Formation and decay of the compound nucleus Th*220 within the dynamical cluster-decay model

2017 ◽  
Vol 95 (1) ◽  
Author(s):  
Hemdeep ◽  
Sahila Chopra ◽  
Arshdeep Kaur ◽  
Raj K. Gupta
Keyword(s):  
Compound Nucleus ◽  
Cluster Decay ◽  
Decay Model

Systematic decay analysis of 202Po∗ compound nucleus using Dynamical Cluster-decay Model

2019 ◽  
Vol 28 (12) ◽  
pp. 1950105 ◽  
Author(s):  
Pooja Kaushal ◽  
Manoj K. Sharma
Keyword(s):  
Cross Section ◽  
Compound Nucleus ◽  
Cross Sections ◽  
Degrees Of Freedom ◽  
Cluster Decay ◽  
Channel Cross Section ◽  
Decay Model ◽  
Cross Section Formula ◽  
Collective Clusterization ◽  
Mechanical Fragmentation

The decay analysis of [Formula: see text]Po[Formula: see text] compound nucleus (CN), formed via [Formula: see text]Ca+[Formula: see text]Gd reaction, with inclusion of additional degrees-of-freedom, i.e., the higher multipole deformations, the octupole ([Formula: see text]) and hexadecupole ([Formula: see text]), the corresponding “compact” orientations ([Formula: see text]), and noncoplanarity degree-of-freedom ([Formula: see text]0), is investigated within the collective clusterization approach. The Quantum Mechanical Fragmentation Theory (QMFT)-based Dynamical Cluster-decay Model (DCM), wherein the point of penetration [Formula: see text], fixed via the in-built neck-length parameter [Formula: see text] in [Formula: see text] (equivalently, the “barrier lowering” [Formula: see text]), is used to best fit the channel cross-section ([Formula: see text]) and predict the quasi-fission (qf)-like nCN cross-section [Formula: see text], if any, and the fusion–fission ([Formula: see text]) cross-sections. We also look for other target-projectile (t-p) combinations for the synthesis of CN [Formula: see text]Po[Formula: see text].

DECAY OF 202Pb* FORMED IN 48Ca+154Sm REACTION USING THE DYNAMICAL CLUSTER-DECAY MODEL

2009 ◽  
Vol 18 (07) ◽  
pp. 1453-1467 ◽  
Author(s):  
SHEFALI KANWAR ◽  
MANOJ K. SHARMA ◽  
BIRBIKRAM SINGH ◽  
RAJ K. GUPTA ◽  
WALTER GREINER
Keyword(s):  
Cross Section ◽  
Compound Nucleus ◽  
Fission Cross Section ◽  
Evaporation Residue ◽  
Entrance Channel ◽  
Cluster Decay ◽  
Excitation Energies ◽  
Shell Effects ◽  
Decay Model ◽  
Symmetric Fission

The decay of compound nucleus 202 Pb *, formed in entrance channel reaction 48 Ca +154 Sm at different incident energies, is studied by using the dynamical cluster-decay model (DCM) where all decay products are calculated as emissions of preformed clusters through the interaction barriers. The calculated results show an excellent agreement with experimental data for the fusion-evaporation residue cross-section σ ER together with the fusion-fission cross-section σ FF (taken as a sum of the energetically favored symmetric [Formula: see text] and near symmetric A=65–75 plus complementary fragments), and the competing, non-compound-nucleus quasi-fission cross-section σ QF where the entrance channel is considered not to loose its identity (and hence with preformation factor P0=1). The interesting feature of this study is that the three decay processes (ER, FF and QF) are quite comparable at low energies, ER being the most dominant, whereas at higher energies FF becomes most probable followed by ER and QF. The prediction of two fission windows, the symmetric fission (SF) and the near symmetric fission (nSF) whose contribution is more at lower incident energies, suggests the presence of a fine structure effect in the fusion-fission of 202 Pb *. This result is attributed to the shell effects (magic shells) playing effective role in the fragment preformation yields for 48 Ca +154 Sm reaction at lower excitation energies, giving rise to "shoulders", to an otherwise Gaussian FF mass distribution, responsible for the QF process. As a further verification of this result, absence of "shoulders" (hence, the QF component) in the decay of 192 Pb * due to 48 Ca +144 Sm reaction is also shown to be given by the calculations, in agreement with experiments. The only parameter of the model is the neck-length ΔR which shows that the ER occurs first, having the largest values of ΔR, and the FF and QF processes occur almost simultaneously at lower incident energies but the FF takes over QF at higher incident energies. In other words, the three processes occur in different time scales, QF competing with FF at lower incident energies.

ENTRANCE CHANNEL INDEPENDENCE IN THE DECAY OF 215Fr* NUCLEUS

2010 ◽  
Vol 25 (21n23) ◽  
pp. 2022-2023 ◽  
Author(s):  
MANOJ K. SHARMA ◽  
GUDVEEN SAWHNEY ◽  
SHEFALI KANWAR ◽  
RAJ K. GUPTA
Keyword(s):  
Compound Nucleus ◽  
Entrance Channel ◽  
Cluster Decay ◽  
Excitation Functions ◽  
Decay Model ◽  
Reaction Channels

The fusion-fission excitation functions for the decay of compound nucleus 215 Fr *, formed in 11 B +204 Pb and 18 O +197 Au reaction channels, are studied on the Dynamical Cluster-decay Model (DCM), showing entrance channel independence, in agreement with experiments, not invoking any quasi-fission (qf) process in either of the two channels.

ENTRANCE-CHANNEL EFFECTS IN THE DYNAMICAL CLUSTER-DECAY MODEL FOR THE DECAY OF HOT AND ROTATING COMPOUND NUCLEUS 48Cr AT ${\rm E}_{CN}^{*}\approx 60\, {\rm MeV}$

2006 ◽  
Vol 15 (03) ◽  
pp. 699-717 ◽  
Author(s):  
BIRBIKRAM SINGH ◽  
MANOJ K. SHARMA ◽  
RAJ K. GUPTA ◽  
WALTER GREINER
Keyword(s):  
Compound Nucleus ◽  
Cross Sections ◽  
Entrance Channel ◽  
Cluster Decay ◽  
Intermediate Mass ◽  
Excitation Energies ◽  
Decay Model ◽  
Independence Hypothesis ◽  
Channel Effects ◽  
Collective Clusterization

The entrance-channel effects in the decay of hot and rotating compound nucleus 48 Cr *, formed in symmetric 24 Mg +24 Mg and asymmetric 36 Ar +12 C reactions, are studied as collective clusterization process, for emissions of both the light particles (LPs) as well as the intermediate mass fragments (IMFs), with in the dynamical cluster-decay model (DCM). We find that the little differences observed in the decay of equilibrated compound nucleus 48 Cr *, formed in the two entrance channels with about the same excitation energy, are not in variance with the Bohr's independence hypothesis. In other words, the present study confirms the entrance-channel independence of the decay of compound nucleus 48 Cr * formed due to different target-projectile combinations with similar excitation energies. The collective clusterization process is shown to contain the complete structure of the measured fragment cross sections as well as average total kinetic energies.

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