scholarly journals Lifetime measurements in 105Sn: the puzzle of B(E2) strengths in Sn isotopes

2019 ◽  
Vol 223 ◽  
pp. 01048
Author(s):  
Giorgia Pasqualato ◽  
Andrea Gottardo ◽  
Alain Goasduff ◽  
Josè Javier Valiente Dobón ◽  
Daniele Mengoni
Keyword(s):  
Excited States ◽  
Experimental Technique ◽  
Systematic Study ◽  
Doppler Shift ◽  
Isotopic Chain ◽  
Lifetime Measurements ◽  
Preliminary Results ◽  
Shell Closures ◽  
Recoil Distance ◽  
Good Agreement

One of the most studied case to explore the evolution of shell closures far from stability is the doubly-magic and self-conjugated 100Sn nucleus. Information on its doubly-magic nature can be extracted fromthe systematic study of the tin isotopic chain. In this context, the lifetimes of the neutron deficient 105Sn have been investigated with the coincidence Recoil Distance Doppler Shift (RDDS) technique throughthe reaction 50Cr(58Ni,2pn)105Sn. Preliminary results concerning the lifetimesof 105In excited states are in good agreement with the adopted lifetimes, demonstrating the feasibility to extract lifetimes with this experimental technique.

scholarly journals Nuclear structure in the neutron-deficient Sn nuclei TKEL effects on lifetime measurements

2019 ◽  
Vol 223 ◽  
pp. 01060 ◽  
Author(s):  
Marco Siciliano ◽  
José-Javier Valiente-Dobón ◽  
Alain Goasduff
Keyword(s):  
Excited States ◽  
Transfer Reaction ◽  
Electromagnetic Properties ◽  
Isotopic Chain ◽  
Lifetime Measurements ◽  
Experimental Limitation ◽  
Recoil Distance ◽  
First Time ◽  
Shift Technique ◽  
Kinetic Energy Loss

The presence of seniority-like isomers along the Z = 50 isotopic chain have been an experimental limitation to the investigation of the electromagnetic properties of the low-lying states in the light Sn nuclei. Combining a multi-nucleon transfer reaction with the Recoil-Distance Doppler-Shift technique, the lifetimes of the 21+ and 41+ excited states have been directly measured in the neutron-deficient 106, 108Sn isotopes for the very first time. The emitted γ rays were detected by the AGATA array, while the reactionproducts were uniquely identified by the VAMOS++ magnetic spectrometer. The control of the direct feeding of the statesby gating on the Total Kinetic Energy Loss, together with the unique capabilities of the two spectrometers, was crucial for the measurementin 108Sn.

EVIDENCE FOR X(5) CRITICAL POINT SYMMETRY IN 128Ce

2006 ◽  
Vol 15 (08) ◽  
pp. 1735-1740 ◽  
Author(s):  
D. L. BALABANSKI ◽  
K. A. GLADNISHKI ◽  
G. LO BIANCO ◽  
A. SALTARELLI ◽  
N. V. ZAMFIR ◽  
...  
Keyword(s):  
Critical Point ◽  
Nuclear Structure ◽  
Excited States ◽  
Ground State ◽  
Doppler Shift ◽  
Point Symmetry ◽  
Yale University ◽  
Doppler Shift Attenuation ◽  
Recoil Distance ◽  
Predicted Values

Lifetimes of excited states in 128 Ce were measured using the recoil distance Doppler-shift (RDDS) and the Doppler-shift attenuation (DSAM) methods. The experiments were performed at the Wright Nuclear Structure Laboratory of Yale University. Excited states of 128 Ce were populated in the 100 Mo (32 Si ,4 n ) reaction at 120 MeV and the nuclear γ decay was measured with an array of eight Clover detectors positioned at forward and backward angles. The deduced yrast transition strengths together with the energies of the levels within the ground-state (gs) band of 128 Ce are in agreement with the predicted values for the X (5) critical point symmetry. Thus, we suggest 128 Ce as a benchmark X (5) nucleus in the mass A ≈ 130 region.

LIFETIME MEASUREMENTS IN 134Pr AND CHIRALITY IN NUCLEI

2006 ◽  
Vol 15 (07) ◽  
pp. 1531-1540 ◽  
Author(s):  
D. TONEV ◽  
P. PETKOV ◽  
D. L. BALABANSKI ◽  
G. DE ANGELIS ◽  
A. GADEA ◽  
...  
Keyword(s):  
Doppler Shift ◽  
Transition Probabilities ◽  
Experimental Results ◽  
Lifetime Measurements ◽  
Evaporation Reaction ◽  
Doppler Shift Attenuation ◽  
Recoil Distance ◽  
Reduced Transition Probabilities ◽  
Fusion Evaporation Reaction

Lifetimes of exited states in 134 Pr were measured be means of the recoil distance Doppler-shift and Doppler-shift attenuation techniques. The experiments were performed at IReS, Strasbourg using the EUROBALL IV spectrometer, in conjunction with the inner BGO ball and the Cologne coincidence plunger apparatus. Exited states in 134 Pr were populated in the fusion-evaporation reaction 119 Sn (19 F , 4 n )134 Pr . Reduced transition probabilities in 134 Pr are compared to the predictions of the two quasiparticle+triaxial rotor and interacting boson fermion-fermion models. The experimental results do not support the presence of static chirality in 134 Pr underlying the importance of shape fluctuations. Only within a dynamical context the presence of intrinsic chirality in 134 Pr can be supported.

