INTERACTION OF VANADIUM WITH PROTONS OF ENERGIES UP TO 84 MEV

1963 ◽  
Vol 41 (9) ◽  
pp. 2194-2209 ◽  
Author(s):  
S. Hontzeas ◽  
L. Yaffe
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Heavy Particle ◽  
Particle Emission ◽  
Surface Absorption ◽  
Excitation Functions ◽  
Absorption Models ◽  
Comparison Of The Results ◽  
Bombarding Energy ◽  
Cross Section Distribution

Radiochemical techniques have been used to determine absolute excitation functions for 17 nuclides formed as spallation products from the irradiation of vanadium by protons of energy up to 84 Mev. The shape of the excitation functions and classical threshold calculations showed evidence of contribution of heavy-particle emission in the reactions of the type (p,3pxn), (p,5pxn), and (p,7pxn). The Barr method for analysis of the cross-section distribution was modified and applied at 60 and 80 Mev bombarding energies. The experimentally measured cross sections for 16 nuclides at 60 and 80 Mev bombarding energies were fitted to the four-parameter Rudstam equation σ (A,Z) = exp [PA−Q−R(Z−SA)2]. Comparison of the results obtained at 8 Mev bombarding energy with the predictions of the weak and strong absorption models showed better agreement with the predictions obtained by using the surface absorption Fernbach–Bjorklund potential.

STUDY OF ISOMERIC CROSS-SECTION RATIO AND PRE-EQUILIBRIUM FRACTION IN PROTON AND ALPHA PARTICLE INDUCED NUCLEAR REACTIONS ON 197Au

2012 ◽  
Vol 21 (06) ◽  
pp. 1250059 ◽  
Author(s):  
B. SATHEESH ◽  
M. M. MUSTHAFA ◽  
B. P. SINGH ◽  
R. PRASAD
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Nuclear Reactions ◽  
Energy Difference ◽  
Activation Technique ◽  
Cross Section Ratio ◽  
Excitation Functions ◽  
Section Ratio ◽  
Isomeric Cross Section Ratio ◽  
Equilibrium Emission

Excitation functions for the reactions 197 Au(p,n) 197g Hg and 197 Au(p,n) 197m Hg have been measured over the energy ranges from threshold up to 20 MeV using stacked foil activation technique. The isomeric cross-section ratio σm/(σm+σg) for the formation of 197g, m Hg was determined. The excitation functions and isomeric cross-section ratios were calculated for the reactions 197 Au(p,n) 197g,m Hg , 197 Au(p,2n) 196 Hg , 197 Au(p,3n) 195g,m Hg , 197 Au(p,4n) 194 Hg , 197 Au(p,5n) 193g,m Hg , 197 Au (α, n )200 Tl , 197 Au (α, 2n )199 Tl , 197 Au (α, 3n )198g,m Tl , 197 Au (α, 4n )197 Tl and 197 Au (α, 5n )196g,m Tl from reaction threshold up to 40 MeV for proton induced reactions and 80 MeV for alpha induced reactions. The results were compared with the theoretical cross-sections calculated by means of the code EMPIRE-II and with the available literature data, which makes use of the Hauser Feshbach model for the compound nuclear calculations and the exciton model for the pre-equilibrium emission part. The isomeric cross-section ratio is found to depend strongly on the relative spins of the isomeric and ground state, energy difference between the levels, presence of intermediate states and some dependence on decay modes and on the onset of pre-equilibrium emission.

scholarly journals Flavor-dependent radiative corrections in coherent elastic neutrino-nucleus scattering

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Oleksandr Tomalak ◽  
Pedro Machado ◽  
Vishvas Pandey ◽  
Ryan Plestid
Keyword(s):  
Standard Model ◽  
Cross Section ◽  
Cross Sections ◽  
Nuclear Physics ◽  
Heavy Particle ◽  
New Physics ◽  
Effective Field ◽  
Radiative Corrections ◽  
The Standard Model ◽  
Nucleus Scattering

Abstract We calculate coherent elastic neutrino-nucleus scattering cross sections on spin-0 nuclei (e.g. 40Ar and 28Si) at energies below 100 MeV within the Standard Model and account for all effects of permille size. We provide a complete error budget including uncertainties at nuclear, nucleon, hadronic, and quark levels separately as well as perturbative error. Our calculation starts from the four-fermion effective field theory to explicitly separate heavy-particle mediated corrections (which are absorbed by Wilson coefficients) from light-particle contributions. Electrons and muons running in loops introduce a non- trivial dependence on the momentum transfer due to their relatively light masses. These same loops, and those mediated by tau leptons, break the flavor universality because of mass-dependent electromagnetic radiative corrections. Nuclear physics uncertainties significantly cancel in flavor asymmetries resulting in subpercent relative errors. We find that for low neutrino energies, the cross section can be predicted with a relative precision that is competitive with neutrino-electron scattering. We highlight potentially useful applications of such a precise cross section prediction ranging from precision tests of the Standard Model, to searches for new physics and to the monitoring of nuclear reactors.

