 |
 |
Journal articles
Numerical modelling of the properties of an ion beam extracted from a low-pressure wire discharge
Abstract : The combination of a dedicated acceleration stage with direct extraction of ions from a low-pressure wire discharge enables one to generate a narrow band ion beam of tunable energy. In order to optimize this ion source concept, we conduct a numerical study emphasizing the main physical processes and the parameters controlling them. An analysis of the three-dimensional non-collisional ion trajectories inside the ion source reveals that the total beam current can be tuned by modifying the depth and radius of the diaphragm connecting the wire discharge chamber to the acceleration chamber, while the inter-electrode distance controls the beam focusing. A particle-in-cell (PIC) modelling of the beam acceleration and propagation indicates that, despite the low operating pressure (~10−2 mbar), elastic and charge-exchange collisions are responsible for a decrease in the beam current by a factor of four. Charge-exchange collisions are also shown to be accountable for the existence of a low-energy ion population being non-uniform throughout a beam cross section.
https://hal-ensta-paris.archives-ouvertes.fr//hal-00964899
Contributor : Aurélien Arnoux <>
Submitted on : Monday, March 24, 2014 - 2:51:56 PM
Last modification on : Tuesday, December 15, 2020 - 4:00:25 AM
Contributor : Aurélien Arnoux <>
Submitted on : Monday, March 24, 2014 - 2:51:56 PM
Last modification on : Tuesday, December 15, 2020 - 4:00:25 AM
Links full text
