Author ORCID Identifier
https://orcid.org/0009-0009-1807-1687
Date Available
7-21-2025
Year of Publication
2025
Document Type
Doctoral Dissertation
Degree Name
Doctor of Philosophy (PhD)
College
Arts and Sciences
Department/School/Program
Physics and Astronomy
Faculty
Nicholas L.S. Martin
Abstract
Laser–assisted free–free experiments investigate the emission or absorption of photons when an electron scatters from an atom in the presence of a laser field.
We measured the relative differential cross sections for 350 eV electrons scattered by an argon target in the presence of 1.17 eV photons from a Nd:YAG laser. The angular distribution for elastically scattered 350 eV electrons was measured over scattering angles from 4◦ to 80◦. This distribution exhibits a pronounced maximum near 47◦ and is symmetric about this angle, as predicted by a Kroll–Watson approximation (KWA) calculation for the experimental kinematics. These measurements directly test a term in the KWA that depends strongly on both the magnitude and direction of the momentum transfer in elastic scattering.
In addition, we examined the feasibility of using a novel pulsed-laser multipass system on a free–free electron scattering apparatus. For pulsed lasers with repetition rates of tens of hertz and pulse durations of tens of nanoseconds, the experimental live time is typically only a few seconds per year—making data collection highly inefficient. To address this, we developed and installed a multipass laser system to increase the effective interaction time in our setup. The system uses a Pockels cell and a polarizing beam splitter (PBS) as a switchable gate to trap the laser pulse within the interaction region. We present the results of several multipass configurations implemented on two separate scattering apparatuses and discuss the advantages, limitations, and technical challenges of using such systems in laser–assisted free–free experiments.
Digital Object Identifier (DOI)
https://doi.org/10.13023/etd.2025.272
Recommended Citation
Weaver, Charles M., "LASER–ASSISTED FREE–FREE (LAFF) ELECTRON SCATTERING: AN ELASTIC ANGULAR DISTRIBUTION IN ARGON AND THE USE OF A NOVEL PULSED-LASER MULTIPASS SYSTEM IN LAFF EXPERIMENTS" (2025). Theses and Dissertations--Physics and Astronomy. 137.
https://uknowledge.uky.edu/physastron_etds/137
