scholarly journals Total and Differential Cross-Sections of 16O(γ,n)3Heα8Be0 Reaction

2018 ◽  
Vol 63 (1) ◽  
pp. 3
Author(s):  
S. M. Afanasiev

The 16O(g,n)3He3a-reaction was investigated with the aid of the diffusion camera placed in the magnetic field and irradiated with a beam of bremsstrahlung g-quanta with an endpoint energy of 150 MeV. In to the curve of excitation of the system of 2a‑particles the resonance, identified as the ground state of the nucleus 8Be, were observed. The partial channels of production of these state (16O(g,n)3Hea8Ве0) were isolated and kinematical parameters of g-quantum and neutron were calculated. The absolute total cross-section of the partial channels in the energy interval from the threshold up to 120 MeV was measured. It has been established that the reaction is of a successive type: at first, the neutron is knocked out, and the residual nucleus 15О is in the excited state. The differential cross sections 16O(g,n)3Hea8Ве0-reaction has been measured and the dependence of the asymmetry coefficient distributions of the g-quantum energy and the excitation energy of the compound nucleus at the first intermediate stage of decomposition. The results are explained by the quantum interaction with a quasideuterons model.

2009 ◽  
Vol 24 (02n03) ◽  
pp. 450-453
Author(s):  
◽  
T. SKORODKO ◽  
M. BASHKANOV ◽  
D. BOGOSLOWSKY ◽  
H. CALÉN ◽  
...  

The two-pion production in pp-collisions has been investigated in exclusive measurements from threshold up to Tp = 1.36 GeV . Total and differential cross sections have been obtained for the channels pnπ+π0, ppπ+π-, ppπ0π0 and also nnπ+π+. For intermediate incident energies Tp > 1 GeV , i.e. in the region, which is beyond the Roper excitation but at the onset of ΔΔ excitation the total ppπ0π0 cross section falls behind theoretical predictions by as much as an order of magnitude near 1.2 GeV, whereas the nnπ+π+ cross section is a factor of five larger than predicted. A model-unconstrained isospin decompostion of the cross section points to a significant contribution of an isospin 3/2 resonance other than the Δ(1232). As a possible candidate the Δ(1600) is discussed.


2019 ◽  
Vol 24 ◽  
pp. 36
Author(s):  
M. Axiotis ◽  
A. Lagoyannis ◽  
S. Fazinić ◽  
S. Harrisopulos ◽  
M. Kokkoris ◽  
...  

The application of standard-less PIGE requires the a priori knowledge of the differential cross section of the reaction used for the quantification of each detected light element. Towards this end, a lot of datasets have been published the last few years from several laboratories around the world. The discrepancies found can be resolved by applying a rigorous benchmarking procedure through the measurement of thick target yields. Such a procedure is proposed in the present paper and is applied in the case of the 19F(p,p’γ)19F reaction.


2012 ◽  
Vol 9 (3) ◽  
pp. 554-558 ◽  
Author(s):  
Baghdad Science Journal

The differential cross section for the Rhodium and Tantalum has been calculated by using the Cross Section Calculations (CSC) in range of energy(1keV-1MeV) . This calculations based on the programming of the Klein-Nashina and Rayleigh Equations. Atomic form factors as well as the coherent functions in Fortran90 language Machine proved very fast an accurate results and the possibility of application of such model to obtain the total coefficient for any elements or compounds.


2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
M. Aaboud ◽  
◽  
G. Aad ◽  
B. Abbott ◽  
O. Abdinov ◽  
...  

Two additions impacting tables 3 and 4 in ref. [1] are presented in the following. No significant impact is found for other results or figures in ref. [1].


Differential cross-sections have been measured for the scattering of photons of mean energy 87 MeV by uranium at eight angles in the range from 1.18 to 4.48 mrad and by aluminium, silver, tungsten, lead and uranium at angles of 1.89 and 4.24 mrad, using a narrowly collimated bremsstrahlung beam from the Oxford 110 MeV synchrotron as the primary source of photons. A biased total-absorption Čerenkov counter was used to detect photons with energies near the peak energy of the bremsstrahlung spectrum, and absolute differential cross-sections were measured by comparing counting rates for photons in the primary and scattered beams. The experimental results, with the differential Compton scattering cross-sections of Klein and Nishina subtracted, were analyzed in terms of their variation with angle and atomic number, and can be described as consisting of a sharply peaked angular distribution with absolute cross-sections varying from element to element as Z 4 , together with a uniform distribution varying nearly as Z 2 ; these distributions were identified with Delbruck scattering and with bremsstrahlung from secondary electrons in the scattering target, respectively. The Delbruck scattering cross-section thus determined is slightly more sharply peaked than the cross-section predicted by an approximate theory of Bethe & Rohrlich.


1990 ◽  
Vol 10 (5-6) ◽  
pp. 319-332 ◽  
Author(s):  
N. Billy ◽  
B. Girard ◽  
G. Gouédard ◽  
J. Vigué

Differential cross sections can be measured as a function of the internal state of a reaction product thanks to the analysis of the Doppler profile of the laser induced fluorescence detection line. This analysis is complicated by two effects: first, the LIF signal intensity depends on the interaction time of the molecule with the laser, and this time depends on the scattering angle, second, the angular and velocity distributions of the beams have non negligible widths. We present here a treatment of these effects in the case of the F+I2 reaction for which we have measured the differential cross section by this technique. The same formalism is also applied to the deduction of the rovibrational distribution of the products from the relative intensities of the LIF lines.


1973 ◽  
Vol 51 (20) ◽  
pp. 2197-2201 ◽  
Author(s):  
P. W. Martin ◽  
R. McFadden ◽  
B. L. White

The differential cross sections for 4.3 MeV neutrons elastically scattered from natural samples of U, Bi, and Pb have been measured at laboratory angles of 5, 10, and 15°. In the case of uranium, the data are consistent with calculations based on the nuclear optical model and known electromagnetic interactions. Less satisfactory agreement to the data is obtained in the cross section measurements for lead and bismuth.


2012 ◽  
Vol 20 ◽  
pp. 89
Author(s):  
V. Paneta ◽  
A. Lagoyannis ◽  
A. Kafkarkou ◽  
M. Kokkoris

Differential cross sections of the 7Li(p,p0)7Li, 7Li(p,p1)7Li, 7Li(p,α0)4He, 19F(p,p0), 19F(p,α0)16O and 19F(p,α1,2)16O reactions have been determined for proton energies Elab=1500-7000 keV, using a variable energy step and for detection angles between 140-170 degrees in steps of 10 degrees. To validate the obtained results, benchmarking measurements were performed, using thick and mirror-polished BaF2 and LiF targets. The experimental data are compared to data from literature, when available, and similarities and discrepancies are presented and analyzed.


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