Whistler wave compression in nonstationary magnetized plasma

Alexander V. Kostrov (1) , Mickhail Gushchin (1) , Sergey Korobkov (1) , Askold Strikovsky (1)

1 Institute of Applied Physics of RAS

The propagation of quasi-longitudinal whistlers in plasma with periodically LF-modulated magnetic field is experimentally investigated. The experiments were performed on large plasma KROT device, which is 10 m in length, 3 m in diameter vacuum chamber. The device is specially designed for space plasma phenomena modeling. Wave excitation, propagation and interaction with magnetic field nonstationary perturbation are investigated in large RF inductively coupled plasma column (4 m x 1.5 m, Ne~1e11 cm-3, Te=1.5 eV, Ti<0.5 eV) with external magnetic field (B0=65 G). The whistler wave frequency f0=80-200 MHz, the frequency of LF magnetic field variation (dB/B0<3%) was F=1-3 MHz. Parametric whistler carrier frequency modulation and whistler amplitude modulation (with period of LF magnetic field perturbation) were under research. It is shown that whistler dispersion properties in combination with carrier frequency modulation can lead to wave splitting into separate chirped wave packets. Chirped whistler pulse compression is observed, this phenomena is very clear when whistler frequency is close to electron cyclotron frequency, f0~fH=180 MHz, where frequency dispersion is very strong. The experimental results can be related with ionospheric and magnetospheric phenomena, processes in ion whistler range (like Pc-1 generation) are also discussed.

Mots clés: wistler; magnetized plasma

Domaines: Physique des plasmas [physics.plasm-ph]

Alexander V. Kostrov, Mickhail Gushchin, Sergey Korobkov, Askold Strikovsky. Whistler wave compression in nonstationary magnetized plasma. 2004. ⟨hal-00003130⟩