|
| Titre : |
Ionization of atoms and molecules by electron and positron impact: Application to Beryllium atom and Water molecule |
| Type de document : |
document électronique |
| Auteurs : |
Imene Khiat, Auteur ; Imene Kada, Directeur de thèse |
| Editeur : |
Sétif:UFA1 |
| Année de publication : |
2026 |
| Importance : |
1 vol (96 f.) |
| Format : |
29 cm |
| Langues : |
Anglais (eng) |
| Catégories : |
Thèses & Mémoires:Physique
|
| Mots-clés : |
Ionization
Correlation
Molecule |
| Index. décimale : |
530 - Physique |
| Résumé : |
In this work, both single and double ionization of atoms and molecules were studied.
For single ionization, the M3CWZ model was employed to investigate the effects of the
charge on the ionization of the water molecule by electron and positron impact. For
double ionization, the 5DCS for atoms and 6DCS for molecules were calculated for the
beryllium atom and the oriented water molecule. The calculations were performed within
the Born approximation and using the BBK model and its approximations. This study
emphasizes the importance of accounting for electron correlation and long-range interactions
in reproducing differential cross sections and elucidating the underlying ionization
mechanisms. |
| Note de contenu : |
Sommaire
List of Figures i
List of Tables vi
General Introduction 1
Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1 Theoretical Elements 1
1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Scattering Theory and Cross Sections . . . . . . . . . . . . . . . . . . . . . 2
1.2.1 Description of the Scattering Phenomenon . . . . . . . . . . . . . . 2
1.3 Integral Form of the Schrödinger Equation Using the Green’s Function . . 3
1.3.1 Scattering Amplitude . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.4 Born Approximation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.4.1 Calculation of the First Born Term . . . . . . . . . . . . . . . . . . 10
1.4.2 Calculation of the Second Born Term . . . . . . . . . . . . . . . . 11
1.5 Partial Wave Solution of the Schrödinger Equation . . . . . . . . . . . . . 12
1.6 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2 Single and Double Ionization Processes 15
2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.2 Electron Correlations in Atomic and Molecular Systems . . . . . . . . . . . 16
2.3 Wave–function Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.3.1 Atomic and MoleculariOrbitals . . . . . . . . . . . . . . . . . . . . 18
2.3.2 The Hartree Fock (HF) method . . . . . . . . . . . . . . . . . . . . 20
2.3.3 Configuration Interaction (CI) Method . . . . . . . . . . . . . . . . 21
2.3.4 Frozen Core Approximation . . . . . . . . . . . . . . . . . . . . . . 22
2.4 The Process of Single Ionization . . . . . . . . . . . . . . . . . . . . . . . . 23
2.4.1 Description of the (e,2e) Process . . . . . . . . . . . . . . . . . . . 23
2.4.2 Structural and Dynamical Studies . . . . . . . . . . . . . . . . . . . 24
2.4.3 Geometries and Kinematics of the (e,2e) process . . . . . . . . . . . 26
2.4.4 Differential Cross Sections for (e,2e) process . . . . . . . . . . . . . 28
2.5 The Process of Double Ionization . . . . . . . . . . . . . . . . . . . . . . . 30
2.5.1 Description of the (e,3e) process . . . . . . . . . . . . . . . . . . . . 30
2.5.2 Geometries and kinematics of the (e; 3e) process . . . . . . . . . . . 32
2.5.3 Differential Cross Section for (e,3e) process . . . . . . . . . . . . . . 32
2.5.4 The Mechanisms of Double Ionization . . . . . . . . . . . . . . . . . 34
2.6 Theoretical models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
2.6.1 Brauner, Briggs, and Klar (BBK) model . . . . . . . . . . . . . . . 38
2.6.2 Distorted Wave Born Approximation (DWBA) model . . . . . . . 39
2.7 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
3 Double Ionization of Beryllium Atom by Electron Impact 45
3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
3.2 The (e,3e) Double Ionization of Beryllium . . . . . . . . . . . . . . . . . . 46
3.2.1 Initial state . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
3.2.2 Final state . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
3.3 Five-Fold Differential Cross Section (FDCS) . . . . . . . . . . . . . . . . . 49
