An improved low-temperature RF-cavity search for dark-matter axions

Thesis (Ph.D.)--University of Washington, 2015Axions are hypothetical elementary particles that may help provide the answer as to why QCD preserves the discrete symmetries P and CP. Light axions also have properties that make them ideal dark-matter candidates. The Axion Dark Matter eXperiment (ADMX), has been at the forefront of the search for dark-matter axions for over a decade, and over the past few years has undergone upgrades to dramatically improve its sensitivity. I give a brief motivation for dark matter axions, discuss the hardware and software aspects of ADMX, review the 3D cavity simulations that are an integral part of the experiment, analyze the 2014 data set and present those results, and highlight some of the ongoing R&D efforts within ADMX. New limits on the axion-to-photon coupling constant are set on select frequency ranges between 600 - 800 MHz and 1050 - 1400 MHz