ELECTRON ABSORPTION OF FAST MAGNETOSONIC WAVES BY TRANSIT-TIME MAGNETIC PUMPING IN JET

Direct electron damping of low frequency fast magnetosonic waves has been observed in the centre of high beta hydrogenic JET plasmas where transit time magnetic pumping is a significant component in the electron-wave interaction mechanism. The electron heating power profile was peaked on axis, extended across almost half the minor radius and accounted for 22 ± 5% of the total radiofrequency power coupled to the plasma. After passing through the plasma core, the fast wave was absorbed by hydrogen ions at the second harmonic cyclotron resonance which was placed inboard of the magnetic axis and intersected the equatorial plane at one third of the minor radius. © 1990 IOP Publishing Ltd.