States in 152Sm populated by the (t,α) reaction

1977 ◽  
Vol 55 (13) ◽  
pp. 1137-1144 ◽  
Author(s):  
C. R. Hirning ◽  
D. G. Burke
Keyword(s):  
Cross Sections ◽  
Attenuation Factor ◽  
Matrix Elements ◽  
Coriolis Coupling ◽  
Reaction Products ◽  
Plane Detector ◽  
Scientific Laboratory ◽  
Coupling Calculation ◽  
Good Agreement ◽  
Focal Plane Detector

Levels in the deformed even–even nucleus 152Sm have been populated by the (t,α) reaction using beams of 15 MeV tritons from the model FN tandem Van de Graaff accelerator at the Los Alamos Scientific Laboratory. For the initial experiments in the series the reaction products were analyzed in an Elbek magnetic spectrograph and detected with nuclear emulsions. Those done later made use of the Q3D magnetic spectrometer and helical-cathode focal plane detector. On the basis of levels observed in adjacent odd-Z nuclei and some previous (α,2nγ) results, a rotational band built on the Kπ = 5−, 5/2+[413] + 5/2−[532] two-quasiparticle state has been identified. A Coriolis coupling calculation has been done, which gives good agreement with experimental energies and cross sections when an attenuation factor of 0.31 is used for the Coriolis matrix elements.

scholarly journals Next-to-leading-order study of J/ψ angular distributions in e+e− → J/ψ + ηc, χcJ at $$ \sqrt{s} $$ ≈ 10.6 GeV

2021 ◽  
Vol 2021 (9) ◽  
Author(s):  
Zhan Sun
Keyword(s):  
Cross Sections ◽  
Charm Quark ◽  
Experimental Result ◽  
Angular Distributions ◽  
Matrix Elements ◽  
Leading Order ◽  
Charm Quark Mass ◽  
Qcd Factorization ◽  
Nonrelativistic Qcd ◽  
Good Agreement

Abstract In this paper, we present a detailed next-to-leading-order (NLO) study of J/ψ angular distributions in e+e−→ J/ψ + ηc, χcJ (J = 0, 1, 2) within the nonrelativistic QCD factorization (NRQCD). The numerical NLO expressions for total and differential cross sections, i.e., $$ \frac{d\sigma}{d\cos \theta } $$ dσ d cos θ = A + B cos2θ, are both derived. With the inclusion of the newly-calculated QCD corrections to A and B, the αθ (= B/A) parameters in J/ψ + χc0 and J/ψ + χc1 are moderately enhanced, while the magnitude of αθJ/ψ+χc2 is significantly reduced; regarding the production of J/ψ + ηc, the αθ value remains unchanged. By comparing with experiment, we find the predicted αθJ/ψ+ηc is in good agreement with the Belle measurement; however, αθJ/ψ+χc0 is still totally incompatible with the experimental result, and this discrepancy seems to hardly be cured by proper choices of the charm-quark mass, the renormalization scale, and the NRQCD matrix elements.

Odd Proton States in 165Tm, 167Tm, 169Tm, and 171Tm

1974 ◽  
Vol 52 (21) ◽  
pp. 2108-2126 ◽  
Author(s):  
H. C. Cheung ◽  
D. G. Burke ◽  
G. Løvhøiden
Keyword(s):  
Proton Transfer ◽  
Nuclear Structure ◽  
Cross Sections ◽  
Quadrupole Deformation ◽  
Angular Distributions ◽  
Coriolis Coupling ◽  
Reaction Products ◽  
Structure Factors ◽  
Nilsson Model ◽  
Photographic Emulsions

Proton states in the odd mass isotopes 165Tm, 167Tm, 169Tm, and 171Tm have been studied using (3He, d) and (α, t) reactions with 24 MeV 3He and 27 MeV 4He beams. The reaction products were analyzed with a magnetic spectrograph and detected with photographic emulsions, giving a resolution (FWHM) of 16–18 keV. The proton transfer l values were determined from (3He, d) angular distributions and from the ratios of (3He, d) and (α, t) cross sections. Nuclear structure factors, extracted using DWBA cross sections, were compared to those predicted by the Nilsson model with pairing corrections and Coriolis coupling included. Most of the previous assignments for low lying proton states have been confirmed, and several new ones were made. It is shown that the energy systematics of the intrinsic proton states cannot be attributed to variations in the quadrupole deformation, ε2, but can be explained by a small monotonic variation in the hexadecapole deformation, ε4.

