Some experimental results on the measurement of the total photoabsorption cross sections

2008 ◽  
pp. 216-257 ◽  
Author(s):  
G.V. Solodukhov
Keyword(s):  
Cross Sections ◽  
Experimental Results

scholarly journals Experimental study of the $ \gamma p \rightarrow K^{0}\Sigma^{+}$, $ \gamma n \rightarrow K^{0} \Lambda$, and $ \gamma n \rightarrow K^{0} \Sigma^{0}$ reactions at the Mainz Microtron

2019 ◽  
Vol 55 (11) ◽  
Author(s):  
C. S. Akondi ◽  
K. Bantawa ◽  
D. M. Manley ◽  
S. Abt ◽  
P. Achenbach ◽  
...  
Keyword(s):  
Experimental Study ◽  
Cross Sections ◽  
Differential Cross ◽  
Legendre Polynomials ◽  
Neutral Kaon ◽  
Experimental Results ◽  
Differential Cross Sections ◽  
Theoretical Predictions ◽  
Photoproduction Reactions ◽  
Insight Into

Abstract.This work measured $ \mathrm{d}\sigma/\mathrm{d}\Omega$dσ/dΩ for neutral kaon photoproduction reactions from threshold up to a c.m. energy of 1855MeV, focussing specifically on the $ \gamma p\rightarrow K^0\Sigma^+$γp→K0Σ+, $ \gamma n\rightarrow K^0\Lambda$γn→K0Λ, and $ \gamma n\rightarrow K^0 \Sigma^0$γn→K0Σ0 reactions. Our results for $ \gamma n\rightarrow K^0 \Sigma^0$γn→K0Σ0 are the first-ever measurements for that reaction. These data will provide insight into the properties of $ N^{\ast}$N* resonances and, in particular, will lead to an improved knowledge about those states that couple only weakly to the $ \pi N$πN channel. Integrated cross sections were extracted by fitting the differential cross sections for each reaction as a series of Legendre polynomials and our results are compared with prior experimental results and theoretical predictions.

Multiple ionization of argon by positron impact

1996 ◽  
Vol 74 (7-8) ◽  
pp. 373-375 ◽  
Author(s):  
R. Hippler ◽  
S. Helms ◽  
U. Brinkmann ◽  
J. Deiwiks ◽  
H. Schneider ◽  
...  
Keyword(s):  
Electron Impact ◽  
Cross Sections ◽  
Experimental Results ◽  
Positronium Formation ◽  
Positron Impact ◽  
Single Ionization ◽  
Multiple Ionization

Recent experimental results for the multiple ionization of argon by positron impact have been reanalysed. Absolute cross sections for the double and triple ionization of argon were obtained from measured ratios of double-to-single and triple-to-single ionization, using known cross sections for single ionization and for positronium formation. Distinct differences compared to similar results for electron impact are noted.

L X-ray fluorescence cross sections in the atomic region 59 ≤ Z ≤ 82 excited by 16.58 keV photons

1996 ◽  
Vol 74 (5-6) ◽  
pp. 230-235 ◽  
Author(s):  
D. V. Rao ◽  
R. Cesareo ◽  
G. E. Gigante
Keyword(s):  
Excitation Energy ◽  
Least Squares ◽  
Cross Sections ◽  
Experimental Results ◽  
X Ray ◽  
Experimental Cross ◽  
Average Fluorescence ◽  
Good Agreement

LL, Lα, Lβ, and Lγ X-ray fluorescence cross sections for Pr, Sm, Gd, Dy, Ho, Er, Yb, Pt Au, and Pb were measured at the excitation energy 16.58 keV. An X-ray tube and a secondary excitor system was used instead of radioisotopes for the measurements. Experimental cross sections are compared with the theoretical estimates based on relativistic Dirac–Hartree–Slater theory. Average L-shell fluorescence yields [Formula: see text] are deduced using the present experimental cross sections and the theoretical subshell photoionization cross sections. The derived average fluorescence yields are fitted by least squares to polynomials in Z of the form ΣnanZn and compared with theoretical and earlier fitted values. Good agreement is observed ' between the experimental results and the theoretical estimates based on relativistic Dirac–Hartree–Slater theory.

