Towards Measuring the Ground State Hyperfine Splitting of Antihydrogen   -- A Progress Report
  We report the successful commissioning and testing of a dedicated field-ioniser chamber for measuring principal quantum number distributions in antihydrogen as part of the ASACUSA hyperfine spectroscopy apparatus. The new chamber is combined with a beam normalisation detector that consists of plastic scintillators and a retractable passivated implanted planar silicon (PIPS) detector. 
C. Sauerzopf and A. Capon and M. Diermaier and P. Dupr\'e and Y.   Higashi and C. Kaga and B. Kolbinger and M. Leali and S. ...
physics.ins-det