The evolution of core quasi-coherent modes has been investigated during the
formation of electron internal transport barriers (e-ITB) in the TJ-II stellarator.
These modes have been characterized using heavy ion beam probe and electron
cyclotron emission diagnostics. The quasi-coherent mode evolves during
formation/annihilation of the e-ITB and vanishes as the transport barrier is fully
developed. These observations can be interpreted in terms of the influence
sheared flows in the stability of quasi-coherent modes.
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