Megan Payne

Date of Award


Degree Type

Honors College Thesis


Physics and Astronomy

First Advisor

Christopher Winstead, Ph.D

Advisor Department

Physics and Astronomy


This project aims to verify the formation of water aerosols induced by an ionizing radiation source in a Nitrogen atmosphere with various levels of humidity. This work is part of an effort to characterize the overall signature of ionizing radiation in Earth’s typical atmosphere. By signature, it is meant all the chemical reactions and physical processes that take place between Earth’s atmosphere and the ionizing radiation. This signature can potentially be used to identify a radiation source out in the field. The identification of a radiation source could potentially be used in a variety of defense applications. To characterize this signature, Cavity Ring Down Spectroscopy is used. This is a method in spectroscopy which can be used to quantify the optical absorption or scattering caused by various species present in a larger gas sample. This is done by measuring the time it takes for different samples to absorb or scatter a light beam with a known wavelength. By identifying the formation of water aerosols via an ionizing source in an environment that resembles our own, the concentration and formation rate of these water aerosols can be later determined. This information will then be added to the overall working model for the signature of ionizing radiation left in the Earth’s atmosphere.