Collisions and Transport in Antihydrogen Physics

It has been possible for more than a decade to form antihydrogen atoms by the controlled mixing of antiprotons and positrons held in arrangements of charged particle traps [1]. More recently, magnetic minimum neutral atom traps have been superimposed upon the anti-atom production region, promoting the trapping of a small quantity of the antihydrogen yield [2-4] and first facilitating experiments [5]. We will describe some of the collision and plasma/transposrt physics that underpin these achievements, including a discussion of topical issues. \\[4pt] [1] see e.g., M.H. Holzscheiter, M. Charlton and M.M. Nieto, Phys. Rep. \textbf{401} (2004) 1 for a review \\[0pt] [2] G.B. Andresen \textit{et al}. (ALPHA Collaboration), Nature \textbf{468} (2010) 673 \\[0pt] [3] G.B. Andresen \textit{et al}. (ALPHA Collaboration), Nature Phys. \textbf{7} (2011) 558 \\[0pt] [4] G. Gabrielse \textit{et al.} (ATRAP Collaboration), Phys. Rev. Lett. \textbf{108} (2012) 113002 \\[0pt] [5] C. Amole \textit{et al}. (ALPHA Collaboration) Nature \textbf{483} (2012) 439