scholarly journals Measuring precise fusion cross sections using an 8T superconducting solenoid

2020 ◽  
Vol 232 ◽  
pp. 03003
Author(s):  
L. T. Bezzina ◽  
E. C. Simpson ◽  
D. J. Hinde ◽  
M. Dasgupta ◽  
I. P. Carter ◽  
...  
Keyword(s):  
Angular Distribution ◽  
Cross Sections ◽  
Laboratory Frame ◽  
Transmission Efficiency ◽  
Evaporation Residue ◽  
Angular Distributions ◽  
The Novel ◽  
Superconducting Solenoid ◽  
National University ◽  
Evaporation Residues

A novel fusion-evaporation residue separator based on a gas-filled superconducting solenoid has been developed at the Australian National University. Though the transmission efficiency of the solenoid is very high, precision cross sections measurements require this efficiency to be accurately known and vitally, requires knowledge of the angular distribution of the evaporation residues. We have developed a method to deduce the angular distribution of the evaporation residues from the laboratory-frame velocity distribution of the evaporation residues transmitted by the solenoid. The method will be discussed, focusing on benchmarking examples for 34S+89Y, where the angular distributions have been independently measured using a velocity filter (A. Mukherjee et al., Phys. Rev. C. 66, 034607 (2002)) . The establishment of this method now allows the novel solenoidal separator to be used to obtain reliable, precise fusion cross-sections.

COMPARISON OF THE FUSION-FISSION AND QUASIFISSION MECHANISMS IN HEAVY-ION COLLISIONS

2009 ◽  
Vol 18 (04) ◽  
pp. 841-849 ◽  
Author(s):  
AVAZBEK NASIROV ◽  
GIOVANNI FAZIO ◽  
GIORGIO GIARDINA ◽  
GIUSEPPE MANDAGLIO ◽  
MARINA MANGANARO ◽  
...  
Keyword(s):  
Cross Sections ◽  
Theoretical Method ◽  
Heavy Ion ◽  
Evaporation Residue ◽  
System Model ◽  
Complete Fusion ◽  
Dinuclear System ◽  
Ion Collisions ◽  
Partial Fusion ◽  
Evaporation Residues

The decrease of the evaporation residue yields in reactions with massive nuclei is explained by an increase of the competition between quasifission and complete fusion processes and by the decrease of the survival probability of the heated and rotating nuclei against fission along the de-excitation cascade of the compound nucleus. The experimental data on the yields of evaporation residue, fusion-fission and quasifission fragments in the 48 Ca + 154 Sm reaction are analyzed in the framework of the combined theoretical method based on the dinuclear system concept and advanced statistical model. The measured yields of evaporation residues of the 48 Ca + 154 Sm reaction have been well reproduced and yields of fission fragments were analyzed using the partial fusion and quasifission cross sections calculated in the dinuclear system model. Such a way of calculation is used to find optimal conditions for the synthesis of the new element Z = 120 (A = 302) by studying the excitation functions of evaporation residues of the 54 Cr + 248 Cm , 58 Fe + 244 Pu , and 64 Ni + 238 U reactions. Our estimations show that the 54 Cr + 248 Cm reaction is preferable in comparison with the two others.

COLD FUSION REACTIONS USING NEUTRON-RICH PROJECTILES

2013 ◽  
Vol 22 (08) ◽  
pp. 1350061 ◽  
Author(s):  
A. SULAKSONO
Keyword(s):  
Cross Section ◽  
Compound Nucleus ◽  
Cross Sections ◽  
Estimation Method ◽  
Cold Fusion ◽  
Evaporation Residue ◽  
Fusion Reactions ◽  
Fusion Barrier ◽  
The Cross ◽  
Evaporation Residues

This paper studies the formation cross-sections of super heavy (SH) nuclei in some cold fusion reactions of radioactive neutron-rich projectiles with double-magic 208 Pb target. In this study, the cross-sections of capture, fusion and evaporation residues in one- and two-neutron (1n and 2n) channels are calculated by using neutron-rich Fe , Ni and Zn projectiles are compared to the cross-sections calculated using stable Fe , Ni and Zn projectiles. The heights of fusion barrier and their positions in all reactions considered in this study are also compared to the heights and positions calculated using the estimation method proposed by Dutt and Puri. For cold fusion reactions with stable Fe , Ni and Zn projectiles, the heights of fusion barrier and the cross-sections of evaporation residues in 1n and 2n channels are compared to their corresponding experimental data. In general, for reactions using projectiles with the same proton number, the neutron-rich projectile is found to yield relatively-heavier mass of SH nucleus and larger evaporation residue cross-section, compared to those of the corresponding stable projectiles. However, in certain reactions, the cross-sections of neutron-rich projectile can be slightly larger or slightly smaller than that of the corresponding stable projectile. This behavior is highly affected by the charge of projectile and the fission barrier of the formed compound nucleus (CN). In addition, the 292114 is found to be the heaviest compound nucleus formed in cold fusion reaction by using neutron-rich nuclei as the projectile, but the cross-section of evaporation residue in one-neutron channel is still around few pico barns (pb).

