scholarly journals Lifetime measurements in 110Cd

2020 ◽  
Vol 6 ◽  
pp. 111
Author(s):  
S. Harissopulos ◽  
A. Dewald ◽  
A. Gelberg ◽  
P. Von Brentano ◽  
K. O. Zell ◽  
...  
Keyword(s):  
Decay Curve ◽  
Transition Probabilities ◽  
Yrast Band ◽  
Ground Band ◽  
Curve Method ◽  
Γ Rays ◽  
Recoil Distance ◽  
Boson Model ◽  
Shift Technique ◽  
Good Agreement

Mean lifetimes for the lowest 6 yrast band members have been measured using the Recoil Distance Doppler Shift technique (RDDS). The data have been analyzed via the Differential Decay Curve Method (DDCM). The transition probabilities deduced from the data for the ground band E2 γ-rays are in rather good agreement with the predictions of the U(5)-limit of interacting boson model-1 (IBM-1).

scholarly journals Search for E(5) Symmetry in 102Pd

2019 ◽  
Vol 18 ◽  
pp. 169
Author(s):  
S. F. Ashley ◽  
... Et al.
Keyword(s):  
Excited States ◽  
Decay Curve ◽  
Interacting Boson Model ◽  
Yrast Band ◽  
Evaporation Reaction ◽  
Curve Method ◽  
Shift Experiment ◽  
Recoil Distance ◽  
Boson Model ◽  
Fusion Evaporation Reaction

Lifetimes of the excited states in the yrast band of 102Pd have been deter- mined using the Recoil-Distance Doppler Shift experiment at INFN, Labo- ratori Nazionali di Legnaro. Excited states in 102Pd were populated by the 92Zr(13C,3n)102Pd fusion-evaporation reaction. Lifetimes were deduced using the Differential Decay Curve method and the corresponding B(E2) values were compared to the E(5) critical-point symmetry, and also the U(5) and O(6) limits of the Interacting Boson Model-1. It is evident that 102Pd agrees poorly with the predicted E(5) symmetry but has a very good (and somewhat surprising) agreement with the O(6) limit.

scholarly journals Preliminary results of lifetime measurements in neutron-rich 53Ti

2019 ◽  
Vol 223 ◽  
pp. 01022
Author(s):  
Alina Goldkuhle ◽  
Christoph Fransen ◽  
Alfred Dewald ◽  
Navin Alahari ◽  
Marcel Beckers ◽  
...  
Keyword(s):  
Transfer Reaction ◽  
Decay Curve ◽  
Yrast Band ◽  
Curve Method ◽  
Variable Mode ◽  
Multinucleon Transfer Reaction ◽  
Recoil Distance ◽  
Large Acceptance ◽  
Deep Inelastic Reactions ◽  
First Time

To study the nuclear structure of neutron-rich titanium isotopes, a lifetime measurement was performed at the Grand Accélérateur National d'Ions Lourds (GANIL) facility in Caen, France. The nucleiwere produced in a multinucleon-transfer reaction by using a 6.76 MeV/u 238U beam. The Advanced Gamma Tracking Array (AGATA) was employed for the γ-ray detection and target-like recoils were identified event-by-event by the large-acceptance variable mode spectrometer (VAMOS++). Preliminary level lifetimes of the (5/2−) to 13/2− states of the yrast band in the neutron-rich nucleus 53Ti were measured for the first time employing the recoil distance Doppler-shift (RDDS) method and the compact plunger for deep inelastic reactions. The differential decay curve method (DDCM) was used to obtain the lifetimes from the RDDS data.

Investigation of some even-even selenium isotopes within the interacting boson model-2

Open Physics ◽  
2008 ◽  
Vol 6 (3) ◽  
Author(s):  
Mahmut Böyükata ◽  
İhsan Uluer
Keyword(s):  
Transition Probabilities ◽  
Energy Levels ◽  
Mass Region ◽  
Experimental Results ◽  
Interacting Boson Model ◽  
Electromagnetic Transition ◽  
Boson Model ◽  
Selenium Isotopes ◽  
Good Agreement

AbstractThe even-even Selenium isotopes in the A∼80 mass region and the general features of its structure have been investigated within the framework of the interacting boson model-2. The neutron proton version of the model has been applied to the Se (A=74 to 80) isotopes with emphasis on the description of the 01+, 21+, 02+, 22+ and 41+ states. The energy levels, B(E2)and B(M1)electromagnetic transition probabilities were calculated. The results of these calculations were compared with previous experimental results and were shown to be in good agreement.

A theoretical study of energy spectra and transition probabilities of 200–204Hg isotopes in transitional region of IBM

2014 ◽  
Vol 23 (10) ◽  
pp. 1450056 ◽  
Author(s):  
H. Sabri
Keyword(s):  
Experimental Data ◽  
Theoretical Study ◽  
Transition Probabilities ◽  
Energy Spectra ◽  
Interacting Boson Model ◽  
Transitional Region ◽  
Transition Rates ◽  
Scale Factors ◽  
Boson Model ◽  
Good Agreement

In this paper, by using the SO(6) representation of eigenstates and transitional Interacting Boson Model (IBM) Hamiltonian, the evolution from prolate to oblate shapes along the chain of Hg isotopes is studied. Parameter-free (up to overall scale factors) predictions for spectra and B(E2) transition rates are found to be in good agreement with experimental data for 200–204 Hg isotopes which are supported to be located in this transitional region.

