THEORETICAL CALCULATIONS ON α-DECAY HALF-LIVES BY THE DENSITY-DEPENDENT CLUSTER MODEL

2008 ◽  
Vol 23 (27n30) ◽  
pp. 2597-2603
Author(s):  
ZHONGZHOU REN ◽  
CHANG XU
Keyword(s):  
Cluster Model ◽  
Theoretical Calculations ◽  
Light Nuclei ◽  
Α Decay ◽  
Density Dependent ◽  
Theoretical Results ◽  
Good Agreement

The theoretical calculations of α-decay half-lives for three kinds of α-emitters (even-even, even-odd, odd-odd nuclei) are systematically reviewed within the framework of the density-dependent cluster model (DDCM). The half-lives of three typical α-emitters (8 Be , 212 Po , and 270 Ds ) are discussed in detail. The good agreement between experimental and theoretical results shows that DDCM is applicable in the whole mass table from very light nuclei to heavy and superheavy ones.

THEORETICAL STUDY ON HALF-LIVES OF EXOTIC RADIOACTIVITIES

2006 ◽  
Vol 15 (07) ◽  
pp. 1569-1575
Author(s):  
CHANG XU ◽  
ZHONGZHOU REN
Keyword(s):  
Cluster Model ◽  
Theoretical Study ◽  
Proton Emission ◽  
Decay Energy ◽  
Α Decay ◽  
Density Dependent ◽  
Quantum Tunnelling ◽  
Analytical Formulas ◽  
Unified Description ◽  
Theoretical Results

We systematically investigate the half-lives of exotic radioactivities in the framework of the density-dependent cluster model. Simple analytical formulas between lifetime and decay energy are also derived for the exotic radioactivities based on the Gamow quantum tunnelling theory. The theoretical results from the density-dependent cluster model and from the analytical formulas agree well with the experimental data. A unified description is achieved for proton emission, α-decay and cluster radioactivity by both phenomenological and microscopic methods.

DENSITY-DEPENDENT CLUSTER MODEL OF α DECAY

2005 ◽  
Vol 19 (15n17) ◽  
pp. 2365-2368 ◽  
Author(s):  
CHANG XU ◽  
ZHONGZHOU REN
Keyword(s):  
Nuclear Physics ◽  
Cluster Model ◽  
Daughter Nucleus ◽  
Nucleon Nucleon ◽  
Nucleon Interaction ◽  
Α Decay ◽  
Density Dependent ◽  
Density Distributions ◽  
Nucleon Nucleon Interaction ◽  
Double Folding

A new cluster model of α decay is proposed where the effective potential between α-cluster and daughter nucleus is obtained from the double folding integral of the renormalized M3Y nucleon-nucleon interaction and of the density distributions of α particle and daughter nucleus. Without introducing any extra adjustment on the potential, the new model (named as the density-dependent cluster model) can successfully reproduce the experimental half-lives of α decay within a factor of 3. The model also works well for new superheavy elements which are the current interests of nuclear physics and chemistry.

Absolutmessung der kontinuierlichen Strahlung des Heliums im Lichtbogen von λ = 109 bis 540 nm / Measurement of the Helium Continuum Radiation from λ = 109 to 540 nm in an Arc Plasma

1980 ◽  
Vol 35 (8) ◽  
pp. 808-819 ◽  
Author(s):  
P. Thoma
Keyword(s):  
Energy Balance ◽  
Theoretical Calculations ◽  
Continuum Emission ◽  
Kinetic Temperature ◽  
Arc Plasma ◽  
Plasma Parameters ◽  
Continuum Radiation ◽  
Theoretical Results ◽  
Helium Emission ◽  
Good Agreement

Abstract Absolute helium emission coefficients have been measured from 540 nm down to 109 nm in the near vuv. The radiation originates from the axis of a cylindrical He-arc of 2 mm ∅ at one atmosphere with electron temperatures between 25000 K and 26500 K. The electron densities range from 3.0 · 1016 cm-3 to 4.0 · 1016 cm-3 and have been determined independently from other plasma parameters by means of line shape measurements. The density of atoms and their kinetic temperature have been calculated from the energy balance of the electrons and Dalton's law. Comparison of the measured helium continuum emission coefficients with theoretical calculations in the wavelength range from 540 nm to 400 nm shows that, in this experiment, the radiation due to bremsstrahlung in the field of atoms must not be neglected. Taking into account this contribution very good agreement with theoretical calculations over the whole investigated spectral range from 540 nm down to 109 nm has been found. Thus the present experiment confirms the theoretical results for the photoionisation coefficients from the n = 2 and n = 3 levels. On the basis of these results the helium continuum radiation may be used for calibration purposes, which is of particular interest in the vuv.

SYSTEMATIC CALCULATION OF α-DECAY HALF-LIVES WITHIN GENERALIZED DENSITY-DEPENDENT CLUSTER MODEL

2010 ◽  
Vol 19 (08n09) ◽  
pp. 1592-1602 ◽  
Author(s):  
DONGDONG NI ◽  
ZHONGZHOU REN
Keyword(s):  
Wave Function ◽  
Cluster Model ◽  
Nuclear Potential ◽  
Α Decay ◽  
Density Dependent ◽  
Systematic Calculation ◽  
State Wave ◽  
Scattering State ◽  
The Difference ◽  
Double Folding

An improved version of the generalized density-dependent cluster model is presented to describe an α particle tunneling through a microscopic potential barrier. The microscopic potential is numerically constructed in the double folding model for both the Coulomb potential and the nuclear potential. The decay width is computed using the integral of the quasibound state wave function, the scattering state wave function, and the difference of potentials. We perform a systematic calculation of α-decay half-lives for even-even, odd-A, and odd-odd nuclei ranging from N = 84 to N = 126. The calculated α-decay half-lives are found to be in good agreement with the experimental values.

scholarly journals Microscopic description of α-decay as super-asymmetric fission

2021 ◽  
Vol 256 ◽  
pp. 00010
Author(s):  
Mihail Mirea
Keyword(s):  
Ground State ◽  
Parent Nucleus ◽  
Time Dependent ◽  
Coriolis Coupling ◽  
Microscopic Description ◽  
Α Decay ◽  
Least Action ◽  
Theoretical Results ◽  
Asymmetric Fission ◽  
Good Agreement

The fine structure of α-decay is treated with fission-like models. The single particle levels are calculated along a least action path connecting the ground state of the parent nucleus and the configuration of two spherical tangent nuclei. The probabilities to find different seniority-1 configurations are obtaining by solving the time-dependent pairing equations generalized by including the Landau-Zener effect and the Coriolis coupling. The theoretical results for the α-decay of 211Po and 211Bi are compared with experimental data showing a good agreement.

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