Detecting Single , Trapped Ions

We have designed and constructed an experiment to trap a single ion in a Penning trap and measure its motion with an RF SQUID-based, superconducting detector. Using this apparatus we have detected the axial motion of a single, trapped N ion. We describe the theory of ion motion in an imperfect Penning trap and use this theory to explain our measurements on trapped ions. We describe and demonstrate several schemes to detect the motions of trapped ions, including CW and pulsed techniques with one and more drives. We also discuss techniques to cool and manipulate trapped ions (including contaminant ions) and to measure important perturbations from ideal behavior. In addition, we describe several novel measurements of the cyclotron frequency, including a "classical avoided-crossing" and a twofrequency resonance technique. We demonstrate these techniques on small (<10) clouds of N ions. The ultimate goal of the experiment is to measure cyclotron resonances to compare the masses of individual ions at an accuracy of 10-11. Thesis Supervisor: Dr. David E. Pritchard Title: Professor of Physics