K-, L-, and M-shell ionization of atoms by electron and positron impact

1996 ◽  
Vol 74 (7-8) ◽  
pp. 376-383 ◽  
Author(s):  
S. P. Khare ◽  
J. M. Wadehra
Keyword(s):  
Experimental Data ◽  
Cross Sections ◽  
Positron Impact ◽  
Electrons And Positrons ◽  
Virtual Photons ◽  
Plane Wave Born Approximation ◽  
Ionization Cross Sections ◽  
Impact Energies ◽  
Shell Ionization ◽  
Good Agreement

The plane-wave Born approximation with Coulomb, relativistic, and exchange corrections is employed to obtain the K-, L1-, L2-, L3-, and M-shell ionization cross sections of a number of atoms bombarded by electrons and positrons in the energy range varying from the threshold of ionization to 1 GeV. Transverse interaction of virtual photons with atoms is also included and it is found to be of great significance for impact energies greater than about 1 MeV. For K- and L-shell ionization, good agreement between the theoretical values and various experimental data for electron-impact cross sections is obtained. However, for the M shell, the theory overestimates the experimental cross sections. For positron impact the agreement between the present results and the limited experimental data is found to be quite satisfactory.

ENERGY-LOSS EFFECT IN K-SHELL IONIZATION

1998 ◽  
Vol 08 (04) ◽  
pp. 225-233 ◽  
Author(s):  
TAKESHI MUKOYAMA
Keyword(s):  
Energy Loss ◽  
Cross Sections ◽  
Relativistic Correction ◽  
Correction Method ◽  
Exact Integration ◽  
Plane Wave Born Approximation ◽  
Ionization Cross Sections ◽  
Energy And Momentum ◽  
Shell Ionization ◽  
Loss Effect

The energy-loss effect of the projectile for direct inner-shell ionization cross sections by charged-particle impact has been examined. The relativistic and nonrelativistic calculations for K-shell ionization with and without the energy-loss effect are made in the plane-wave Born approximation and compared with the Brandt-Lapicki theory for the corrections of the relativistic and energy-loss effect. It is demonstrated that the Brandt-Lapicki method gives a good approximation to both relativistic and nonrelativistic cross sections, which implicitly take into account the energy-loss effect. However, the use of the Brandt-Lapicki relativistic correction method in the nonrelativistic theory with the exact integration limits for energy and momentum transfer overestimates the relativistic calculations for low-energy projectiles. This indicates that the Brandt-Lapicki method for correction of the electronic relativistic effect should be used only with their energy-loss correction method.

Preliminary Measurement of the K-Shell Ionization Cross Sections of Ti by Positron Impact in the Low Energy Region

2012 ◽  
Vol 14 (5) ◽  
pp. 434-437 ◽  
Author(s):  
Lixia Tian ◽  
Mantian Liu ◽  
Jingjun Zhu ◽  
Zhu An ◽  
Baoyi Wang ◽  
...  
Keyword(s):  
Cross Sections ◽  
Energy Region ◽  
Low Energy ◽  
Positron Impact ◽  
Ionization Cross ◽  
Preliminary Measurement ◽  
Ionization Cross Sections ◽  
Shell Ionization

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.

K-shell ionization cross sections of K and Lα X-ray production cross sections of I by 10–30 keV electron impact

2012 ◽  
Vol 90 (2) ◽  
pp. 125-130 ◽  
Author(s):  
Y. Wu ◽  
Z. An ◽  
Y.M. Duan ◽  
M.T. Liu ◽  
X.P. Ouyang
Keyword(s):  
Experimental Data ◽  
Electron Impact ◽  
Cross Sections ◽  
Production Cross ◽  
Carbon Substrate ◽  
Ionization Cross ◽  
X Ray ◽  
Pure Carbon ◽  
Ionization Cross Sections ◽  
Shell Ionization

