Production of collimated positronium by positron scattering from CO2, N2 and Xe
UCL Department of Physics and Astronomy, University College London, WC1E 6 BT London, UK
Received: 22 December 2011
Received in final form: 23 February 2012
Published online: 19 April 2012
The efficiency for collimated positronium production by charge-exchange in positron collisions with gaseous targets has been investigated in the range 20–396 eV. At 250 and 396 eV, CO2 has been found to be approximately twice as efficient as N2, the previous best neutralising gas at high energies. The efficiency from Xe, whilst lower at low energies, becomes comparable to that from H2 at around 100–120 eV; at ~250 eV, it is an order of magnitude lower.
Key words: Topical issue: Electron/Positron Collision. Guest editors: Michael Brunger, Anne Lafosse, Gaetana Laricchia, Paulo Limao-Vieira and Nigel Mason
© EDP Sciences, Società Italiana di Fisica and Springer-Verlag 2012