OBSERVATIONS OF QUASI-PERIODIC TRANSITION TO FREQUENCY LOCKING IN ELECTRON-CYCLOTRON-RESONANCE PLASMA

The temporal evolution of plasma oscillations as microwave power chang es is analyzed in an electron cyclotron resonance plasma. A first freq uency f(1) appears at an input microwave power P-i = 600 W, then at P- i = 650 W a second frequency f(2), much smaller, is observed. Their co mbination frequencies f = n(1)f(1) + n(2)f(2) (n(1) and n(2) are integ ers) and quasiperiodic states are also exhibited at 690 W. Blv increas ing power up to 710 W, frequency locking occurs with a frequency-ratio f(1)/f(2) = 20/3. Bifurcation of period 2 in the frequency-locking wi ndow is also observed.