scholarly journals ENERGY LOSS IN CONDENSED MATTER OF H1 AND He4 IN THE ENERGY RANGE 4 < E < 30 kev

1962 ◽  
Vol 40 (12) ◽  
pp. 1749-1764 ◽  
Author(s):  
Arie Van Wijngaarden ◽  
Henry E. Duckworth

Measurements are reported of the energy loss suffered by H1 and He4 particles, of 4- to 30-kev energy, in passing through thin films of carbon, aluminum oxide, and VYNS. Only those particles that emerged in the forward direction were studied. Evidence is presented for identifying the stopping cross sections per atom observed in this way with Se, the electronic component of the total stopping cross section per atom. It appears that the calculated energy dependence of [Formula: see text] is somewhat in error, and that the magnitudes of the Se's for He4 are systematically too small by 10–15%.

2016 ◽  
Vol 31 (33) ◽  
pp. 1630038
Author(s):  
E. P. Solodov ◽  
A. N. Amirkhanov ◽  
A. V. Anisenkov ◽  
V. M. Aulchenko ◽  
V. S. Banzarov ◽  
...  

The CMD-3 detector has been taking data since December 2010 at the VEPP-2000 electron–positron collider. The collected data sample corresponds to about 60 inverse picobarn of integrated luminosity in the c.m. energy range from 0.32 GeV to 2.0 GeV. Preliminary results of the analysis of various hadronic cross-sections, in particular, [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], 3[Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] are presented. The processes with multi-hadron final states have several intermediate states which have to be taken into account to correctly describe the angular and invariant mass distributions, as well as cross-section energy dependence.


1968 ◽  
Vol 46 (6) ◽  
pp. 497-502 ◽  
Author(s):  
J. H. Ormrod

The rate of energy loss in nitrogen and argon targets for ions with [Formula: see text] and E < 200 keV has been measured. The contribution to the energy loss from nuclear stopping was calculated using Fastrup's method, and was subtracted from the observed stopping cross section to give the electronic stopping cross section. Over the energy interval studied, the electronic stopping cross sections obtained are below the theoretical values and the energy dependence in argon is much greater than [Formula: see text].A target gas pressure of ~10 μ was used. This reduces the collision frequency eight orders of magnitude below that in a solid. The periodic dependence of the electronic stopping cross section on the atomic number of the incident projectile, previously observed in solid targets, occurs also for such low-pressure gas targets; it is concluded that this dependence is not affected by the collision frequency.


1993 ◽  
Vol 11 (3) ◽  
pp. 485-490 ◽  
Author(s):  
V.A. Rykov ◽  
P.P. Dyachenko ◽  
F.V. Mahrov ◽  
Yu.V. Sokolov

We present the cross section for the ejection of electrons from helium and argon by 252Cf fission fragments, differential in the ejected electron energy. The electron energy ranges from 10 to 1,500 eV. The experimentally obtained cross sections are compared with calculations in the framework of Gryzinski&s theory and Gerjuoy&s theory. The results of the energy loss partitioning are presented. It is demonstrated that there is reasonable agreement between Gerjuoy&s theory and experiment.


2021 ◽  
Vol 22 (2) ◽  
pp. 647
Author(s):  
Jelena Vukalović ◽  
Jelena B. Maljković ◽  
Karoly Tökési ◽  
Branko Predojević ◽  
Bratislav P. Marinković

Electron interaction with methane molecule and accurate determination of its elastic cross-section is a demanding task for both experimental and theoretical standpoints and relevant for our better understanding of the processes in Earth’s and Solar outer planet atmospheres, the greenhouse effect or in plasma physics applications like vapor deposition, complex plasma-wall interactions and edge plasma regions of Tokamak. Methane can serve as a test molecule for advancing novel electron-molecule collision theories. We present a combined experimental and theoretical study of the elastic electron differential cross-section from methane molecule, as well as integral and momentum transfer cross-sections in the intermediate energy range (50–300 eV). The experimental setup, based on a crossed beam technique, comprising of an electron gun, a single capillary gas needle and detection system with a channeltron is used in the measurements. The absolute values for cross-sections are obtained by relative-flow method, using argon as a reference. Theoretical results are acquired using two approximations: simple sum of individual atomic cross-sections and the other with molecular effect taken into the account.


