Conversion-electron and gamma–gamma directional correlation measurements in 134Ba

1990 ◽  
Vol 68 (12) ◽  
pp. 1479-1485 ◽  
Author(s):  
Bakhshish Chand ◽  
Jatinder Goswamy ◽  
Devinder Mehta ◽  
Nirmal Singh ◽  
P. N. Trehan

Conversion electrons from the decay of 134Cs have been investigated using a mini-orange electron spectrometer. The electron intensities for the K-conversion of 242.7 keV and L, (M + N … ) conversion of 563.2, 795.9, 801.9, 1038.6, 1167.9, and 1365.2 keV transitions in 134Ba are being reported for the first time. The conversion-electron data have been further used to determine the conversion coefficients for various transitions in, 34Ba. Also, the gamma–gamma directional correlation measurements for seven cascades in 134Ba have been carried out using a HPGe–HPGe detector coincidence setup. The multipole admixtures for the 475.3, 563.2, 569.3, 795.9, 801.9, 1038.6, and 1365.2 keV transitions have been deduced from these measurements. A multipole admixture of M1 + 37% E2 has been obtained for the 1038.6 keV transition in 134Ba. The reduced transition probability ratios for the transitions de-exciting second 2+ and 3+ energy levels in 134Ba have been calculated and compared with the values predicted by the triaxial rotor model for γ = 28.5°. This indicates the softness of the, 134Ba nucleus toward γ deformation.

2020 ◽  
Vol 35 (10) ◽  
pp. 2050062
Author(s):  
Abdullah Engin Çalık ◽  
Kaan Manisa ◽  
Ahmet Biçer ◽  
Mehmet Erdoğan ◽  
Mürsel Şen ◽  
...  

Photonuclear reactions have great importance in understanding the structure of the nuclei. These reactions, performed using the gamma rays obtained by way of bremsstrahlung, are a standard nuclear physics experiment. In this study, a non-enriched barium sample was activated for the first time by using a clinical linear accelerator (cLINACs). The spectrum of barium radioisotopes was obtained by using a gamma spectrometry with a high purity germanium (HPGe) detector. The obtained spectroscopic data were analyzed and energy levels and half-life values together with their uncertainties were obtained. Some energy levels and half-lives of [Formula: see text]Ba were determined with more precision than those of literature values.


1971 ◽  
Vol 26 (3) ◽  
pp. 405-418
Author(s):  
W. Mampe ◽  
T. von Egidy ◽  
W. Kaiser ◽  
K. Schreckenbach

Abstract Approximately 165 conversion electron lines from slow neutron capture in 199Hg have been measured with the beta spectrometer at the reactor FRM between 900 keV and 8 MeV. The high energy K-conversion coefficients of El and Ml transitions are separated distinctly and agree very well with theoretical calculations, which have been performed by several groups recently. High energy L-conversion electron coefficients have been measured for the first time with such a degree of accuracy that different multipole orders are separated and a comparison with theoretical values is possible. 6 known levels above 2 MeV have been assigned 1+ and 14 new levels have been established. 145 lines have been placed into the level scheme and new level energies have been calculated. A new 0+ level has been found at 1856.97 ± 0.1 keV.


2016 ◽  
Vol 94 (1) ◽  
pp. 23-25 ◽  
Author(s):  
G. Çelik ◽  
Ş. Ateş ◽  
G. Tekeli

The electric dipole transition probabilities, oscillator strengths, and lifetimes for Co16+ have been calculated within the weakest bound electron potential model (WBEPM) theory using experimental energy levels and theoretical expectation values of orbital radii corresponding to those energy levels under the assumption of the LS coupling scheme. In the calculations both multiplet and fine structure transitions are studied. The present results are consistent with earlier results given in the literature. Moreover, some transition probability and oscillator strength values not existing in the literature are reported for the first time.


1974 ◽  
Vol 52 (6) ◽  
pp. 488-498 ◽  
Author(s):  
J. L. Campbell ◽  
L. A. McNelles ◽  
J. S. Geiger ◽  
R. L. Graham ◽  
J. S. Merritt

The L2 and L3 subshell fluorescence yields, ω2 and ω3, and the Coster–Kronig transition probability f23 in 88Ra and 94Pu have been deduced from conversion electron L X-ray coincidence measurements. The Chalk River [Formula: see text]-spectrometer was used to select the conversion electrons. X rays were detected in a Si(Li) counter which was calibrated for absolute X-ray detection efficiency. The results are as follows: [Formula: see text]


1991 ◽  
Vol 69 (2) ◽  
pp. 90-101 ◽  
Author(s):  
Bakhshish Chand ◽  
Jatinder Goswamy ◽  
Devinder Mehta ◽  
Nirmal Singh ◽  
P. N. Trehan

The intensities of X rays and γ rays from the decays of 140Ba and 140La were measured precisely using Si(Li) and HPGe detectors. The L X-ray intensities in 140Ba decay are reported for the first time. The conversion electrons from these decays are investigated using a mini-orange electron spectrometer. The electron intensities for the (M + N.) conversion of 329, 487, 1596, and 1903 keV transitions in 140Ce were measured for the first time. From the present conversion-electron and γ-ray intensities, the conversion coefficients for various transitions in 140La and 140Ce were determined. Also, the γ–γ directional correlations for 15 cascades in,140Ce were studied using a HPGe–HPGe detector coincidence setup (time resolution = 7 ns). The 109–(329)– 487, 131–242, and 131–266 keV cascades in 140Ce were studied for the first time. The multipole mixing ratios for the 109, 131, 242, 266, 329, 432, 487, 751, 816, 868, 919, 925, and 951 keV transitions in 140Ce are deduced from the present directional correlation and conversion-coefficient measurements.