A study of levels in 155Dy using the (d,t) and (3He,α) reactions

1976 ◽  
Vol 54 (12) ◽  
pp. 1258-1273 ◽  
Author(s):  
O. Straume ◽  
D. G. Burke ◽  
T. F. Thorsteinsen
Keyword(s):  
Nuclear Structure ◽  
Cross Sections ◽  
Negative Parity ◽  
Positive Parity ◽  
Angular Distributions ◽  
Coriolis Coupling ◽  
Reaction Products ◽  
Nilsson Model ◽  
Photographic Emulsions ◽  
Peak Widths

The (d,t) and (3He, α) reactions on a target of 156Dy have been used to study the nuclear structure of 155Dy. Beams of 15 MeV deuterons and 24 MeV 3He were obtained from the McMaster University FN tandem Van de Graaff accelerator. The reaction products were analyzed with an Enge-type magnetic spectrograph and detected in photographic emulsions. The (d,t) reaction was studied at 15 angles with typical peak widths (FWHM) of ~ 6 keV and (3He,α) exposures were made at 5 angles with peak widths of ~ 18 keV. The (d,t) angular distributions and ratios of the (3He,α) and (d,t) cross sections were used to determine l values for a number of transitions. It is found that the positive parity states can be described in terms of the Nilsson model when Coriolis coupling is included while for the negative parity states only the gross features are well-described this way.

scholarly journals The nuclear matrix elements of 0νββ decay and the NUMEN project at INFN-LNS

2018 ◽  
Vol 194 ◽  
pp. 02001 ◽  
Author(s):  
D. Carbone ◽  
F. Cappuzzello ◽  
C. Agodi ◽  
M. Cavallaro ◽  
L. Acosta ◽  
...  
Keyword(s):  
Cross Sections ◽  
Nuclear Matrix ◽  
Theoretical Models ◽  
Heavy Ion ◽  
Double Beta Decay ◽  
Matrix Elements ◽  
Reaction Products ◽  
Structure Information ◽  
Double Charge Exchange ◽  
Double Charge

The goal of NUMEN project is to access experimentally driven information on Nuclear Matrix Elements (NME) involved in the neutrinoless double beta decay (0νββ), by high-accuracy measurements of the cross sections of Heavy Ion (HI) induced Double Charge Exchange (DCE) reactions. The knowledge of the nuclear matrix elements is crucial to infer the neutrino average masses from the possible measurement of the half-life of 00νββ decay and to compare experiments on different isotopes. In particular, the (18O, 18Ne) and (20Ne, 20O) reactions are performed as tools for β+β+ and β-β- decays, respectively. The experiments are performed at INFN - Laboratory Nazionali del Sud (LNS) in Catania using the Superconducting Cyclotron (CS) to accelerate the beams and the MAGNEX magnetic spectrometer to detect the reaction products. The measured cross sections are very low, limiting the present exploration to few selected isotopes of interest in the context of typically low-yield experimental runs. In order to make feasible a systematic study of all the candidate nuclei, a major upgrade of the LNS facility is foreseen to increase the experimental yield of about two orders of magnitude. To this purpose, frontier technologies are going to be developed for both the accelerator and the detection systems. In parallel, advanced theoretical models will be developed to extract the nuclear structure information from the measured cross sections.

scholarly journals Photoproduction of mesons and Compton scattering on the proton: Selected results from the A2 Collaboration at MAMI

2020 ◽  
Vol 241 ◽  
pp. 01017
Author(s):  
Vahe Sokhoyan
Keyword(s):  
Compton Scattering ◽  
High Precision ◽  
Cross Sections ◽  
Final States ◽  
Photon Beams ◽  
Accelerator Facility ◽  
Crystal Ball ◽  
Plane Detector ◽  
Baryon Resonances ◽  
Focal Plane Detector