scholarly journals Cross Section Measurements in the 54Cr(p, ?)55Mn Reaction

1979 ◽  
Vol 32 (4) ◽  
pp. 335 ◽  
Author(s):  
R. J. Wilkinson ◽  
A S. R. Kennett ◽  
A Z. E. Switkowski ◽  
D. G. SargoodA and F. M. MannC
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Reaction Cross Section ◽  
Proton Energy ◽  
Gamma Ray ◽  
Reaction Cross ◽  
Model Calculations ◽  
Global Parameter ◽  
Dramatic Effect ◽  
Bombarding Energy

Cross sections for production of individual y rays in the 54Cr(p, y)55Mn reaction have been measured over the proton energy range 1�0-3�8 MeV. Gamma-ray yields are observed to fall by factors of between 5 and 10 at the crossing of the neutron threshold for a proton bombarding energy of 2�2 MeV. Statistical model calculations with global parameter sets successfully account for the dramatic effect of neutron competition on the (p, y) cross section, and at the same time correctly predict the 54Cr(p,n)54Mn reaction cross section.

scholarly journals CONSIDERATION OF THE IMPACT OF HIGH HARMONICS WHEN SELECTING THE CONDUCTOR CROSS-SECTIONS OF LINES OF OUTDOOR LIGHTING

2017 ◽  
Vol 60 (6) ◽  
pp. 544-557 ◽  
Author(s):  
V. B. Kozlovskaya ◽  
V. N. Kalechyts
Keyword(s):  
High Pressure ◽  
Cross Section ◽  
Cross Sections ◽  
Operating Mode ◽  
Correct Choice ◽  
Light Sources ◽  
High Harmonics ◽  
Phase Conductors ◽  
Comparison Of The Results ◽  
The Impact

The operating mode of the lighting line depends on the correct choice of conductor cross section. The magnitude of the cross section has an influence on the provision of the required voltage levels on the light sources. The choice of the conductor cross section has been fulfilled based on calculations of the operating mode of the standard line of outdoor lighting specified in the article. Luminaries with high pressure sodium lamps connected through electromagnetic ballasts were used as sources of light. When choosing the conductor cross section of light lines a number of simplifications are commonly used. Attention is paid to the choice of sections without such assumptions: the inductive resistance of conductors is taken into account; the power of the luminaire depends on the voltage level in it. Luminaries with high pressure sodium lamps are the sources of high harmonics. Three variants of calculation are demonstrated depending on the accounting (or non-accounting) of high odd harmonics. The methods of calculating the mode of the lighting line are also presented in the article. The calculation is performed with the aid of Mathcad software. Operating parameters for each phase of the line (i.e. voltage in the items of the scheme, power, currents, power, and voltage losses in all the sections) were determined. The diagrams of the voltage distribution at items of the lighting line for three variants of calculation are plotted for various sections of aluminum conductors. On this basis the choice of the optimum magnitude of the conductor cross section of the lighting line was made. The obtained results of different calculation variants are compared. The comparison of the results obtained with the use of various methods of calculation was made. The impact of high harmonics on the operating mode of the line under consideration has been analyzed. The presence of high harmonics causes an increase of voltage losses, the distortion of sinusoidal voltage. The current of neutral conductor is comparable with the current of phase conductors, besides, the harmonics multiple of 3 are of great importance as they influence on the magnitude of the current.

Nuclear Charge Dispersion in the Fission of 235U by Protons of Energy 20–85 MeV

1971 ◽  
Vol 49 (13) ◽  
pp. 2205-2216 ◽  
Author(s):  
G. B. Saha ◽  
I. Tomita ◽  
L. Yaffe
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Nuclear Charge ◽  
Fission Products ◽  
Mass Range ◽  
Dispersion Curves ◽  
Cross Section Data ◽  
Excitation Functions ◽  
Section Data ◽  
Good Agreement

Independent formation cross sections of 129Cs, 130Cs, 131Cs, 134Csm, 134Csm+g, 136Cs, 139Ce, and cumulative formation cross sections of 141Ce and 143Ce were obtained when 235U was caused to fission with protons of energies varying between 20 and 85 MeV. The energies at which the excitation functions reached their maxima were related to the neutron-to-proton ratio of the fission products. These were compared with other fissioning systems. Charge dispersion curves were obtained from the cross section data. The variation of (ZA − Zp) with energy, both in magnitude and in trend, agrees extremely well with predictions made by Saha and Yaffe for nuclides in this mass range. Calculations for Zp show that good agreement is obtained with the unchanged charge division hypothesis. An estimate has been made of the total number of neutrons emitted in fission at these energies.

scholarly journals STRUCTURAL EFFECTS IN THE NUCLIDE DISTRIBUTIONS OF THE RESIDUES OF HIGHLY EXCITED SYSTEMS

2004 ◽  
Vol 13 (01) ◽  
pp. 333-336 ◽  
Author(s):  
P. NAPOLITANI ◽  
F. REJMUND ◽  
L. TASSAN-GOT ◽  
M. V. RICCIARDI ◽  
A. KELIC ◽  
...  
Keyword(s):  
Cross Section ◽  
Production Cross Section ◽  
Production Cross ◽  
Particle Emission ◽  
Structural Effects ◽  
Level Densities ◽  
The Cross ◽  
Emission Threshold ◽  
Cross Section Distribution

New data from GSI on the production-cross-section for fragmentation of the systems 56 Fe+p and 136 Xe+p at 1 A GeV revealed the appearance of even-odd staggering in the cross-section distribution for chains of isotopes with given N-Z. The staggering is strongly enhanced for the chain N=Z, it reduces as the production moves away from the N=Z chain, and it reverses for the most neutron-rich odd-A residues. These phenomena, observed in the residues of rather violent reactions, are related to structural effects in the level-densities below the particle-emission threshold.

