https://doi.org/10.1140/epjd/e2011-20552-x
Regular Article
Off-axial plasma displacement suitable for antihydrogen production in AEgIS experiment
An application of (1, 0) diocotron mode excitation in low magnetic fields
1
Istituto Nazionale Fisica Nucleare Sez. Genova,
via Dodecaneso 33, 16146
Genova,
Italy
2
Università di Genova, via Dodecaneso 33, 16146
Genova,
Italy
3
Università di Trento and INFN, Gruppo Collegato di
Trento, via Sommarive 14,
Povo, 38050
Trento,
Italy
4
Physics Institute, Zurich University, 8057
Zurich,
Switzerland
a e-mail: testera@ge.infn.it
Received:
26
September
2011
Received in final form:
31
October
2011
Published online:
7
December
2011
Antihydrogen experiments are currently based on non neutral electron, positron or antiproton plasma manipulation techniques in cylindrical Malmberg-Penning traps. An experimental study of a plasma manipulation technique based on off-axis diocotron displacement is presented. The use of the autoresonant excitation of (1, 0) diocotron mode of pure electron plasma allows a precise positioning of the plasma by moving it across the magnetic field and allows dumping such plasma in a desired angular position. The experimental procedure described here will pave the way to positron loading into an off-axial Penning trap terminated with a positronium converter target as it is proposed for the AEgIS experimental apparatus. The technique was studied over a range of confining magnetic field values and reproduces experimental conditions similar to most of the currently running antihydrogen experiments.
The efficiency of the autoresonant excitation – in terms of plasma expansion rate and particle loss – is analyzed, studying the behaviour of electron plasma subjected to large off-axial displacements, showing that this method fulfills the requirements imposed by the AEgIS experiment.
© EDP Sciences, Società Italiana di Fisica and Springer-Verlag 2011