The A2 Collaboration performs a manifold research program using real photons in the Crystal Ball/TAPS experiment at the MAMI accelerator facility in Mainz. The experiments take advantage of high- intensity unpolarized, linearly or circularly polarized photon beams, and unpolarized or polarized targets. The detector setup provides almost complete coverage in solid angle and is well suited for the detection of multi particle final states. In order to probe the internal structure of the nucleon, the spectrum of baryon resonances is studied via measurements of unpolarized cross sections and various polarization observables in single and double meson photoproduction. The program aiming to determine the scalar and spin polarizabilities of the nucleons with high precision is performed with the Compton scattering experiments. In 2017, the focal plane detector used in the tagging system of the Crystal Ball/TAPS experiment was completely renewed, allowing new measurements with unprecedentedly high precision. This paper presents recent selected results from the A2 Collaboration at MAMI.

Fast-neutron-scattering cross sections in soft nuclei: 56Fe

1994 ◽  
Vol 72 (3-4) ◽  
pp. 162-168
Author(s):  
R. Cabezas ◽  
J. Lubian
Keyword(s):  
Experimental Data ◽  
Energy Range ◽  
Neutron Scattering ◽  
Fast Neutron ◽  
Cross Sections ◽  
Matrix Elements ◽  
Total Cross Sections ◽  
Coupled Channel ◽  
Scattering Cross Sections ◽  
Good Agreement

The neutron elastic, inelastic, and total cross sections in 56Fe are calculated in the energy range 1–5 MeV using the coupled-channel method and statistical Hauser–Feshbach theory. Reduced matrix elements for coupled-channel calculations were computed in the frame of the Davydov–Chaban model (DCM) including nonaxial hexadecapole modes. The DCM calculations are compared with those using the harmonic vibrational model and we prove that the first model is appropriate for this nucleus. Good agreement with experimental data is reached.

28Si + 28Si elastic scattering at energies above the Coulomb barrier

1988 ◽  
Vol 66 (9) ◽  
pp. 813-817 ◽  
Author(s):  
Ashok Kumar ◽  
B. B. Srivastava
Keyword(s):  
Elastic Scattering ◽  
Cross Sections ◽  
Simple Procedure ◽  
Matrix Elements ◽  
Nucleon Potential ◽  
Generator Coordinate ◽  
Group Methods ◽  
The Matrix ◽  
Sharp Cutoff ◽  
Good Agreement

A relatively simple procedure has been used to calculate the differential cross sections for 28Si + 28Si elastic scattering at Elab = 67, 74, 77, and 120 MeV. The nuclear interactions have been calculated microscopically using the equivalence relation between the matrix elements of the generator coordinate and the resonating group methods from the two-nucleon potential, which explains the two-nucleon data fairly well. The absorption effects due to the opening of the nonelastic channels are taken into account approximately by the classical sharp cutoff of partial waves. The calculated results are in quite good agreement with the available experimental data at most of these energies.

COMPUTER MODELING OF CHEMICAL EQUILIBRIUMS IN WO3–H2O SYSTEM

2017 ◽  
pp. 35-48 ◽  
Author(s):  
V.P. Bondarenko ◽  
O.O. Matviichuk
Keyword(s):  
Transition Temperature ◽  
Gas Phase ◽  
Single Phase ◽  
Reference Data ◽  
Maximum Amount ◽  
Reaction Products ◽  
Influence Of Temperature ◽  
Equilibrium Chemical ◽  
Program Data ◽  
Good Agreement