3.4 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
3.4.1 Variation of the (e,3e)-Be FDCS with the scattering angle s . . . . 51
3.4.2 Variation of the (e,3e)-Be FDCS as function of 2 (with 1 = 2 +
2K ???? 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
3.4.3 Variation of the (e,3e)-Be FDCS with the ejection angles 1 and 2 . 53
3.4.4 Variation of the (e,3e)-Be FDCS with one ejection angle 1 (with 2
fixed) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
3.5 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
4 Single and Double Ionization of Water Molecule 62
4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
4.2 Description of the target . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
4.3 Laboratory Frame and Molecular Frame . . . . . . . . . . . . . . . . . . . 65
4.4 Projectile Charge Effects in Single Ionization of H2O Molecule by Positron
and Electron impact . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
4.4.1 The M3CWZ model . . . . . . . . . . . . . . . . . . . . . . . . . . 67
4.4.2 Results and discussion . . . . . . . . . . . . . . . . . . . . . . . . . 73
4.5 Influence of the Initial-State Wavefunction on the (e,3e) Differential Cross
Sections of H2O at a Fixed Molecular Orientation . . . . . . . . . . . . . . 82
4.5.1 Description of the initial state . . . . . . . . . . . . . . . . . . . . . 82
4.5.2 Description of the final state . . . . . . . . . . . . . . . . . . . . . . 83
4.5.3 Six-Fold Differential Cross Section . . . . . . . . . . . . . . . . . . . 83
4.5.4 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
4.5.5 Low Impact Energy (Es = 250 eV) . . . . . . . . . . . . . . . . . . 85
4.5.6 High Impact energy (Ei = 1000eV ) . . . . . . . . . . . . . . . . . . 89
4.6 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
General Conclusion 95
A The Scattering Amplitude fB1 in BBK, 2CWG, and 2CWWM Models
for Double Ionization A
A.1 The Scattering Amplitude fB1 in BBK model . . . . . . . . . . . . . . . . A
A.2 The Scattering Amplitude fB1 in 2CWG model . . . . . . . . . . . . . . . C |
| Côte titre : |
Dph/0330 |
Ionization of atoms and molecules by electron and positron impact: Application to Beryllium atom and Water molecule [document électronique] / Imene Khiat, Auteur ; Imene Kada, Directeur de thèse . - [S.l.] : Sétif:UFA1, 2026 . - 1 vol (96 f.) ; 29 cm. Langues : Anglais ( eng)
| Catégories : |
Thèses & Mémoires:Physique
|
| Mots-clés : |
Ionization
Correlation
Molecule |
| Index. décimale : |
530 - Physique |
| Résumé : |
In this work, both single and double ionization of atoms and molecules were studied.
For single ionization, the M3CWZ model was employed to investigate the effects of the
charge on the ionization of the water molecule by electron and positron impact. For
double ionization, the 5DCS for atoms and 6DCS for molecules were calculated for the
beryllium atom and the oriented water molecule. The calculations were performed within
the Born approximation and using the BBK model and its approximations. This study
emphasizes the importance of accounting for electron correlation and long-range interactions
in reproducing differential cross sections and elucidating the underlying ionization
mechanisms. |
| Note de contenu : |
Sommaire
List of Figures i
List of Tables vi
General Introduction 1
Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1 Theoretical Elements 1
1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Scattering Theory and Cross Sections . . . . . . . . . . . . . . . . . . . . . 2
1.2.1 Description of the Scattering Phenomenon . . . . . . . . . . . . . . 2
1.3 Integral Form of the Schrödinger Equation Using the Green’s Function . . 3
1.3.1 Scattering Amplitude . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.4 Born Approximation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.4.1 Calculation of the First Born Term . . . . . . . . . . . . . . . . . . 10
1.4.2 Calculation of the Second Born Term . . . . . . . . . . . . . . . . 11
1.5 Partial Wave Solution of the Schrödinger Equation . . . . . . . . . . . . . 12
1.6 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2 Single and Double Ionization Processes 15
2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.2 Electron Correlations in Atomic and Molecular Systems . . . . . . . . . . . 16