Assessment of the numerical and experimental performance of screw tidal turbines

2018 ◽  
Vol 232 (7) ◽  
pp. 912-925 ◽  
Author(s):  
Hamid Rahmani ◽  
Mojtaba Biglari ◽  
Mohammad Sadegh Valipour ◽  
Kamran Lari
Keyword(s):  
Output Power ◽  
Water Flow ◽  
Cross Sections ◽  
Turbine Blades ◽  
Transient State ◽  
Experimental Results ◽  
Ansys Fluent ◽  
Tidal Turbines ◽  
Collision Problem ◽  
Mesh Independence

This study was aimed at the numerical and experimental modeling of water flow during collision between water and vertical screw turbine blades with different cross sections (i.e. Darrieus, spoon, and airfoil). ANSYS Fluent was used to model water flow under tidal currents in a flume, and mesh independence was ensured after the selection of appropriate geometry. The collision problem was then solved in the transient state, and results on the momentum and power generated by different inlet velocities and different blade cross sections were analyzed. The findings showed that torque and turbine power increased with increasing inlet velocity. Subsequently, a turbine was experimentally created, with cross sections drawn in the numerical model and tested under the same conditions as that imposed on the model. Installing a multimeter on the turbine enabled the generation of turbine power in different dimensions. The resultant power increased with rising turbine dimensions. After obtaining the numerical and experimental results, the value of the output power of the turbine was validated. The validation indicated a 7% difference in output power between the numerical and experimental results, indicating acceptable accuracy.

scholarly journals The Electron Impact Ionization Cross Sections of Methanol, Ethanol and 1-Propanol

Atoms ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 60 ◽  
Author(s):  
Yogesh Kumar ◽  
Manoj Kumar ◽  
Sachin Kumar ◽  
Rajeev Kumar
Keyword(s):  
Electron Impact ◽  
Cross Sections ◽  
Impact Ionization ◽  
Experimental Results ◽  
Oscillator Strengths ◽  
Ionization Cross ◽  
Total Ionization ◽  
Plane Wave Born Approximation ◽  
Ionization Cross Sections ◽  
Good Agreement

In the present investigation, the plane-wave Born approximation was employed to calculate the total ionization cross sections by electron impact of methanol, ethanol and 1-propanol from the threshold of ionization to 10 MeV. This method requires continuum generalized oscillator strengths (CGOSs). The two different semi-phenomenological expressions of CGOS, given by Mayol and Salvat and Weizsacker and Williams, along with approximated form of the continuum optical oscillator strength (COOS) by Khare et al. were used. Furthermore, the average of the above two CGOSs was also used. The calculated ionization cross sections were compared to the available previous theoretical results and experimental data. Out of three CGOSs, the present results with the average CGOS were found in good agreement with the available experimental results for all the considered molecules. Collision parameters CRP were also calculated from 0.1 to 100 MeV and the calculations were found to be in excellent agreement with the experimental results of Reike and Prepejchal.

The Application of Finite Element Techniques to the Analysis of an Automobile Structure: First Paper: Static Analysis of an Automobile Chassis Frame

1970 ◽  
Vol 185 (1) ◽  
pp. 665-674 ◽  
Author(s):  
R. Ali ◽  
J. L. Hedges ◽  
B. Mills
Keyword(s):  
Finite Element ◽  
Computer Program ◽  
Static Analysis ◽  
Cross Sections ◽  
Experimental Results ◽  
Finite Element Technique ◽  
Beam Elements ◽  
Manufacturing Tolerances ◽  
Element Technique

The finite element technique has been used for the static analysis of a chassis structure. A computer program was developed to predict static deflections under bending and torsion loads. The program is quite general, but its use has been restricted to structures consisting of beam elements only. The effects of shear deflections and tapered beams and manufacturing tolerances of cross sections are also considered. Predictions of static deflections are compared with experimental results.

scholarly journals Do we understand near-forward elastic scattering up to TeV energies?

2015 ◽  
Vol 30 (08) ◽  
pp. 1542006 ◽  
Author(s):  
Claude Bourrely ◽  
Jacques Soffer ◽  
Tai Tsun Wu
Keyword(s):  
Experimental Data ◽  
Elastic Scattering ◽  
Cross Sections ◽  
Phenomenological Model ◽  
Experimental Results ◽  
Proton Proton ◽  
Total Cross Sections

In 1970, on purely theoretical grounds, all total hadronic total cross-sections were predicted to increase without limit for higher and higher energies. This was contrary to the conventional belief at that time. In 1978, an accurate phenomenological model was formulated for the case of proton–proton and antiproton-proton interactions. The parameters for this model were slightly improved in 1984 using the additional available experimental data. Since then, for 30 years these parameters have not changed. This development, including especially the difficult task of formulating this phenomenological model and the comparison of the predictions of this model with later experimental results, is summarized.

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