Systematic study of rotational energy formulae for superdeformed bands in La and Ce isotopes

2017 ◽  
Vol 41 (12) ◽  
pp. 124105
Author(s):  
Honey Sharma ◽  
H.M. Mittal
Author(s):  
Anshul Dadwal

For the first time, a systematic study of identical superdeformed (SD) bands in [Formula: see text] mass region is made, where [Formula: see text] bifurcation is present. Four pairs of identical SD bands viz. [Formula: see text] and [Formula: see text] of [Formula: see text] mass region and [Formula: see text] and [Formula: see text] of [Formula: see text] mass region have been systematically studied. The present systematic study provides the universal description of the identical SD bands in various mass regions. We presented the empirical evidence of a similar structure of identical SD bands in various mass regions. For this purpose, we have used various rotational energy formulae. The free parameters are extracted from four identical SD bands. The [Formula: see text] bifurcation in identical SD bands is calculated from shape fluctuation formulae. For the first time, this shape fluctuation model is employed to calculate the [Formula: see text] bifurcation, making it an alternate powerful tool to study SD bands of various mass regions.


2013 ◽  
Vol 22 (08) ◽  
pp. 1350053 ◽  
Author(s):  
NEHA SHARMA ◽  
H. M. MITTAL

A four parameter formula has been applied to obtain the nuclear softness parameter (σ) for all the superdeformed (SD) bands observed in A = 190 mass region. The nuclear softness parameter values of most of the SD bands are found to be smaller than those of the normal deformed bands, implying more rigidity. The results of this work includes the variation of nuclear softness parameter against the gamma ray energy ratio R(I) = Eγ(I→(I-2))/Eγ((I-2)→(I-4)) of SD bands in A = 190 mass region. The variation of R(I) and the nuclear softness parameter of these SD bands are studied with the product of valence proton and neutron numbers (NpNn). The systematics also includes the variation of σ with the neutron number N. It is also found that the value of softness parameter of signature partner SD bands observed in A = 190 mass region is also the same. We present for the first time the study of softness parameter of SD bands with NpNn scheme.


2020 ◽  
Vol 29 (09) ◽  
pp. 2050081
Author(s):  
Monica Karday ◽  
Anshul Dadwal ◽  
H. M. Mittal

The rotational energy formulae viz. VMI model, ab-formula, Harris [Formula: see text] expansion, Exponential model with pairing attenuation and Nuclear softness formula are employed to the superdeformed bands of [Formula: see text] and [Formula: see text] mass regions in order to test the validity of various rotational energy formulae in describing the general nature of superdeformed bands. These formulae are used to deduce the band-head spins of the nine superdeformed bands in [Formula: see text] mass region and two superdeformed bands of [Formula: see text] mass region. The band-head spins of these superdeformed bands have been established experimentally and hence they prove to be excellent candidates to examine the adequacy of rotational energy formulae in superdeformed bands. The least-squares fitting of [Formula: see text]-transition energies is performed to calculate the model parameters such as the band-head moment of inertia, the effective pairing gap parameter and the softness parameter, and a careful analysis of these parameters is made. For the first time, we have performed a systematic study of the rotational energy formulae to establish which formula gives the best estimate of spin in [Formula: see text] mass regions.


2003 ◽  
Vol 40 (3) ◽  
pp. 353-356 ◽  
Author(s):  
Zhang Da-Li ◽  
Li Jin-Bo ◽  
Ding Bin-Gang

Author(s):  
Gianluigi Botton ◽  
Gilles L'espérance

As interest for parallel EELS spectrum imaging grows in laboratories equipped with commercial spectrometers, different approaches were used in recent years by a few research groups in the development of the technique of spectrum imaging as reported in the literature. Either by controlling, with a personal computer both the microsope and the spectrometer or using more powerful workstations interfaced to conventional multichannel analysers with commercially available programs to control the microscope and the spectrometer, spectrum images can now be obtained. Work on the limits of the technique, in terms of the quantitative performance was reported, however, by the present author where a systematic study of artifacts detection limits, statistical errors as a function of desired spatial resolution and range of chemical elements to be studied in a map was carried out The aim of the present paper is to show an application of quantitative parallel EELS spectrum imaging where statistical analysis is performed at each pixel and interpretation is carried out using criteria established from the statistical analysis and variations in composition are analyzed with the help of information retreived from t/γ maps so that artifacts are avoided.


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