Ground-state and isomeric-state cross-sections for 92Mo(n,α)89Zr and 95Mo(n,p)95Nb reactions in the 13–15 MeV energy region

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Junhua Luo ◽  
Li Jiang
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Ground State ◽  
Nuclear Decay ◽  
Excitation Functions ◽  
Total Cross Sections ◽  
Γ Ray ◽  
Simulation Results ◽  
The Cross ◽  
Isomeric Ratios

Abstract The (n,α) and (n,p) cross-sections and their isomeric ratios (σ m /σ g ) were measured at 13–15 MeV for 92Mo and 95Mo by activation and off-line γ-ray spectrometry. The activated Mo samples combined with Al foils were used to obtain the cross-section values and the neutron flux, generated using the 3H(d,n)4He reaction. The cross-sections of the ground states were obtained using the metastable state absolute cross-sections and the residual nuclear decay rule. The excitation functions, total cross-sections, and isomeric ratios for the 92Mo(n,α)89m,gZr and 95Mo(n,p)95m,gNb reactions were calculated using the TALYS-1.95 software. 92Mo(n,α)89m + gZr and 95Mo(n,p)95m + gNb reaction excitation functions were obtained using the EMPIRE-3.2.3 package. These simulation results were compared with the corresponding experimental data and with the evaluated data from the ENDF/B-VIII.0, JEFF-3.3, CENDL-3, and ROSFOND libraries. Only partial agreements were observed.

The cross-sections and angular distributions of the D—D reactions between 150 and 450 keV

1954 ◽  
Vol 226 (1165) ◽  
pp. 206-216 ◽  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Deuteron Beam ◽  
Angular Distributions ◽  
Centre Of Mass ◽  
Mass System ◽  
Gas Target ◽  
Neutron Reaction ◽  
The Cross ◽  
Bombarding Energy

A thin gas target was used and the 3 He and 3 H particles from the reactions were counted in two proportional counters which were rotated to make angles between 20 and 135° (in the centre-of-mass system) with the incident deuteron beam. In contradiction to data previously published for this energy range, the angular distributions of the reactions are different, the asymmetry of the neutron-producing reaction being the greater. The total cross-section of the neutron reaction is greater than that of the proton reaction; the ratio of the cross-sections increases with bombarding energy.

Study of proton induced nuclear reactions on molybdenum: cross section measurements and theoretical calculations

2019 ◽  
Vol 108 (1) ◽  
pp. 1-9
Author(s):  
Alaa Elbinawi ◽  
Mogahed Al-abyad ◽  
Ibrahim Bashter ◽  
Usama Seddik ◽  
Ferenc Ditrói
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Nuclear Reactions ◽  
Theoretical Calculations ◽  
Experimental Results ◽  
Excitation Functions ◽  
Stacked Foil Technique ◽  
Theoretical Results ◽  
Production Conditions ◽  
Foil Technique

Abstract Excitation functions were measured by the activation method using the stacked-foil technique for the natMo(p,x)93(m+g),94m,g,95m,g,96(m+g),99mTc, 92m,95Nb reactions up to 18 MeV. The experimental results were compared with literature data and theoretical results from EMPIRE-3.2.2 code and TENDL. Special attention was paid to the 100Mo(p,2n)99mTc reaction which is very promising for the production of 99mTc at a cyclotron. In order to optimize the production conditions of some medically important Tc isotopes, the integral yields were estimated based on the measured cross sections.

Electron Irradiation Effects in Polyoxymethylene Crystals Grown Inside Trioxane Crystals

1971 ◽  
Vol 29 ◽  
pp. 78-79
Author(s):  
J. P. Colson ◽  
D. H. Reneker
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Detailed Examination ◽  
The Other ◽  
Electron Micrograph ◽  
Irradiation Effects ◽  
Threefold Axis ◽  
Typical Sample ◽  
Polymer Crystals ◽  
Chain Axis

Polyoxymethylene (POM) crystals grow inside trioxane crystals which have been irradiated and heated to a temperature slightly below their melting point. Figure 1 shows a low magnification electron micrograph of a group of such POM crystals. Detailed examination at higher magnification showed that three distinct types of POM crystals grew in a typical sample. The three types of POM crystals were distinguished by the direction that the polymer chain axis in each crystal made with respect to the threefold axis of the trioxane crystal. These polyoxymethylene crystals were described previously.At low magnifications the three types of polymer crystals appeared as slender rods. One type had a hexagonal cross section and the other two types had rectangular cross sections, that is, they were ribbonlike.

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