2020 ◽  
pp. 149-152

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 .


Atoms ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 48
Author(s):  
M. Raineri ◽  
M. Gallardo ◽  
J. Reyna Almandos ◽  
A. G. Trigueiros ◽  
C. J. B. Pagan

A capillary pulsed-discharge and a theta-pinch were used to record Kr spectra in the region of 330–4800 Å. A set of 168 transitions of these spectra were classified for the first time. We extended the analysis to twenty-five new energy levels belonging to 3s23p24d, 3s23p25d even configurations. We calculated weighted transition probabilities (gA) for all of the experimentally observed lines and lifetimes for new energy levels using a relativistic Hartree–Fock method, including core-polarization effects.


2017 ◽  
Vol 95 (9) ◽  
pp. 805-810 ◽  
Author(s):  
M. Raineri ◽  
M. Gallardo ◽  
J. Reyna Almandos ◽  
C.J.B. Pagan ◽  
R. Sarmiento

A pulsed discharge light source to study the six and seven times ionized xenon spectra in the 419–4642 Å region was used. A set of 40 transitions of Xe VII and 25 transitions of Xe VIII were classified for the first time. We revised the values for the previously known energy levels and extended the analysis for Xe VII to 10 new energy levels belonging to 5s6d, 5s7s and 5s7p, 4d95s25p even and odd configurations, respectively. Seven new energy levels of the core excited configuration 4d95s5d of Xe VIII are presented. For the prediction of the atomic parameters, energy levels, and transition, relativistic Hartree–Fock calculations were used.


2021 ◽  
Vol 66 (4) ◽  
pp. 293
Author(s):  
A.A. Al-Sammarraie ◽  
F.A. Ahmed ◽  
A.A. Okhunov

The negative-parity states of 24Mg nucleus are investigated within the shell model. We are based on the calculations of energy levels, total squared form factors, and transition probability using the p-sd-pf (PSDPF) Hamiltonian in a large model space (0 + 1) hW. The comparison between the experimental and theoretical states showed a good agreement within a truncated model space. The PSDPF-based calculations successfully reproduced the data on the total squared form factors and transition probabilities of the negative-parity states in 24Mg nucleus. These quantities depend on the one-body density matrix elements that are obtained from the PSDPF Hamiltonian. The wave functions of radial one-particle matrix elements calculated with the harmonic-oscillator potential are suitable to predict experimental data by changing the center-of-mass corrections.


2021 ◽  
Author(s):  
Nicolaj Kofod ◽  
Lea Gundorff Nielsen ◽  
Thomas Just Sørensen

The trivalent lanthanide ions show optical transitions between energy levels within the 4f shell. All these transitions are formally forbidden according to the quantum mechanical selection rules used in molecular photophysics. Nevertheless, highly luminescent complexes can be achieved, and terbium(iii) and europium(iii) ions are particularly efficient emitters. This report started when an apparent lack of data in the literature led us to revisit the fundamental photophysics of europium(iii). The photophysical properties of two complexes – [Eu.DOTA(MeOH-d4)]- and [Eu(MeOH-d4)9]3+ – were investigated in deuterated methanol at five different temperatures. Absorption spectra showed decreased absorption cross sections as the temperature was increased. Luminescence spectra and time-resolved emission decay profiles showed a decrease in intensity and lifetime as a temperature was increased. Having corrected the emission spectra for the actual number of absorbed photons and differences in non-radiative pathways, the relative emission probability was revealed. These were found to increase with increasing temperature. The transition probability for luminescence was shown to increase with temperature, while the transition probability for light absorption decreased. The changes in transition probabilities were correlated to a change in the symmetry of the absorber or emitter, with an average increase in symmetry lowering absorption cross section and access to more asymmetric structures increasing the emission rate constant. Determining luminescence quantum yields and the Einstein coefficient for spontaneous emission allowed us to conclude that lowering symmetry increases both. Further, it was found that collisional self-quenching is an issue for lanthanide luminescence, when high concentrations are used. Finally, detailed analysis revealed results that show the so-called ‘Werts’ method’ for calculating radiative lifetimes and intrinsic quantum yields are based on assumption that does not hold for the two systems investigated here. We conclude that we are lacking a good theoretical description of the intraconfigurational f-f transition, and that there are still aspects of fundamental lanthanide photophysics to be explored.<br>


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