THE SCATTERING OF PROTONS ON 7Li, 9Be, AND 12C AT 100 MEV

1966 ◽  
Vol 44 (12) ◽  
pp. 2961-2971 ◽  
Author(s):  
S. K. Mark ◽  
P. M. Portner ◽  
R. B. Moore
Keyword(s):  
Angular Distribution ◽  
Inelastic Scattering ◽  
Cross Sections ◽  
Differential Cross ◽  
Target Nucleus ◽  
Energy Region ◽  
Angular Distributions ◽  
Angular Range ◽  
Existing Data ◽  
Octupole Excitation

Elastic and inelastic scattering of protons on 7Li, 9Be, and 12C have been studied, using the 100-MeV proton beam from the McGill synchrocyclotron. Differential cross sections for the various groups of scattered protons were measured over an angular range of 5° to 90° (lab). For proton groups resulting from a quadrupole excitation in the target nucleus, the angular distribution was found to increase at scattering angles less than 10°. Angular distributions corresponding to an octupole excitation were observed to decrease at small angles. The results have been compared with existing data in this energy region.

THE ANGULAR DISTRIBUTION AND YIELD OF THE REACTION F19(p, α0)O16

1957 ◽  
Vol 35 (2) ◽  
pp. 155-167 ◽  
Author(s):  
R. L. Clarke ◽  
E. B. Paul
Keyword(s):  
Angular Distribution ◽  
Least Squares ◽  
Cross Sections ◽  
Legendre Polynomial ◽  
Ground State ◽  
Energy Region ◽  
Alpha Particles ◽  
Angular Distributions ◽  
Method Of Least Squares ◽  
Channel Spin

The yield of the ground state alpha particles from the F19(p, α0)O16 reaction has been studied from an energy of 1.3 Mev. to 2.7 Mev. The observed angular distributions were analyzed in terms of a Legendre polynomial expansion by the method of least squares. Six resonances were found in the energy region studied, at bombarding energies of 1.358 Mev., 1.709 Mev., 1.853 Mev., 2.11 Mev., 2.31 Mev., and 2.58 Mev. The widths and peak cross sections of these resonances are respectively: (54 ± 10 kev., 46 ± 5 mb.), (140 ± 5 kev., 55 ± 6 mb.), (132 ± 5 kev., 77 ± 8 mb.), (75 ± 25 kev., 10 ± 2 mb.), (80 ± 25 kev., 32 ± 5 mb.), and (300 ± 25 kev., 51 ± 10 mb.). Their spins, parities, channel spin mixtures, and partial widths are discussed.

APPEARANCE OF FAST-FISSION AND QUASI-FISSION IN REACTIONS WITH MASSIVE NUCLEI

2005 ◽  
Vol 20 (06) ◽  
pp. 391-405 ◽  
Author(s):  
GIOVANNI FAZIO ◽  
GIORGIO GIARDINA ◽  
GIUSEPPE MANDAGLIO ◽  
FRANCIS HANAPPE ◽  
AKHTAM I. MUMINOV ◽  
...  
Keyword(s):  
Experimental Data ◽  
Reaction Mechanism ◽  
Excitation Function ◽  
Cross Sections ◽  
Neutron Emission ◽  
Evaporation Residue ◽  
Dinuclear System ◽  
Total Evaporation ◽  
Fast Fission ◽  
Evaporation Residues

The experimental data on the capture and evaporation residue cross-sections obtained in the 48 Ca +208 Pb reaction were analyzed in the framework of the dynamical model based on the dinuclear system concept and advanced statistical method to clarify the reaction mechanism. The experimental excitation function of the capture reactions was decomposed into contributions of the fusion–fission, quasifission and fast-fission processes. Total evaporation residues and ones after neutron emission were only calculated and compared with the available experimental data.

Studies of nuclear collisions involving 8 MeV deuterons by the photographic method III. Angular distribution of the charged particles produced by the bombardment of hydrogen and deuterium

1951 ◽  
Vol 209 (1099) ◽  
pp. 489-501 ◽  
Keyword(s):  
Angular Distribution ◽  
Cross Section ◽  
Cross Sections ◽  
Charged Particles ◽  
Elastic Collision ◽  
Angular Distributions ◽  
Centre Of Mass ◽  
Mass System ◽  
Nuclear Collisions ◽  
Nuclear Processes

Apparatus previously described has been used to study the angular distribution of the charged particles from nuclear processes initiated by 8 MeV deuterons. The experimental technique and the method of obtaining relative values of the yield at different angles in the centre-of-mass system are described. Results of measurements on the elastic collision of deuterons with protons are given, together with an account of the method for obtaining absolute values of cross-sections from the relative values, using the known cross-section for this process measured by other experimenters. Angular distributions obtained for deuterons elastically scattered by deuterons, and for protons from the reaction 2 H ( d , p ) 3 H, are produced, and their interpretation discussed.

