On the possibility of strong anomalous absorption of microwaves in experiments on electron cyclotron plasma heating at the second resonance harmonic

It has been shown that more than two thirds of the pumping power can be transmitted to the upper hybrid waves localized near the local maximum of the plasma density as a result of saturation of the low-threshold two-plasmon decay instability of a microwave beam. This nonlinear effect can significantly change the power deposition profile during electron cyclotron resonance heating of plasma in toroidal traps and, thus, explain its significant broadening, often observed in experiments.