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.

scholarly journals Structural investigation of neutron-deficient Pt isotopes: the case of 178Pt

2019 ◽  
Vol 223 ◽  
pp. 01016
Author(s):  
Christoph Fransen ◽  
Franziska Mammes ◽  
Robert Bark ◽  
Thomas Braunroth ◽  
Zinhle Buthelezi ◽  
...  
Keyword(s):  
Ground State ◽  
Structural Investigation ◽  
Quadrupole Moments ◽  
Hartree Fock ◽  
Vibrational Ground State ◽  
Recoil Distance ◽  
Boson Model ◽  
Experimental Findings ◽  
Shift Technique ◽  
State Configuration

Lifetime measurements with the recoil distance Doppler-shift technique have been performed to determine yrast E2 transition strengths in 178Pt. The experimental data are related to those on neighboring Pt isotopes, especially recent data on 180Pt, and compared to calculations within the interacting boson model and a Hartree-Fock Bogoliubov approach. These models predict prolate deformed ground states in Pt isotopes close to neutron midshell consistent with the experimental findings. Further, evidence was found that the prolate intruder structure observed in neutron-deficient Hg isotopes that is minimum in energy in 182Hg becomes the ground state configuration in 178Pt and neighboring 180Pt with nearly identical transition quadrupole moments. The new data on 178Pt are further discussed in the context of the systematics along the Pt isotopic chain with respect to a possible sharp shape transition towards a weakly deformed or a quasi-vibrational ground state whereas the prolate structure increases in energy in 174,176Pt and becomes an intruder configuration similar to, for example, 180,182Hg.

Two-term formula for ground band energy symmetry in low-lying levels of light Mg-Zr nuclei

2015 ◽  
Vol 24 (12) ◽  
pp. 1550102
Author(s):  
Vidya Devi
Keyword(s):  
Energy Levels ◽  
Interacting Boson Model ◽  
Band Energy ◽  
Ground Band ◽  
Single Term ◽  
Energy Formula ◽  
Term Energy ◽  
Boson Model ◽  
Two Parameter ◽  
Good Agreement

In this paper, two parameter single-term energy formula [Formula: see text] is used to study the energy spin relationship within the ground bands of even–even Mg-Zr nuclei. The formula works better for the [Formula: see text]-soft nuclei as well as vibrational nuclei. We also compared it with other two-parameter formulas: Ejiri, [Formula: see text], [Formula: see text] and soft rotor formula (SRF). We also study the symmetry of the nuclei in the framework of interacting boson model (IBM-1). The IBM-1 was employed to determine the most appropriate Hamiltonian, the Hamiltonian of the IBM-1 and [Formula: see text](6) symmetry calculation, for the study of these isotopes. We have also calculated energy levels and B(E2) values for number of transitions in these [Formula: see text]Se and [Formula: see text]Kr isotopes and there is a good agreement between the presented results and the previous experimental data.

Energy Levels and Electromagnetic Transition of 90-94mo Nuclei Using Ibm-1

2020 ◽  
pp. 149-152
Keyword(s):  
Experimental Data ◽  
Transition Probability ◽  
Energy Levels ◽  
Dynamical Symmetry ◽  
Interacting Boson Model ◽  
Excitation Energies ◽  
Electromagnetic Transition ◽  
Boson Model ◽  
Energy States ◽  
Good Agreement

The energy states for the J , b , ɤ bands and electromagnetic transitions B (E2) values for even – even molybdenum 90 – 94 Mo nuclei are calculated in the present work of "the interacting boson model (IBM-1)" . The parameters of the equation of IBM-1 Hamiltonian are determined which yield the best excellent suit the experimental energy states . The positive parity of energy states are obtained by using IBS1. for program for even 90 – 94 Mo isotopes with bosons number 5 , 4 and 5 respectively. The" reduced transition probability B(E2)" of these neuclei are calculated and compared with the experimental data . The ratio of the excitation energies of the 41+ to 21+ states ( R4/2) are also calculated . The calculated and experimental (R4/2) values showed that the 90 – 94 Mo nuclei have the vibrational dynamical symmetry U(5). Good agreement was found from comparison between the calculated energy states and electric quadruple probabilities B(E2) transition of the 90–94Mo isotopes with the experimental data .

ABSOLUTE STANDARDIZATION OF RADIOACTIVE NEUTRON SOURCES: II. THE USE OF THE F19(α, n)Na22 REACTION

1959 ◽  
Vol 37 (5) ◽  
pp. 550-556 ◽  
Author(s):  
K. W. Geiger
Keyword(s):  
Nuclear Reactions ◽  
Emission Rate ◽  
Neutron Emission ◽  
National Research Council ◽  
Neutron Output ◽  
Neutron Sources ◽  
Neutron Thermalization ◽  
Γ Rays ◽  
Absolute Standardization ◽  
Good Agreement

Fluorine has only one stable isotope, F19. If neutrons are produced by the F19(α, n)Na22 reaction the neutron output can be calculated from the yield of the resulting radioactive Na22. The growth of Na22 (half-life, 2.58 years) has been measured in a neutron source consisting originally of 1.6 curies Po210 mixed with CaF2 powder. Since Na22 is a positron emitter, discrimination against γ-rays from Po210 and from nuclear reactions could be achieved by detecting the two positron annihilation quanta in coincidence. The Na22 growth has been followed over 20 months and is in agreement with the theoretical growth curve. Comparison with a calibrated Na22 source yielded a neutron emission rate of (10.70 ± 0.25) × 104 sec−1. This resulted in a neutron emission rate of (3.16 ± 0.10) × 106 sec−1 for the Ra-α-Be source of the National Research Council, in good agreement with (3.22 ± 0.05) × 106 sec−1 obtained by a neutron thermalization method.

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