1996 ◽  
Vol 74 (7-8) ◽  
pp. 505-508 ◽  
Author(s):  
R. M. Finch ◽  
Á. Kövér ◽  
M. Charlton ◽  
G. Laricchia

Differential cross sections for elastic scattering and ionization in positron–argon collisions as a function of energy (40–150 eV) are reported at 60°. Of particular interest is the energy range 55–60 eV, where earlier measurements by the Detroit group found a drop in the elastic-scattering cross section of a factor of 2. This structure has been tentatively attributed to a cross channel-coupling effect with an open inelastic-scattering channel, most likely ionization. Our results indicate that ionization remains an important channel over the same energy range and only begins to decrease at an energy above 60 eV.


KnE Energy ◽  
2018 ◽  
Vol 3 (1) ◽  
pp. 21
Author(s):  
Yu Penionzhkevich ◽  
Yu Sobolev ◽  
V Samarin ◽  
M Naumenko

The paper presents the results of measurement of the total cross sections for reactions 4,6He + Si and 6,7,9Li + Si in the beam energy range 5−50 A⋅MeV. The enhancements of the total cross sections for reaction 6He + Si compared with reaction 4He + Si, and 9Li + Si compared with reactions 6,7Li + Si have been observed. The performed microscopic analysis of total cross sections for reactions 6He + Si and 9Li + Si based on numerical solution of the time-dependent Schrödinger equation for external neutrons of projectile nuclei 6He and 9Li yielded good agreement with experimental data.


2008 ◽  
Vol 23 (27n30) ◽  
pp. 2313-2316 ◽  
Author(s):  
◽  
H. KANDA ◽  
N. CHIGA ◽  
Y. FUJII ◽  
K. FUTATSUKAWA ◽  
...  

The total cross sections for the π+π− photoproduction on the deuteron were measured in an energy range of 0.8 to 1.1 GeV. The obtained total cross section for the quasi-free π+π− photoproduction on the deuteron was about 60 % of those on the free proton. The cross section for Δ++Δ− photoproduction was derived from the non-quasi-free π+π− photoproduction events. It was smaller than the previous data.


2008 ◽  
Vol 72 (3) ◽  
pp. 356-360
Author(s):  
K. V. Lukyanov ◽  
E. V. Zemlyanaya ◽  
V. K. Lukyanov ◽  
I. N. Kukhtina ◽  
Yu. E. Penionzhkevich ◽  
...  

2020 ◽  
Vol 21 (18) ◽  
pp. 6947
Author(s):  
Filipe Costa ◽  
Ali Traoré-Dubuis ◽  
Lidia Álvarez ◽  
Ana I. Lozano ◽  
Xueguang Ren ◽  
...  

Electron scattering cross sections for pyridine in the energy range 0–100 eV, which we previously measured or calculated, have been critically compiled and complemented here with new measurements of electron energy loss spectra and double differential ionization cross sections. Experimental techniques employed in this study include a linear transmission apparatus and a reaction microscope system. To fulfill the transport model requirements, theoretical data have been recalculated within our independent atom model with screening corrected additivity rule and interference effects (IAM-SCAR) method for energies above 10 eV. In addition, results from the R-matrix and Schwinger multichannel with pseudopotential methods, for energies below 15 eV and 20 eV, respectively, are presented here. The reliability of this complete data set has been evaluated by comparing the simulated energy distribution of electrons transmitted through pyridine, with that observed in an electron-gas transmission experiment under magnetic confinement conditions. In addition, our representation of the angular distribution of the inelastically scattered electrons is discussed on the basis of the present double differential cross section experimental results.


1984 ◽  
Vol 62 (1) ◽  
pp. 1-9 ◽  
Author(s):  
K. Becker ◽  
J. W. McConkey

We have studied the Lyman [Formula: see text] and Werner [Formula: see text] band emissions produced by 20–500-eV electrons incident on molecular deuterium, D2. Emission cross sections of (3.7 ± 0.9) × 10−17 cm2 for the B → X and (3.54 ± 0.74) × 10−17 cm2 for the C → X system have been determined at 100-eV impact energy. Cascading did not play an important role in the [Formula: see text] emission, but it was shown to affect the [Formula: see text] emission seriously, particularly for impact energies below 50 eV. We estimate the cross section for direct excitation of the [Formula: see text] state and the cascade cross section to be 2.95 × 10−17 and 0.75 × 10−17 cm2, at 100 eV respectively. The cascade cross section is 20 ± 10% of the total B → X emission cross section, and is essentially constant in the energy range 300–50 eV, but increases significantly for lower impact energies, e.g., to 40 ± 15% at 27.5 eV. The cross section for the atomic 2p → 1s Lyman α emission from D2 has also been measured and the value of 1.00 × 10−17 cm2 at 100 eV is 20% smaller than the cross section for Lyman α emission from H2.


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