43 years of fun basic plasma physics experiments

This paper presents an overview of some of the most enjoyable low-temperature plasma experiments I have carried out with my students over the course of my career. It begins with the connection between solitons and the Schrödinger equation, and continues with the discovery of cylindrical solitons. From moving structures, we progress to stable ones: sheaths and double layers. How can we measure double-layer potentials? This question leads to the development of emissive probe techniques. From there, we move on to the Bohm criterion and the first measurements of the full plasma potential variations of sheaths and presheaths in a single-species plasma, and later in two-ion-species plasmas. Finally, our recent measurements of double layers and presheaths in uniform helicon plasma are presented.