Detail investigation of equilibrium chemical reactions in WO3–H2O system using computer program FacktSage with the aim to establish influence of temperature and quantity of water on formation of compounds of H2WO4 and WO2(OH)2 as well as concomitant them compounds, evaporation products, decomposition and dissociation, that are contained in the program data base were carried out. Calculations in the temperature range from 100 to 3000 °С were carried out. The amount moles of water added to 1 mole of WO3 was varied from 0 to 27. It is found that the obtained data by the melting and evaporation temperatures of single-phase WO3 are in good agreement with the reference data and provide additionally detailed information on the composition of the gas phase. It was shown that under heating of 1 mole single-phase WO3 up to 3000 °С the predominant oxide that exist in gaseous phase is (WO3)2. Reactions of it formation from other oxides ((WO3)3 and (WO3)4) were proposed. It was established that compound H2WO4 is stable and it is decomposed on WO3 and H2O under 121 °C. Tungsten Oxide Hydrate WO2(OH)2 first appears under 400 °С and exists up to 3000 °С. Increasing quantity of Н2О in system leads to decreasing transition temperature of WO3 into both liquid and gaseous phases. It was established that adding to 1 mole WO3 26 mole H2O maximum amount (0,9044–0,9171 mole) WO2(OH)2 under temperatures 1400–1600 °С can be obtained, wherein the melting stage of WO3 is omitted. Obtained data also allowed to state that that from 121 till 400 °С WO3–Н2O the section in the О–W–H ternary system is partially quasi-binary because under these temperatures in the system only WO3 and Н2O are present. Under higher temperatures WO3–Н2O section becomes not quasi-binary since in the reaction products WO3 with Н2O except WO3 and Н2O, there are significant amounts of WO2(OH)2, (WO3)2, (WO3)3, (WO3)4 and a small amount of atoms and other compounds. Bibl. 12, Fig. 6, Tab. 5.

Analysis of Reinforced Concrete Culvert considering Concrete Creep and Shrinkage

1996 ◽  
Vol 1541 (1) ◽  
pp. 120-126
Author(s):  
Charles J. Oswald
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Cross Sections ◽  
Soil Structure ◽  
Silty Clay ◽  
Soil Pressure ◽  
Concrete Creep ◽  
Long Span ◽  
Creep And Shrinkage ◽  
Good Agreement

Measurements made on a long span reinforced concrete arch culvert under 7.3 m (24 ft) of silty clay backfill were compared with results from finite-element analyses of the soil-structure system using the CANDE finite-element code. The culvert strains and deflections and the soil pressure on the culvert were measured during construction and during the following 2.5 years at three instrumented cross sections. The CANDE program was modified to account for the effects of concrete creep and shrinkage strains after it was noted that the measured postconstruction culvert deflection and strains increased significantly whereas the measured soil pressure on the culvert remained relatively constant. Good agreement was generally obtained between measured and calculated values of the culvert strain and deflection and the soil pressure during the entire monitoring period after the code was modified.

scholarly journals Joining of SiO2 glass and 316L stainless steel using Bi–Ag-based active solders

2020 ◽  
Vol 56 (4) ◽  
pp. 3444-3454
Author(s):  
Felix Weber ◽  
Markus Rettenmayr
Keyword(s):  
Stainless Steel ◽  
Cross Sections ◽  
316L Stainless Steel ◽  
Dissimilar Materials ◽  
Intermetallic Phases ◽  
Reaction Products ◽  
Cast State ◽  
Metallic Component ◽  
X Ray ◽  
Solder Interface

Abstract Active brazing is a commonly used method for joining dissimilar materials with at least one non-metallic component. In the present study, joining of SiO2 glass to 316L stainless steel was performed utilizing Bi–Ag-based solders. Ti up to a concentration of 4 and Mg up to 1 wt.% were added as active elements. Microstructures of the solder alloys in the as-cast state and of cross sections of the joined compounds were analysed using scanning electron microscopy and energy-dispersive X-ray spectroscopy. In the as-cast state of the solder, Ti is found in Bi–Ti intermetallic phases; Mg is partially dissolved in the fcc-(Ag) phase and additionally contained in a ternary Ag-Bi-Mg phase. After soldering, a tight joint was generated using several alloy compositions. Ti leads to the formation of reaction products at the steel/solder and glass/solder interfaces, and Mg is exclusively accumulated at the glass/solder interface.

Sign in / Sign up

Export Citation Format

Share Document