Abstract
This Letter describes plasma discharges with a high temperature of bulk electrons in the axially symmetric high-mirror-ratio () open magnetic system gas dynamic trap (GDT) in the Budker Institute (Novosibirsk). According to Thomson scattering measurements, the on-axis electron temperature averaged over a number of sequential shots is with the plasma density being ; in few shots, electron temperature exceeds 900 eV. This corresponds to at least a threefold increase with respect to previous experiments both at GDT and at other comparable machines, thus, demonstrating the highest quasistationary (about 1 ms) electron temperature achieved in open traps. The breakthrough is made possible by application of a new electron cyclotron resonance heating system in addition to standard 5 MW heating by neutral beams, and application of a radial electric field to mitigate the flute instability.
- Received 18 November 2014
DOI:https://doi.org/10.1103/PhysRevLett.114.205001
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