experimental results have been interpreted with the aid of theoretical studies carried out within the BCS-based QRP…

A new recoil distance technique using low energy coulomb excitation in inverse kinematics

2011

Abstract We report on the first experiment combining the Recoil Distance Doppler Shift technique and multistep Coulomb excitation in inverse kinematics at beam energies of 3–10 A MeV. The setup involves a standard plunger device equipped with a degrader foil instead of the normally used stopper foil. An array of particle detectors is positioned at forward angles to detect target-like recoil nuclei which are used as a trigger to discriminate against excitations in the degrader foil. The method has been successfully applied to measure lifetimes in 128Xe and is suited to be a useful tool for experiments with radioactive ion beams.

Coulomb Excitation ofCu68,70: First Use of Postaccelerated Isomeric Beams

2007

We report on the first low-energy Coulomb excitation measurements with radioactive Ipi=6- beams of odd-odd nuclei 68,70Cu. The beams were produced at ISOLDE, CERN and were post-accelerated by REX-ISOLDE to 2.83 MeV/nucleon. gamma rays were detected with the MINIBALL spectrometer. The 6- beam was used to study the multiplet of states (3-, 4-, 5-, 6-) arising from the pi2p3/2nu1g9/2 configuration. The 4- state of the multiplet was populated via Coulomb excitation and the B(E2;6--->4-) value was determined in both nuclei. The results obtained illustrate the fragile stability of the Z=28 shell and N=40 subshell closures. A comparison with large-scale shell-model calculations using the 56Ni core…

Study of M1 and E1 excitations by high-resolution proton inelastic scattering measurement at forward angles

2007

Experimental technique for measuring proton inelastic scattering with high‐resolution at 295 MeV and at forward angles including zero degrees is described. The method is useful for extracting spin part of the M1 strength via nuclear excitation as well as E1 strength via Coulomb excitation. An excitation energy resolution of 20 keV, good scattering angle resolution, and low background condition have been achieved. The experimental technique was applied for several sd and pf shell nuclei.

Spectral distribution and Coulomb correction for nuclear bremsstrahlung induced by heavy targets

2021

Abstract Bremsstrahlung spectra below 250 MeV have been measured colliding 500 MeV–electrons with Cu, Ag, and Au targets. The experimental intensity ratios relative to Cu are well described by an accurate analytical high-energy theory, which accounts both for Coulomb distortion and screening. This represents the first experimental verification of the discovery by Bethe-Maximon that leading-order quantum mechanical calculations, equivalent to quasiclassical approximations, become exact at high energies and small angles. It also shows that radiative QED effects play a minor role in the covered part of the spectral distribution within the accuracy (1.6%) of the present measurements.

Shape ofAr44: Onset of deformation in neutron-rich nuclei nearCa48

2009

The development of deformation and shape coexistence in the vicinity of doubly magic $^{48}\mathrm{Ca}$, related to the weakening of the $N=28$ shell closure, was addressed in a low-energy Coulomb excitation experiment using a radioactive $^{44}\mathrm{Ar}$ beam from the SPIRAL facility at GANIL. The ${2}_{1}^{+}$ and ${2}_{2}^{+}$ states in $^{44}\mathrm{Ar}$ were excited on $^{208}\mathrm{Pb}$ and $^{109}\mathrm{Ag}$ targets at two different beam energies. $B(E2)$ values between all observed states and the spectroscopic quadrupole moment of the ${2}_{1}^{+}$ state were extracted from the differential Coulomb excitation cross sections, indicating a prolate shape of the $^{44}\mathrm{Ar}$ n…