The Role of Plasma Physics in Antihydrogen Research

Over the last decade the ALPHA Collaboration has learned to synthesize, trap, and perform precision physics experiments on antihydrogen atoms. Trapping rates improved from ~0.1 antiatoms per hour to ~300 antiatoms per hour in the last decade. This success was driven in large part by advances in our ability to control and manipulate nonneutral plasmas of electrons, positrons, and antiprotons. ECR-based magnetometry has reached the 1ppm level, increasing the accuracy of measurements of spectral properties of the antiatoms. The improved trapping allows, in turn, for faster measurements of antihydrogen properties (avoiding systematic uncertainties from slow changes in magnetic fields). The precision of 1S-2S annihilations is now at the few parts-per-trillion level. Indeed, the entire 1S-2S spectra can now be measured in a day. High precision hyperfine measurements were enabled by simultaneously trapping over 1000 anti-atoms. We briefly describe some advances in plasma physics that enabled these experiments, the current state of precision antihydrogen physics, and plans for a gravity experiment in the near future.