Parcourir Sciences Et Techniques par auteur "Defrance, P."
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Absolute cross sections and kinetic energy release distributions for electron-impact dissociative excitation and ionization of NeD+
2008, HENALLUXArticle scientifiqueAbsolute cross sections for electron impact dissociative excitation and ionization of NeD+ leading to the formation of singly and multiply charged products (D+, Ne+, Ne2+ and Ne3+) are reported, in the energy range from their respective thresholds to 2.5 keV. The animated crossed-beams method is used. For singly charged fragments, absolute cross sections are obtained separately for dissociative ... -
Absolute cross sections and kinetic energy release distributions for electron-impact ionization and dissociation of CD+ 4
2008, HENALLUXArticle scientifiqueAbsolute cross sections for electron-impact dissociative excitation and ionization of CD+ 4 leading to formation of ionic products (CD2+ 4, CD+ 3, CD+ 2, CD+, C+, D+ 3, D+ 2, and D+) have been measured. The animated crossed-beams method is applied in the energy range from the reaction threshold up to 2.5 keV. Around 100 eV, the maximum cross sections are found to be (3.8±0.2) ×10-19 cm2, (10.8±1.5)× ... -
Absolute cross sections and kinetic energy release for doubly and triply charged fragments produced by electron impact on CO+
2006, HENALLUXArticle scientifiqueAbsolute cross sections for electron impact ionization of CO+ leading to the formation of doubly and triply charged products (CO2+, C2+ and O2+, C3+ and O3+) are reported in the energy range from their respective thresholds to 2500 eV. Around the maximum, cross section values are found to be (13.36 ± 0.56) × 10−18 cm2, (5.58 ± 0.55) × 10−18 cm2 and (1.37 ± 0.14) × 10−18 cm2 for CO2+, C2+ and O2+, ... -
Absolute cross-sections and kinetic energy release distributions for electron-impact dissociation of D3+
2009, HENALLUXArticle scientifiqueAbsolute cross-sections for electron-impact dissociation of D+3 leading to the formation of D+ and D+2 products have been measured by applying the animated electron-ion beam method in the energy range from the respective thresholds up to 2.5 keV. The maximum total cross-sections are observed to be (13.9 ± 1.1) × 10−17 cm2 and (8.2 ± 0.1) × 10−17 cm2 (around 50 eV) for D+ and for D+2 fragments, ... -
Absolute cross-sections and kinetic-energy-release distributions for electron-impact ionization and dissociation of CD +3
2009, HENALLUXArticle scientifiqueAbsolute cross-sections have been measured for electron-impact dissociative excitation and ionization of CD+3/(CH+3) leading to formation of singly-charged fragments (CD +2, CH+, C+, H +2 and D+). The animated crossed-beams method is applied in the energy range from the reaction threshold up to 2.5 keV. The maximum cross-sections are found to be (14.0±1.0)×10-17 cm2, (6.5± 0.7)×10-17 cm2, (3.3± ... -
Absolute cross-sections and kinetic-energy-release distributions for electron-impact ionization and dissociation of CD+ 2
2009, HENALLUXArticle scientifiqueAbsolute cross-sections have been measured for electron-impact dissociative excitation and ionization of CD +2 leading to formation of CD 2+2, CD+, C+, D +2 and D+. The animated crossed-beams method is applied in the energy range from the reaction threshold up to 2.5 keV. The maximum total cross-sections are found to be (1.2±0.1)×10-17 cm2, (6.1±0.7)×10-17 cm2, (6.4±0.7)×10-17 cm2, (26.3±3.8)×10-19 ... -
A crossed-beam experiment for electron impact ionization and dissociation of molecular ions: its application to CO+
2006, HENALLUXArticle scientifiqueA crossed electron–ion beam experimental set-up has been upgraded for the study of electron impact ionization and dissociation of molecular ions by means of ionic product detection. Both the experimental set-up and the data analysis procedures are described in detail for the estimation of (i) absolute cross sections, (ii) kinetic energy release distributions (KERD) and (iii) anisotropies of angular ... -
Dissociative excitation of NeD+
2009, HENALLUXArticle scientifiqueMeasurements of NeD+ dissociative excitation cross section were obtained in Louvain-la-Neuve (UCL, Belgium) by using the animated crossed electron-ion beam method. The electronic structure of the system was calculated by using quantum chemistry calculations for the NeD+ ion and ab initio electron scattering calculations using the complex Kohn variational method for the resonant NeD neutral complex ... -
Electron impact dissociation of ND+: formation of D+
2011, HENALLUXArticle scientifiqueAbsolute cross sections for electron impact dissociation of ND+ leading to the formation of D+ have been measured by applying the animated electron-ion beam method in the energy range from the reaction threshold up to 2.5 keV. The maximum inclusive cross section is observed to be (16.8 ± 0.8) × 10−17 cm2 at the electron energy of 65.1 eV. The appearance energy for the D+ production is measured to ... -
Electron impact multiple ionization of argon ions
