David Robert Nygren (Lawrence Berkeley National Lab. (US))
Now in its fourth decade, the Time Projection Chamber (TPC) idea continues to find new and novel applications in nuclear and particle physics, rare longevity in the arsenal of experimental techniques. I examine some of the recent implementations as exemplars of the scientific aspirations, with focus on a bizarre idea to exploit single molecule fluorescent imaging as a means to identify the birth of the barium daughter in double-beta decays of 136Xe. Efficient ‘tagging’ of the barium daughter would eliminate essentially all backgrounds due to radioactivity, opening a path to the realization of a true ton-scale ‘Discovery Class’ experiment based on a modular high-pressure xenon gas TPC concept.