Electron cyclotron heating and diagnostics of plasma at the second harmonic in the GDT device E.D. Gospodchikov, O.B. Smolyakova, A.L. Solomakhin and A.G. Shalashov EPJ Web Conf., 149 (2017) 03023 Published online: 04 August 2017 DOI: 10.1051/epjconf/201714903023