scholarly journals FISSION CROSS SECTION IN THE SYNTHESIS OF THE 264Rf NUCLEUS VIA 26Mg+238U COMBINATION

2018 ◽  
Vol 127 (1A) ◽  
pp. 95
Author(s):  
Trần Viết Nhân Hào
Keyword(s):  
Mass Distribution ◽  
Cross Section ◽  
Compound Nucleus ◽  
Transfer Reaction ◽  
Fission Cross Section ◽  
Transfer Reactions ◽  
Heavy Nuclei ◽  
Fission Process ◽  
Rich Side

Our understanding of the fission mechanism has been still limited up to date, especially, for mass distribution of heavy nuclei or actinide ones. Since the heavy isotopes on the neutron-rich side of the nuclear chart cannot be accessed via capture reactions, it is thought that the mechanism can be studied via compound nuclei produced by multi-nucleon transfer reactions. In which, the fission process should be understood. In this report we mention the role of the transfer reaction <sup>26</sup>Mg + <sup>238</sup>U and an estimation of the cross section of the fission leds by the compound nucleus, <sup>264</sup>Rf.

scholarly journals Role of Polar vs Non-polar Configurations in the Decay of 268Sg* Compound Nucleus Within the Skyrme Energy Density Formalism

2021 ◽  
Vol 9 (1) ◽  
pp. 61-66
Author(s):  
Rajni Mittal ◽  
Kirandeep Sandhu ◽  
M. K. Sharma
Keyword(s):  
Experimental Data ◽  
Energy Density ◽  
Cross Section ◽  
Compound Nucleus ◽  
Cross Sections ◽  
Fission Cross Section ◽  
Cluster Decay ◽  
The Impact ◽  
Adequate Agreement

The effect of polar and non-polar configurations is investigated in the decay of 268Sg* compound nucleus formed via spherical projectile (30Si) and prolate deformed target (238U) using the dynamical cluster decay model. The SSK and GSkI skyrme forces are used to investigate the impact of polar and nonpolar (equatorial) configurations on the preformation probability P0 and consequently on the fission cross-sections of 268Sg* nucleus. For non-polar configuration some secondary peaks corresponding to magic shells Z=28 and N=50 are observed, whose magnitude is significantly suppressed for the polar counterpart. The effect of polar and non-polar configurations is further analyzed in reference to barrier lowering parameter ΔVB. The calculated fission cross-section find adequate agreement with experimental data for chosen set of skyrme forces.

MEASURING CAPTURE CROSS SECTIONS FOR HEAVY-ELEMENT PRODUCTION

2004 ◽  
Vol 13 (01) ◽  
pp. 293-300
Author(s):  
NEIL ROWLEY ◽  
NABILA GRAR
Keyword(s):  
Cross Section ◽  
Compound Nucleus ◽  
Cross Sections ◽  
Reaction Path ◽  
Superheavy Element ◽  
Evaporation Residue ◽  
Capture Cross ◽  
Total Capture ◽  
Capture Cross Sections

The creation of the nucleus of a superheavy element follows an extremely complex reaction path starting with the crossing of an external potential barrier (or distribution of barriers). This is followed by the evolution towards an equilibrated compound nucleus, which takes place in competition with pre-compound-nucleus fission (quasi-fission). Once formed the equilibrated compound nucleus must still survive against true fusion to yield a relatively long-lived evaporation residue. Much of this path is poorly understood, though recently, progress has been made on the role of the entrance-channel in quasi-fission. This will be briefly reported and a method proposed to measure the total capture cross section for such systems directly.

CALCULATIONS OF CROSS SECTIONS FOR THE SYNTHESIS OF SUPER-HEAVY NUCLEI IN COLD FUSION REACTIONS

2004 ◽  
Vol 13 (01) ◽  
pp. 261-267 ◽  
Author(s):  
W. J. ŚWIATECKI ◽  
K. SIWEK-WILCZYŃSKA ◽  
J. WILCZYŃSKI
Keyword(s):  
Cross Section ◽  
Compound Nucleus ◽  
Cross Sections ◽  
Free Parameter ◽  
Cold Fusion ◽  
One Dimension ◽  
Brownian Diffusion ◽  
Heavy Nuclei ◽  
Fusion Reactions ◽  
Super Heavy Nuclei

The fusion cross sections are considered to be given by the product of three factors: the cross section to overcome the Coulomb barrier, the probability for the resulting system to reach the compound nucleus configuration by diffusion, and the probability for the compound nucleus to survive fission. The first and third factors are treated by more or less conventional equations, and the second by Brownian diffusion in one dimension. Adjusting one free parameter in the theory one can reproduce the twelve measured cross sections to within a factor of two.

