Examination of phenomenological formulae in superdeformed bands of A ∼ 190,150 mass regions

2020 ◽  
Vol 29 (09) ◽  
pp. 2050081
Author(s):  
Monica Karday ◽  
Anshul Dadwal ◽  
H. M. Mittal
Keyword(s):  
Careful Analysis ◽  
Exponential Model ◽  
Mass Region ◽  
Rotational Energy ◽  
Band Head ◽  
General Nature ◽  
Model Parameters ◽  
Softness Parameter ◽  
Superdeformed Bands ◽  
Gap Parameter

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.

Level spins of superdeformed bands in A ∼ 80 mass region

2016 ◽  
Vol 25 (06) ◽  
pp. 1650038 ◽  
Author(s):  
Anshul Dadwal ◽  
H. M. Mittal ◽  
Neha Sharma
Keyword(s):  
Mass Region ◽  
Band Head ◽  
Model Parameters ◽  
Mean Square ◽  
Transition Energies ◽  
Fitting Method ◽  
Superdeformed Bands ◽  
Variable Moment ◽  
Two Parameter ◽  
Good Agreement

The models variable moment of inertia (VMI), two-parameter [Formula: see text] formula and Harris [Formula: see text] expansion have been applied to 16 rotational superdeformed bands in the [Formula: see text] mass region to obtain band head spin [Formula: see text]. The band head spins of these 16 bands in the [Formula: see text] mass region are predicted by least-squares fitting method. Intraband [Formula: see text]-rays energies are fitted in these models to extract model parameters so as to obtain a minimum root mean square (RMS) deviation between calculated and the observed transition energies. The calculated transition energies depend upon the prescribed spins. When a legitimate band head spin is assigned, the calculated transition energies are in good agreement with the observed transition energies.

Phenomenological analysis of ΔI = 4 bifurcation and identical superdeformed bands

2021 ◽  
pp. 2150012
Author(s):  
Anshul Dadwal
Keyword(s):  
Empirical Evidence ◽  
Systematic Study ◽  
Mass Region ◽  
Phenomenological Analysis ◽  
Rotational Energy ◽  
Free Parameters ◽  
Superdeformed Bands ◽  
First Time ◽  
Fluctuation Model

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.

SYSTEMATIC STUDY OF NUCLEAR SOFTNESS OF SUPERDEFORMED BANDS IN A = 190 MASS REGION

2013 ◽  
Vol 22 (08) ◽  
pp. 1350053 ◽  
Author(s):  
NEHA SHARMA ◽  
H. M. MITTAL
Keyword(s):  
Systematic Study ◽  
Gamma Ray ◽  
Neutron Number ◽  
Mass Region ◽  
Energy Ratio ◽  
Softness Parameter ◽  
Superdeformed Bands ◽  
Parameter Values ◽  
First Time ◽  
Valence Proton

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.

scholarly journals Junction Parameter Extraction for Electronic Device Characterization

2004 ◽  
Vol 27 (2) ◽  
pp. 61-67
Author(s):  
S. Dib ◽  
C. Salame ◽  
N. Toufik ◽  
A. Khoury ◽  
F. Pélanchon ◽  
...  
Keyword(s):  
Electronic Device ◽  
Control Process ◽  
Parameter Extraction ◽  
Exponential Model ◽  
Voltage Characteristic ◽  
Model Parameters ◽  
Current Voltage Characteristic ◽  
Device Characterization ◽  
Current Voltage

A new method for the extraction of junction parameters from a description of the current–voltage characteristic is developed. A simulation is performed and a high accuracy is obtained for the determination of the singleexponential model parameters. The method is easy to implement in a control process for device characterization. An application, achieved to observe the degradation of the emitter–base junction of a bipolar transistor during an aging experiment, shows that the evolutions of the single exponential model parameters versus time introduce a means for degradation quantification.

scholarly journals Dynamic Emulation of a PEM Electrolyzer by Time Constant Based Exponential Model

Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 750 ◽  
Author(s):  
Damien Guilbert ◽  
Gianpaolo Vitale
Keyword(s):  
Dynamic Behavior ◽  
Proton Exchange Membrane ◽  
Exponential Model ◽  
Proton Exchange ◽  
Operating Conditions ◽  
Experimental Investigations ◽  
Model Parameters ◽  
Dynamic Operating ◽  
Pem Electrolyzer ◽  
Current Interval

The main objective of this paper is to develop a dynamic emulator of a proton exchange membrane (PEM) electrolyzer (EL) through an equivalent electrical model. Experimental investigations have highlighted the capacitive effect of EL when subjecting to dynamic current profiles, which so far has not been reported in the literature. Thanks to a thorough experimental study, the electrical domain of a PEM EL composed of 3 cells has been modeled under dynamic operating conditions. The dynamic emulator is based on an equivalent electrical scheme that takes into consideration the dynamic behavior of the EL in cases of sudden variation in the supply current. The model parameters were identified for a suitable current interval to consider them as constant and then tested with experimental data. The obtained results through the developed dynamic emulator have demonstrated its ability to accurately replicate the dynamic behavior of a PEM EL.

scholarly journals Moments of Inertia of SDIBs in A = 190 Mass Region using VMI Model

2020 ◽  
Vol 12 (2) ◽  
pp. 209-214
Author(s):  
P. Jain ◽  
A. Goel ◽  
S. K. Mandal
Keyword(s):  
Theoretical Model ◽  
Large Range ◽  
Mass Region ◽  
Band Head ◽  
Moment Of Inertia ◽  
Moments Of Inertia ◽  
Transition Energies ◽  
Variable Moment ◽  
Dynamic Moment

A lot of identical bands are known at present in the Normal Deformed (ND) region. In our study of the occurrence and properties of identical bands in Super-Deformed (SD) nuclei we first applied the modified Variable Moment of Inertia (VMI) model to extract the band-head spin of Super-Deformed bands. The calculated transition energies, level spins and dynamic moment of inertia are systematically examined. Then, in the framework of theoretical model several identical bands are identified. The kinematic and dynamic moment of inertia have been calculated for the six pairs of Super-Deformed Identical Bands (SDIBs) which was not reported earlier in the literature. Thus, the results are significant. In all the cases J(2) is significantly higher than J(1) over a large range of frequency.

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