Multiple ionization of the rare gases by successive electron impacts (0–250 eV). II. 1S–2S transition in 3He+

1968 ◽  
Vol 46 (7) ◽  
pp. 865-869 ◽  
Author(s):  
P. A. Redhead ◽  
S. Feser
Keyword(s):  
Electron Energy ◽  
Cross Section ◽  
Mass Spectrometer ◽  
Ion Current ◽  
Rare Gases ◽  
Close Coupling ◽  
Trapped Ion ◽  
Multiple Ionization ◽  
Electron Impacts ◽  
Autoionizing States

The tertiary collision sequence of electrons with helium (He → He+ → He+m(2S) → He2+) has been observed with a trapped-ion mass spectrometer. The variation of He2+ ion current with electron energy shows a threshold at 40.8 eV, and structure, which results from excitation to autoionizing states of the atom below the n = 3 threshold of He+, is observed in the range 45–49 eV. Estimates of the cross section for the 1S–2S transition in He+ lie slightly below the values from close-coupling calculations.

Cross Section Ratios for the Electron Impact Production of Singly and Multiply Ionized Rare Gas Ions

1978 ◽  
Vol 33 (9) ◽  
pp. 1111-1113 ◽  
Author(s):  
F. Egger ◽  
T. D. Mark
Keyword(s):  
Electron Impact ◽  
Cross Section ◽  
Mass Spectrometer ◽  
Cross Sections ◽  
Impact Ionization ◽  
Rare Gas ◽  
Ionization Cross ◽  
Single Ionization ◽  
Multiple Ionization ◽  
Ionization Cross Sections

Electron impact ionization of He, Ne, Ar, Kr and Xe has been studied with a double focussing mass spectrometer Varian MAT CH5. Ratios of various multiple ionization cross sections with respect to single ionization cross sections for He, Ne, Ar, Kr and Xe at electron energies of 50, 100 and 150eV are given. These cross section ratios are com­pared with previous determinations.

MULTIPLE IONIZATION OF THE RARE GASES BY SUCCESSIVE ELECTRON IMPACTS (0–250 eV): I. APPEARANCE POTENTIALS AND METASTABLE ION FORMATION

1967 ◽  
Vol 45 (5) ◽  
pp. 1791-1812 ◽  
Author(s):  
P. A. Redhead
Keyword(s):  
Electron Emission ◽  
Ion Source ◽  
Metastable States ◽  
Rare Gases ◽  
Trapped Ion ◽  
Sharp Maximum ◽  
Multiple Ionization ◽  
Metastable Ions ◽  
Charge Multiplicity ◽  
Charged Ions

Multiple ionization of the rare gases has been examined in a mass spectrometer with a trapped-ion source. Ions with charge multiplicity up to n = 2 (He), n = 5 (Ne), n = 6 (Ar), n = 7 (Kr), and n = 10 (Xe) were observed with electron energies less than 250 eV. For He and Ne the thresholds agree with spectroscopic values of the ionization potentials, indicating a process of the form eN/ee(N + 1), where N represents an ion of charge multiplicity n. For Ar, Kr, and Xe, processes involving metastable states of the ion are also observed, eN/eNm; eNm/ee(N + 1). The estimated energies of the metastable levels of Ar+, Kr+, Xe+, Ar2+, and Xe2+ are in agreement with spectroscopic values. The energies of the metastable states of Ar+, Kr+, and Xe+ are in agreement with measurements of Auger electron emission from metals by metastable ions. The metastable levels estimated for the more highly charged ions (up to n = 5 for Ar, n = 6 for Kr, and n = 8 for Xe) have not been observed previously. The excitation functions of the metastable levels of Ar+, Kr+, and Xe+ are very similar and show a very sharp maximum near threshold.

A Poor Man’s Approach to Semi-Quantitative Analysis with Electron Energy Loss Spectroscopy

1980 ◽  
Vol 38 ◽  
pp. 110-111
Author(s):  
M. Isaacson
Keyword(s):  
Quantitative Analysis ◽  
Energy Loss ◽  
Electron Energy ◽  
Cross Section ◽  
Electron Energy Loss Spectroscopy ◽  
Excitation Cross Section ◽  
Incident Electron ◽  
Integral Cross Section ◽  
Image Position ◽  
Electron Energy Loss

In an earlier paper1 it was found that to a good approximation, the efficiency of collection of electrons that had lost energy due to an inner shell excitation could be written as where σE was the total excitation cross-section and σE(θ, Δ) was the integral cross-section for scattering within an angle θ and with an energy loss up to an energy Δ from the excitation edge, EE. We then obtained: where , with P being the momentum of the incident electron of velocity v. The parameter r was due to the assumption that d2σ/dEdΩ∞E−r for energy loss E. In reference 1 it was assumed that r was a constant.

scholarly journals Online Parallel Accumulation–Serial Fragmentation (PASEF) with a Novel Trapped Ion Mobility Mass Spectrometer

2018 ◽  
Vol 17 (12) ◽  
pp. 2534-2545 ◽  
Author(s):  
Florian Meier ◽  
Andreas-David Brunner ◽  
Scarlet Koch ◽  
Heiner Koch ◽  
Markus Lubeck ◽  
...  
Keyword(s):  
Mass Spectrometer ◽  
Ion Mobility ◽  
Trapped Ion

A measurement of the ionization cross-section of Ne + to Ne 2+ by electron impact

1963 ◽  
Vol 274 (1359) ◽  
pp. 546-551 ◽  
Keyword(s):  
Electron Energy ◽  
Cross Section ◽  
Ionization Cross Section ◽  
Incident Electron Energy ◽  
Ionization Cross ◽  
Maximum Value ◽  
Beam Method ◽  
The Cross ◽  
Semi Empirical ◽  
Limits Of Error

The crossed-beam method described by the authors in 1961 was used to measure the cross-section of Ne + in the reaction Ne + + e → Ne 2+ + 2 e . The cross-section increases linearly with electron energy near the threshold and attains a maximum value of 3·13 x 10 -17 cm 2 at 200 eV. The errors in the measurements were estimated to be less than ± 10% and the highest incident electron energy used was 1000 eV. A semi-empirical formula proposed by Drawin in 1961 describes the measured cross-section within the above limits of error when the two adjustable parameters take the values ξf 1 = 5·25 and f 2 = 0·70.

THERMAL NEUTRON ABSORPTION CROSS SECTION OF Xe135

1959 ◽  
Vol 37 (5) ◽  
pp. 531-536 ◽  
Author(s):  
H. R. Fickel ◽  
R. H. Tomlinson
Keyword(s):  
Thermal Neutron ◽  
Cross Section ◽  
Mass Spectrometer ◽  
Absorption Cross Section ◽  
Yield Ratio ◽  
Neutron Absorption ◽  
Absorption Cross ◽  
Fission Yield ◽  
Effective Neutron ◽  
Neutron Absorption Cross Section

The effective neutron absorption cross section of Xe135 has been measured with a mass spectrometer by observing the variation in the Cs135/Cs137 fission yield ratio obtained at various thermal neutron fluxes. Values of 3.15 ± 0.06 megabarns and 3.27 ± 0.11 megabarns have been determined for neutron temperatures of 120 °C and 137 °C respectively.

Mass and Collision Cross-Section Determination Using a Low-Vacuum Mass Spectrometer

1999 ◽  
Vol 71 (3) ◽  
pp. 648-651 ◽  
Author(s):  
Sven Ring ◽  
Ron Naaman ◽  
Yinon Rudich
Keyword(s):  
Cross Section ◽  
Mass Spectrometer ◽  
Collision Cross Section
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