Doctoral Dissertations

Abstract

Advancing our understanding of few-body dynamics in simple atomic systems is a fundamental objective in atomic scattering research. The underlying problem is that the Schrödinger equation is not analytically solvable for more than two mutually interacting particles. This involves a comprehensive exploration of various channels, such as ionization, capture, and excitation. A common theoretical approach to describe ion-atom collisions is based on perturbation theory, where the scattering amplitude is expanded in powers of the interaction potential. Here, understanding the few-body problem means accurately describing the relative importance of the higher- vs the first order terms.

In the case of ionization, one prominent higher-order effect is known as Post Collision Interaction (PCI), which is most significant at the matching velocity between the projectile and the ejected electron. In this thesis, I conducted a kinematically complete experiment investigating the ionization of helium by 75 keV proton impact, with a focus on non-PCI effects and observed that the fully differential cross sections (FDCSs) are dominated by non-PCI higher-order effects at small energy losses.

In case of electron capture from a diatomic molecule, interference phenomenon can be observed as one cannot distinguish from which atomic center of the molecule the projectile gets diffracted. In the second project of this thesis a kinematically complete experiment on dissociative capture from deuterium by 75 KeV proton impact was performed and the compared to previously published H2 data. In the former case a phase shift (compared to theory) in the interference term was found to be scattering angle (Θp) dependent, while in the latter case the phase shift was constant.

Advisor(s)

Schulz, Michael, 1959-

Committee Member(s)

Le, Anh-Thu
Fischer, Daniel
Cavaglia, Marco
Schulz, Michael, 1959-
Jentschura, Ulrich D., 1969-

Department(s)

Physics

Degree Name

Ph. D. in Physics

Publisher

Missouri University of Science and Technology

Publication Date

Spring 2026

Journal article titles appearing in thesis/dissertation

Paper I, found on pages 20–43, has been published in Physical Review A.

Paper II, found on pages 44–66, has been published in Physical Review A.

Pagination

viii, 84 pages

Note about bibliography

Includes_bibliographical_references_(pages 72-82)

Rights

© 2026 Shruti Majumdar , All Rights Reserved

Document Type

Dissertation - Open Access

File Type

text

Language

English

Thesis Number

T 12598

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