scholarly journals Symmetries in mirror nuclei 31S and 31P

2018 ◽  
Vol 194 ◽  
pp. 03001
Author(s):  
D. Tonev ◽  
G. de Angelis ◽  
N. Goutev ◽  
S. Iliev ◽  
R. Orlandi ◽  
...  
Keyword(s):  
Charged Particle ◽  
Excited States ◽  
Doppler Shift ◽  
Isospin Symmetry ◽  
Particle Detector ◽  
Lifetime Measurements ◽  
Angular Correlations ◽  
Doppler Shift Attenuation ◽  
First Time

Excited states in mirror nuclei 31S and 31P were populated in the 1n and 1p exit channels, respectively, of the reaction 20Ne + 12C. The beam of 20Ne, with an energy of 33 MeV, was delivered for the first time by the Piave-Alpi accelerator of the Laboratori Nazionali di Legnaro. Angular correlations of coincident pairs and Doppler-shift attenuation lifetime measurements in 31S and 31P were performed using the multidetector array GASP in conjunction with the EUCLIDES charged particle detector. A comparison of the determined B(E1) strengths of the analog mirror 7/2- → 5/2+ transitions indicates the presence of a violation of isospin symmetry.

Coincidence recoil-distance Doppler-shift lifetime measurements in128Ba

2000 ◽  
Vol 62 (1) ◽  
Author(s):  
P. Petkov ◽  
A. Dewald ◽  
R. Kühn ◽  
R. Peusquens ◽  
D. Tonev ◽  
...  
Keyword(s):  
Doppler Shift ◽  
Lifetime Measurements ◽  
Recoil Distance

scholarly journals Lifetimes and electromagnetic transition strength in 124Ba

2018 ◽  
Vol 194 ◽  
pp. 03004
Author(s):  
Mariya Trichkova ◽  
Marcel Beckers ◽  
Kalin Gladnishki ◽  
Alfred Dewald ◽  
Andrey Blazhev ◽  
...  
Keyword(s):  
Excited States ◽  
Doppler Shift ◽  
Structural Changes ◽  
Decay Curve ◽  
Transition Strength ◽  
Electromagnetic Transition ◽  
Coincidence Data ◽  
Curve Method ◽  
Recoil Distance ◽  
Γ Ray

Lifetimes of excited states of 124Ba were measured by the Recoil Distance Doppler Shift (RDDS) technique. The γ-ray coincidence data were analysed by the Differential Decay Curve method (DDCM). The trend of the experimentally deduced normalized B(E2) values reveals a drop at the 8+1 state, which may be caused by structural changes in the backbending region.

LIFETIME MEASUREMENTS OF EXCITED STATES IN 73As

2004 ◽  
Vol 13 (05) ◽  
pp. 1019-1034 ◽  
Author(s):  
K. P. SINGH ◽  
T. KAKAVAND ◽  
M. HAJIVALIEI
Keyword(s):  
Statistical Theory ◽  
Excited States ◽  
Doppler Shift ◽  
Nuclear Reactions ◽  
Angular Distributions ◽  
Excitation Energies ◽  
Lifetime Measurements ◽  
Mixing Ratios ◽  
Doppler Shift Attenuation ◽  
First Time

The excited states of 73 As have been investigated via the 73 Ge ( p , n γ)73 As reaction with proton beam energies from 2.5–4.3 MeV. The lifetimes of the levels at 769.6, 860.5, 1177.8, 1188.7, 1274.9, 1344.1, 1557.1 and 1975.2 keV excitation energies have been measured for the first time using the Doppler shift attenuation method. The angular distributions have been used to assign the spins and the multipole mixing ratios using statistical theory for compound nuclear reactions. The ambiguity in the spin values for the various levels has been removed. The multipole mixing ratios for eight γ-transitions have been newly measured.

scholarly journals Lifetime Measurements at NCSR “Demokritos”

2020 ◽  
Vol 19 ◽  
pp. 41
Author(s):  
S. F. Ashley ◽  
M. Axiotis ◽  
V. Foteinou ◽  
S. Harrisopulos ◽  
T. Konstantinopoulos ◽  
...  
Keyword(s):  
Excited States ◽  
Proton Scattering ◽  
Lifetime Measurements ◽  
Values Development ◽  
Hpge Detectors ◽  
Doppler Shift Attenuation ◽  
Inelastic Proton Scattering ◽  
Γ Rays ◽  
Set Up ◽  
Good Agreement

Proof-of-principle inelastic proton scattering measurements have been performed at NCSR “Demokritos”. Excited states in 64Zn and 92Mo were populated using the (p,p'γ) reaction with E(p) = 7 MeV. The reaction γ rays were detected using four HPGe detectors at eight separate angles, with respect to the beam-axis. From Doppler-shift attenuation of the ∞ rays, lifetimes for eight excited states in 64Zn and for the Iπ = 2^+_2 and 2^+_3 states in 92Mo were deduced. The lifetimes measured in 92Mo are in good agreement with adopted values whereas the lifetimes measured in 64Zn are typically longer than the literature values. Development of the experimental set-up and potential novel physics cases where this reaction could be used are briefly discussed.

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