A Discussion on photoelectron spectroscopy - Angular distributions of photoelectrons and partial photoionization cross-sections

1970 ◽  
Vol 268 (1184) ◽  
pp. 141-146 ◽  
Keyword(s):  
Angular Distribution ◽  
Cross Sections ◽  
Photoelectron Spectroscopy ◽  
Ionization Potentials ◽  
Experimental Arrangement ◽  
Angular Distributions ◽  
Asymmetry Coefficient ◽  
Vibrational States ◽  
The Asymmetry

An experimental arrangement is given for measuring the angular distribution of photoelectrons. The asymmetry coefficient B is found to be 0.3 for Ar, and 0.3 and 0.12 for N2 at 584 A when the residual ion core is left in its X2z and A2II states, respectively. The partial photoionization cross-sections are given for O2 at 186, 209, 247, 330, and 460 A. New ionization potentials for O2 are found at 23.5, 24.6 and 27.3 eV ± 0.3 eV. The effects of autoionizing transitions on the population of vibrational states of N+2 are illustrated.

scholarly journals New 23Na evaluation in the resolved resonance range taking into account both differential and double differential experiments

2020 ◽  
Vol 239 ◽  
pp. 11006
Author(s):  
Pierre Tamagno ◽  
Pascal Archier ◽  
Cyrille De Saint Jean ◽  
Gilles Noguère
Keyword(s):  
Angular Distribution ◽  
Cross Sections ◽  
Evaluation Process ◽  
Nuclear Data ◽  
Angular Distributions ◽  
Quantum Numbers ◽  
Nuclear Data Library ◽  
Critical Facilities ◽  
Elastic Angular Distribution ◽  
Level Of Agreement

In 2012 CEA produced a entire new evaluation of sodium nuclear data for the release of the JEFF-3.2 evaluated nuclear data library. During the evaluation process performed with the CONRAD code, several differential measurements (total and discrete inelastic cross-sections) have been used. However double differential data (elastic angular distribution) that were yet available in the EXFOR database were not incorporated in the analysis at that time. The experimental elastic angular distribution were discarded because of it was impossible to obtain a good agreement for both angle-integrated cross-sections and double differential ones. The underlying cause of this disagreement is expected to be due to the attribution of quantum numbers to resonance and related channel amplitudes. Indeed these numbers are imposed during the analysis but impact differently angular distributions and angle-integrated cross-sections. An automated search for an accurate set of quantum numbers has been implemented in order to produce a reliable quantum numbers set. In this paper we present a new evaluation of Na-23 taking into account both differential and double differential measurements. The analysis performed with the CONRAD code reached the level of agreement with experimental data for the total and inelastic cross-sections but this time with a significant improvement for the elastic angular distributions. This new evaluation produced in the ENDF-6 format has then been tested and validated on critical facilities calculation (MASURCA and ZPPR) in different configurations (nominal and voided) in order to assess its performances.

scholarly journals ω AND η MESON PRODUCTION IN p+p REACTIONS AT Ekin = 3.5 GeV

2011 ◽  
Vol 26 (03n04) ◽  
pp. 694-696 ◽  
Author(s):  
◽  
KHALED TEILAB
Keyword(s):  
Angular Distribution ◽  
Kinetic Energy ◽  
Cross Sections ◽  
Energy Production ◽  
Production Cross ◽  
Meson Production ◽  
Angular Distributions ◽  
Exclusive Production ◽  
Relative Contribution ◽  
Dalitz Plots

We report on the exclusive production of ω and η mesons in p + p reactions at 3.5 GeV beam kinetic energy. Production cross sections, angular distributions and Dalitz plots of both mesons were determined. Moreover, the relative contribution of the N(1535) resonance in η production at this energy was evaluated. We conclude that η mesons produced via N(1535) exihibit an isotropic angular distribution, whereas those produced directly show a strong anisotropic distribition. ω mesons show a slightly anisotropic angular distribition.

Electron Scattering in Solids

1990 ◽  
Vol 48 (2) ◽  
pp. 4-5
Author(s):  
Ryuichi Shimizu ◽  
Ze-Jun Ding
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Angular Distribution ◽  
Elastic Scattering ◽  
Electron Scattering ◽  
Cross Sections ◽  
Expansion Method ◽  
Electron Excitation ◽  
Partial Wave Expansion ◽  
Backscattered Electrons

Monte Carlo simulation has been becoming most powerful tool to describe the electron scattering in solids, leading to more comprehensive understanding of the complicated mechanism of generation of various types of signals for microbeam analysis.The present paper proposes a practical model for the Monte Carlo simulation of scattering processes of a penetrating electron and the generation of the slow secondaries in solids. The model is based on the combined use of Gryzinski’s inner-shell electron excitation function and the dielectric function for taking into account the valence electron contribution in inelastic scattering processes, while the cross-sections derived by partial wave expansion method are used for describing elastic scattering processes. An improvement of the use of this elastic scattering cross-section can be seen in the success to describe the anisotropy of angular distribution of elastically backscattered electrons from Au in low energy region, shown in Fig.l. Fig.l(a) shows the elastic cross-sections of 600 eV electron for single Au-atom, clearly indicating that the angular distribution is no more smooth as expected from Rutherford scattering formula, but has the socalled lobes appearing at the large scattering angle.

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