Speaker
Description
A large number of high-energy beams of negative ions and neutral atoms were observed when a beam of positive ions passed through a liquid spray. It has been shown that the energy conversion efficiency of positive ions into neutrals is 38% for 𝐻+→ 𝐻0 and 50% for 𝐶4+→ 𝐶0 [1] at energies up to 140 keV and 1.2 MeV, respectively. The method is rather general in nature and can be applied to other ion species, e.g., Deuterium and Oxygen negative ions and their neutrals were measured. This simple system, compared to gas neutralizers, can be an attractive option for neutral beam injection (NBI) systems.
The phenomena are ascribed to electron-capture and -loss by a high-energy positive ion in the spray. In a series of new experiments, positive and negative ions, as well as neutral particles, were spatially separated, and their spectra were quantitatively analyzed. However, comparison with the data available in the literature showed significant differences. The hypotheses, that the spray electrification may play a decisive role in these processes can only be qualitative unless confirmed experimentally.
It is clear that an improved model of electron transport must be developed to fully understand the mechanisms in collision system. Until such a model is available, the present experiments open a possibility for measuring the cross sections of electron capture and loss to benchmark future theoretical models.
| Email address | sargis.ter-avetisyan@eli-np.ro |
|---|---|
| Funding Agency | ELI-RO/RDI/2024_12, contract 3346/10.07.2024, RO and EU program (1/07.07.2016, COP, ID 1334) |
| Classification/Track | negative ion formation / ion beam neutralization |
| Visitor's Visa | yes |
| Classification | H- and D- sources for fusion, accelerators and other applications |
| Footnote | [1] S. Ter-Avetisyan, M. Schnürer, and V. Tikhonchuk, J. Appl. Phys. 134, 063302 (2023); |