2010, HENALLUXArticle scientifiqueAbsolute cross sections for electron impact single and multiple ionization of argon ions leading to the formation of Ar q + (q = 2–8) are reported. The animated crossed beam method is applied in the energy range extending from the respective thresholds up to 2.5 keV. The maximum cross sections for the multiply charged products Ar q + (q = 2–8) are measured to be (12.6 ± 0.6) × 10−17 cm2 for Ar2+, ... -
Electron impact multiple ionization of C+ and N+ and O+ ions
2014, HENALLUXArticle scientifiqueAbsolute cross sections for electron impact single and multiple ionization of C+, N+ and O+ ions leading to the formation of Cq+ (q=2-4), Nq+ (q=2-5) and Oq+ (q=2-5) are reported in the energy range extending from the respective thresholds up to 2.5 keV. The general feature of the measured cross sections is investigated. -
Electron-impact dissociation and ionization of NH+: formation of N+ and N2+
2010, HENALLUXArticle scientifiqueAbsolute cross sections for electron-impact dissociation and ionization of NH+ leading to the formation of N+ and N2+ products have been measured by applying the animated electron–ion beam method, in the energy range from the respective thresholds up to 2.5 keV. The maximum total cross sections are observed to be (15.7 ± 0.7) × 10−17 cm2 and (11.1 ± 0.2) × 10−18 cm2 for N+ and N2+, respectively. ... -
Electron-impact dissociation and ionization of OH+ and OD+ ions
2012, HENALLUXArticle scientifiqueAbsolute cross sections for electron impact ionization and dissociation of OH+ and OD+ leading to the formation of the OH2+, O+, O2+, O3+ and D+ ions have been measured by applying the animated electron-ion beam method in the energy range from the respective reaction thresholds up to 2.5 keV. The maximum of the single ionization cross section is found to be (0.95±0.02) × 10−19 cm2 at 155 eV. ... -
Electron-impact dissociation of HeH+: absolute cross sections for the production of Heq+ (q = 1–2) fragments
2014, HENALLUXArticle scientifiqueAbsolute cross sections have been measured for electron-impact dissociative excitation and ionization of the helium-hydride ion (HeH+) leading to the formation of helium ions Heq+ (q = 1–2). Measurements have been performed for electron energies ranging from the respective thresholds up to 2.5 keV. For He+ production, the maximum absolute cross section for dissociative excitation is found to be (2.5 ... -
Electron-impact dissociative ionization of the molecular ion HDO + : A global view
2014, HENALLUXArticle scientifiqueWe present a combined experimental and theoretical study of the fragmentation of HDO2+ molecular ions produced by electron-impact ionization of HDO+ in the collision energy range 20–2500 eV. Experimental absolute partial inclusive cross sections for the production of OD+, OH+, and O+ are reported and compared successfully to theoretical predictions. Ab initio methods are used to calculate the ... -
Electron-impact ionization and dissociation of C2D+
2010, HENALLUXArticle scientifiqueAbsolute cross sections for electron-impact single ionization, dissociative excitation and dissociative ionization of the ethynyl radical ion (C2D+) have been measured for electron energies ranging from the corresponding reaction thresholds to 2.5 keV. The animated crossed electron-ion beam experiment is used and results have been obtained for the production of C2D2+, C2+, C+2, CD+, C+ and D+. The ... -
Electron-impact ionization of atomic hydrogen: dynamical variational treatment
2011, HENALLUXArticle scientifiqueA simple and straightforward calculating scheme is proposed for electron-impact single and multiple ionization of atoms. The method is based on the application of the Hulthén-Kohn dynamical variational principle. An effective charge seen by the scattered electron is determined for a certain type of trial wave functions mathematically in a rigorous way excluding any empirical assumptions. Validity ... -
Electron-impact ionization of singly-charged neon ions
2008, HENALLUXArticle scientifiqueAbsolute cross sections for electron-impact single and multiple ionization of Ne+ leading to the formation of Neq+ (q = 2–5) are reported. The animated crossed beams method is applied in the energy range from the respective thresholds up to 2.5 keV. The maximum cross sections are found to be (4.12 ± 0.21) × 10−17 cm2, (1.42 ± 0.07) × 1018 cm2, (2.57 ± 0.14) × 10−20 cm2, (8.78 ± 0.54) × 10−22 cm2 for ... -
I. Electron-impact ionization and dissociation of C2H +2 and C2D +2
2010, HENALLUXArticle scientifiqueAbsolute cross-sections for electron-impact ionization and dissociation of C2H +2 and C2D +2 have been measured for electron energies ranging from the corresponding thresholds up to 2.5 keV. The animated crossed beams experiment has been used. Light as well as heavy fragment ions that are produced from the ionization and the dissociation of the target have been detected for the first time. The maximum ... -
II. Electron-impact dissociative excitation of C2H +2 and C2D +2
2010, HENALLUXArticle scientifiqueAbsolute cross-sections for electron-impact dissociative excitation of C2H +2 and C2D +2 to C2D+, CH+, C+, C +2, H+ and CH +2 singly-charged fragments have been estimated. The animated crossed-beams method is applied in the energy range from the corresponding reaction threshold up to 2.5 keV. Individual contributions for dissociative excitation are determined from the analysis of the total absolute ...