K-X RAY PRODUCTION CROSS SECTIONS OF HEAVY LANTHANIDES OVER THE ENERGY RANGE OF 3–40 MeV/amu

1995 ◽  
Vol 05 (01) ◽  
pp. 57-67 ◽  
Author(s):  
K. SERA ◽  
K. ISHII ◽  
H. ORIHARA ◽  
S. MORITA
Keyword(s):  
Energy Range ◽  
Cross Sections ◽  
Production Cross ◽  
Ionization Cross ◽  
X Ray ◽  
Heavy Lanthanides ◽  
Wide Energy ◽  
Ion Impact ◽  
Ionization Cross Sections ◽  
Ecpssr Theory

Partial K-x ray production cross sections of dysprosium, erbium and lutetium by proton and 3He-ion impact have been measured over the incident energy range of 3-40 MeV/amu. It is found that the measured ionization cross sections become larger in comparison with the prediction of PWBA theory and agree well with the ECPSSR theory in the wide energy region. This fact means that relativistic effect of inner-shell electrons is the most predominant among many effects such as the energy loss and the Coulomb deflection of the projectile and also the effects of polarization and increased binding energy of orbital electrons in the perturbed stationary states.

L AND M X-RAY PRODUCTION CROSS SECTIONS OF HEAVY RARF EARTH ELEMENTS IN THE 3-40 MeV/amu PROJECTILE-ENERGY RANGE

1998 ◽  
Vol 08 (04) ◽  
pp. 253-266 ◽  
Author(s):  
K. SERA ◽  
K. ISHII ◽  
H. ORIHARA
Keyword(s):  
Energy Range ◽  
Cross Sections ◽  
Production Cross ◽  
Projectile Energy ◽  
Ionization Cross ◽  
X Ray ◽  
Ion Impact ◽  
Ionization Cross Sections ◽  
Ecpssr Theory ◽  
First Time

Partial L- and M-x-ray production cross sections for Dy , Er and Lu have been systematically measured over the wide projectile-energy range of 3-40 MeV/amu for proton and 3 He -ion impact, and values of partial x-ray production cross sections were compared with those predicted by the ECPSSR theory. As the result, it is confirmed that the ECPSSR theory gives consistent ionization cross sections for each subshell in L- and M-shells. It is also found that values of x-ray transition rate are correct for Mα,β and Lα12 lines which are predominant in M and L x-ray spectra, respectively. However, it is pointed out that some of the values of x-ray transition rates must be revised, and improved values were obtained experimentally for the first time.

LIGHT ION-INDUCED L-SHELL IONIZATION OF HIGH-Z ELEMENTS

1996 ◽  
Vol 06 (01n02) ◽  
pp. 39-50 ◽  
Author(s):  
E. PERILLO ◽  
P. CUZZOCREA ◽  
N. DE CESARE ◽  
G. SPADACCINI ◽  
M. VIGILANTE
Keyword(s):  
Cross Sections ◽  
Production Cross ◽  
Wave Functions ◽  
Ionization Cross ◽  
X Ray ◽  
Li Ion ◽  
Ion Impact ◽  
Ionization Cross Sections ◽  
Coupled Channel ◽  
Shell Ionization

L-shell X-ray production cross sections for selected heavy elements (Tl, Pb, Bi), of interest in BIO-PIXE analyses, have been measured by proton and 7 Li ion impact in the energy range 0.8–2.6 MeV and 1.8–3.3 MeV respectively. Further, production cross sections for 7 Li ion impact on Au between 1.0 and 2.4 MeV have been measured. L-subshell ionization cross sections have been extracted and arranged, together with similar results from other laboratories, in an analysis aiming at testing the performance of various theoretical approximations in the description of the ionization process. The disagreement observed at low values of the reduced velocity parameter ξ R L between the data and the predictions of the ECPSSR model is significantly reduced by using a United Atom approximation in the treatment of the binding correction, suggested by our group (ECPSSR-UA). The remaining discrepancies, mostly for the L 1-subshell, are almost completely removed by replacing the screened hydrogenlike wave functions with the more realistic Dirac-Hartree-Slater ones. In the case of 7 Li ions, especially for L 2-subshell, also a more refined Coulomb deflection correction and more sophisticated coupled channel calculations are needed.

MATRIX EFFECTS ON K-SHELL IONIZATION CROSS SECTIONS IN Al/Si ALLOYS

2002 ◽  
Vol 12 (01n02) ◽  
pp. 1-5
Author(s):  
M. NEKAB ◽  
Ch. HEITZ
Keyword(s):  
Cross Sections ◽  
Matrix Effects ◽  
Production Cross ◽  
Heavy Ion ◽  
Double Scattering ◽  
Scattering Mechanism ◽  
Ionization Cross ◽  
X Ray ◽  
Ionization Cross Sections ◽  
Shell Ionization

Thick targets consisting in Al/Si alloys were bombarded with 1.0 to 5.0 MeV Ar ions. The K X-ray production cross sections were deduced from the measured yields by using the Merzbacher-Lewis formula extended to heavy ion bombardment. The density dependence on the K X-ray production cross sections of Al and Si was observed. This phenomena can be interpreted within the molecular orbital double-scattering mechanism.

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.

INNER-SHELL IONIZATION BY LIGHT-ION IMPACT

1991 ◽  
Vol 01 (03) ◽  
pp. 209-239 ◽  
Author(s):  
TAKESHI MUKOYAMA
Keyword(s):  
Cross Sections ◽  
Relativistic Effect ◽  
Target Electron ◽  
Ionization Cross ◽  
Plane Wave Born Approximation ◽  
Inner Shell Ionization ◽  
Ion Impact ◽  
Ionization Cross Sections ◽  
Ecpssr Theory ◽  
Shell Ionization

The ECPSSR theory to calculate the inner-shell ionization cross sections by light-ion impact is studied. Starting from the general formulation of the plane-wave Born approximation, the corrections for the energy-loss effect (E) and the Coulomb-deflection effect (C) of the projectile, and for the binding-polarization effect in the perturbed-stationary-state approach (PSS) and the electronic relativistic effect (R) of the target electron are described. The calculated values in the ECPSSR theory are compared with the experimental data. In general, agreement is good, but there are systematic deviations for low-energy projectiles. The comparison with other theoretical treatments for the inner-shell ionization is discussed.

CROSS SECTIONS FOR L X-RAY PRODUCTION IN Ba, La AND Ce BY 1 TO 3.5 MeV PROTONS

1990 ◽  
Vol 01 (01) ◽  
pp. 63-72 ◽  
Author(s):  
A. KADOM-AL-NEAMI ◽  
A. AL-NEAMI ◽  
M. BORDAS ◽  
J. LARCHER ◽  
C. HEITZ
Keyword(s):  
Cross Sections ◽  
Production Cross ◽  
Ionization Cross ◽  
X Ray ◽  
Experimental Values ◽  
Ionization Cross Sections ◽  
Mev Protons

Ba, La and Ce L X-ray production cross sections by 1 to 3.5 MeV protons have been measured for thin and thick targets. The experimental values are compared to those calculated from theoretical L subshell ionization cross sections and to experimental values determined by other authors for elements 50 to 92.

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