scholarly journals Geometry of ultraperipheral nuclear collisions

2019 ◽  
Vol 34 (12) ◽  
pp. 1950068 ◽  
Author(s):  
I. M. Dremin
Keyword(s):  
Cross Section ◽  
Relative Role ◽  
Heavy Nuclei ◽  
Interior Space ◽  
Strong Magnetic Fields ◽  
Exclusive Production ◽  
Nuclear Collisions ◽  
Two Photon ◽  
Role Of Light

It is advocated that geometry of the interaction region of two heavy nuclei colliding at large impact parameters is important for the relative role of light-by-light scattering and QCD-initiated processes. Exclusive production of resonances is possible by dense electromagnetic fields in the interior space between the nuclei. The cross-section of the two-photon processes is evaluated and some examples are considered. It is speculated that the exclusive production of [Formula: see text]-mesons by “two-photon” processes forbidden by the Landau–Yang rule may be allowed within strong magnetic fields due to odd number of photons becoming involved.

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.

Oxygen K near edge structures studied with multiple scattering calculations

1988 ◽  
Vol 46 ◽  
pp. 504-505
Author(s):  
Xudong Weng ◽  
Peter Rez
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Partial Cross Section ◽  
Energy Window ◽  
Edge Structure ◽  
Fine Structures ◽  
Hydrogenic Model ◽  
Electron Energy Loss ◽  
Quantitative Chemical

In electron energy loss spectroscopy, quantitative chemical microanalysis is performed by comparison of the intensity under a specific inner shell edge with the corresponding partial cross section. There are two commonly used models for calculations of atomic partial cross sections, the hydrogenic model and the Hartree-Slater model. Partial cross sections could also be measured from standards of known compositions. These partial cross sections are complicated by variations in the edge shapes, such as the near edge structure (ELNES) and extended fine structures (ELEXFS). The role of these solid state effects in the partial cross sections, and the transferability of the partial cross sections from material to material, has yet to be fully explored. In this work, we consider the oxygen K edge in several oxides as oxygen is present in many materials. Since the energy window of interest is in the range of 20-100 eV, we limit ourselves to the near edge structures.

EVAPORATION RESIDUE AND FISSION CROSS-SECTION FOR THE SYSTEM : 40Ar + 110Pd

1980 ◽  
Vol 41 (C10) ◽  
pp. C10-234-C10-238 ◽  
Author(s):  
C. Cabot ◽  
H. Gauvin ◽  
Y. Le Beyec ◽  
H. Delagrange ◽  
J. P. Dufour ◽  
...  
Keyword(s):  
Cross Section ◽  
Fission Cross Section ◽  
Evaporation Residue

Exploring Baryon Rich Matter with Heavy-Ion Collisions

2019 ◽  
Vol 64 (7) ◽  
pp. 583 ◽  
Author(s):  
S. Harabasz
Keyword(s):  
Center Of Mass ◽  
Heavy Ion ◽  
State Density ◽  
Heavy Nuclei ◽  
First Order ◽  
Center Of Mass Energy ◽  
Ion Collisions ◽  
Deconfinement Phase Transition ◽  
Ground State Density

Collisions of heavy nuclei at (ultra-)relativistic energies provide a fascinating opportunity to re-create various forms of matter in the laboratory. For a short extent of time (10-22 s), matter under extreme conditions of temperature and density can exist. In dedicated experiments, one explores the microscopic structure of strongly interacting matter and its phase diagram. In heavy-ion reactions at SIS18 collision energies, matter is substantially compressed (2–3 times ground-state density), while moderate temperatures are reached (T < 70 MeV). The conditions closely resemble those that prevail, e.g., in neutron star mergers. Matter under such conditions is currently being studied at the High Acceptance DiElecton Spectrometer (HADES). Important topics of the research program are the mechanisms of strangeness production, the emissivity of matter, and the role of baryonic resonances herein. In this contribution, we will focus on the important experimental results obtained by HADES in Au+Au collisions at 2.4 GeV center-of-mass energy. We will also present perspectives for future experiments with HADES and CBM at SIS100, where higher beam energies and intensities will allow for the studies of the first-order deconfinement phase transition and its critical endpoint.

Nonclassical oxygen atom transfer reactions of an eight-coordinate dioxomolybdenum(vi) complex

2021 ◽  
Author(s):  
Leila G. Ranis ◽  
Jacqueline Gianino ◽  
Justin M. Hoffman ◽  
Seth N. Brown
Keyword(s):  
Oxygen Atom ◽  
Transfer Reaction ◽  
Transfer Reactions ◽  
Atom Transfer ◽  
Oxygen Atom Transfer ◽  
Oxygen Atom Transfer Reactions ◽  
Atom Transfer Reactions ◽  
Oxygen Atoms

Eight-coordinate MoO2(DOPOQ)2 can donate two oxygen atoms to substrates such as phosphines in a four-electron nonclassical oxygen atom transfer reaction.

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