The absolute K-shell ionization cross sections of K and Lα X-ray production cross sections of I by 10–30 keV electron impact have been measured. The target was prepared by evaporating a thin film of compound KI to a thick pure carbon substrate. The effects of multiple scattering of electrons penetrating the target films, electrons reflected from the thick pure carbon substrates and bremsstrahlung photons produced when incident electrons impacted on the targets were corrected by using the Monte Carlo method. For K K-shell and I L-shell X-ray characteristic peaks, the spectra were fitted using the spectrum-fitting program ALLFIT to extract the Kα and Kβ peak counts more accurately for element K, and Lα peak counts for element I. The experimental results were compared with some theoretical results developed recently and available experimental data from the literature. The experimental data for I L-shell X-ray production cross sections by 10–30 keV electron impact are given here for the first time.

Single ionization by positron impact

1996 ◽  
Vol 74 (7-8) ◽  
pp. 367-372 ◽  
Author(s):  
J. Moxom ◽  
P. Ashley ◽  
G. Laricchia
Keyword(s):  
Energy Range ◽  
Cross Sections ◽  
Positron Impact ◽  
Ionization Cross ◽  
Positron Scattering ◽  
Direct Ionization ◽  
Low Energies ◽  
Ionization Cross Sections ◽  
Impact Energies ◽  
Existing Data

The single direct ionization cross sections for positron scattering [Formula: see text] on He, Ar, Kr, and H2 were measured and compared with existing data and the corresponding cross sections for electron impact [Formula: see text]. At most impact energies the present data for He and H2 are in reasonable accord with other measurements and, in the case of He, with some of the available calculations. At low energies, [Formula: see text] is found to increase more slowly than [Formula: see text], probably due to the importance of Ps formation in this energy range.

Measurements of K-shell ionization cross sections of Fe, Ni, and Zn by 7–29 keV electron impact using the thick-target method

2020 ◽  
Vol 98 (10) ◽  
pp. 970-975
Author(s):  
L.X. Tian ◽  
C.C. Dai ◽  
Y.J. Liu
Keyword(s):  
Experimental Data ◽  
Electron Impact ◽  
Cross Sections ◽  
Thick Target ◽  
Tikhonov Regularization Method ◽  
Ionization Cross ◽  
Bremsstrahlung Photons ◽  
Ill Posed ◽  
Ionization Cross Sections ◽  
Shell Ionization

The measurements of K-shell ionization cross sections for Fe, Ni, and Zn were performed using 7–29 keV electron impact on thick targets. Monte Carlo simulations were employed to correct the effects due to the multiple-scattered electrons and bremsstrahlung photons as well as other secondary particles within the thick targets. The so-called Tikhonov regularization method was adopted to deal with the ill-posed inverse problem involved in the thick-target method. The experimental results were compared with the DWBA and PWBA-C-Ex predictions as well as existing experimental data from the literature. It is observed that our experimental data are in better agreement with the theoretical results based on the DWBA model developed by Bote et al.

Electron Impact Ionization Cross Sections of N2 and O2

1975 ◽  
Vol 53 (11) ◽  
pp. 1044-1046 ◽  
Author(s):  
Suresh Chandra ◽  
Udit Narain
Keyword(s):  
Experimental Data ◽  
Energy Range ◽  
Electron Impact ◽  
Cross Sections ◽  
Impact Ionization ◽  
Electron Impact Ionization ◽  
Ionization Cross ◽  
Ionization Cross Sections ◽  
Good Agreement

The ionization cross sections of N2 and O2 have been calculated in the energy range from threshold to 20 keV using a modified approach. The results are in good agreement with the available experimental data.

Measurement of K-Shell ionization cross sections of Al by 4–9 keV positron impact

2021 ◽  
Vol 180 ◽  
pp. 109321
Author(s):  
S. Liang ◽  
Y. Wu ◽  
Z. Zhao ◽  
X.G. Xia ◽  
Z.X. Ke ◽  
...  
Keyword(s):  
Cross Sections ◽  
Positron Impact ◽  
Ionization Cross ◽  
Ionization Cross Sections ◽  
Shell Ionization
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