2.3 Wave–function Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.3.1 Atomic and MoleculariOrbitals . . . . . . . . . . . . . . . . . . . . 18
2.3.2 The Hartree Fock (HF) method . . . . . . . . . . . . . . . . . . . . 20
2.3.3 Configuration Interaction (CI) Method . . . . . . . . . . . . . . . . 21
2.3.4 Frozen Core Approximation . . . . . . . . . . . . . . . . . . . . . . 22
2.4 The Process of Single Ionization . . . . . . . . . . . . . . . . . . . . . . . . 23
2.4.1 Description of the (e,2e) Process . . . . . . . . . . . . . . . . . . . 23
2.4.2 Structural and Dynamical Studies . . . . . . . . . . . . . . . . . . . 24
2.4.3 Geometries and Kinematics of the (e,2e) process . . . . . . . . . . . 26
2.4.4 Differential Cross Sections for (e,2e) process . . . . . . . . . . . . . 28
2.5 The Process of Double Ionization . . . . . . . . . . . . . . . . . . . . . . . 30
2.5.1 Description of the (e,3e) process . . . . . . . . . . . . . . . . . . . . 30
2.5.2 Geometries and kinematics of the (e; 3e) process . . . . . . . . . . . 32
2.5.3 Differential Cross Section for (e,3e) process . . . . . . . . . . . . . . 32
2.5.4 The Mechanisms of Double Ionization . . . . . . . . . . . . . . . . . 34
2.6 Theoretical models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
2.6.1 Brauner, Briggs, and Klar (BBK) model . . . . . . . . . . . . . . . 38
2.6.2 Distorted Wave Born Approximation (DWBA) model . . . . . . . 39
2.7 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
3 Double Ionization of Beryllium Atom by Electron Impact 45
3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
3.2 The (e,3e) Double Ionization of Beryllium . . . . . . . . . . . . . . . . . . 46
3.2.1 Initial state . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
3.2.2 Final state . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
3.3 Five-Fold Differential Cross Section (FDCS) . . . . . . . . . . . . . . . . . 49
3.4 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
3.4.1 Variation of the (e,3e)-Be FDCS with the scattering angle s . . . . 51
3.4.2 Variation of the (e,3e)-Be FDCS as function of 2 (with 1 = 2 +
2K ???? 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
3.4.3 Variation of the (e,3e)-Be FDCS with the ejection angles 1 and 2 . 53
3.4.4 Variation of the (e,3e)-Be FDCS with one ejection angle 1 (with 2
fixed) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
3.5 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
4 Single and Double Ionization of Water Molecule 62
4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
4.2 Description of the target . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
4.3 Laboratory Frame and Molecular Frame . . . . . . . . . . . . . . . . . . . 65
4.4 Projectile Charge Effects in Single Ionization of H2O Molecule by Positron
and Electron impact . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
4.4.1 The M3CWZ model . . . . . . . . . . . . . . . . . . . . . . . . . . 67
4.4.2 Results and discussion . . . . . . . . . . . . . . . . . . . . . . . . . 73
4.5 Influence of the Initial-State Wavefunction on the (e,3e) Differential Cross
Sections of H2O at a Fixed Molecular Orientation . . . . . . . . . . . . . . 82
4.5.1 Description of the initial state . . . . . . . . . . . . . . . . . . . . . 82
4.5.2 Description of the final state . . . . . . . . . . . . . . . . . . . . . . 83
4.5.3 Six-Fold Differential Cross Section . . . . . . . . . . . . . . . . . . . 83
4.5.4 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
4.5.5 Low Impact Energy (Es = 250 eV) . . . . . . . . . . . . . . . . . . 85
4.5.6 High Impact energy (Ei = 1000eV ) . . . . . . . . . . . . . . . . . . 89
4.6 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
General Conclusion 95
A The Scattering Amplitude fB1 in BBK, 2CWG, and 2CWWM Models
for Double Ionization A
A.1 The Scattering Amplitude fB1 in BBK model . . . . . . . . . . . . . . . . A
A.2 The Scattering Amplitude fB1 in 2CWG model . . . . . . . . . . . . . . . C |
| Côte titre : |
Dph/0330 |
|
Ajouter le résultat dans votre panier Affiner la rechercheIonization of atoms and molecules by electron and positron impact: Application to Beryllium atom and Water molecule / Imene Khiat
