Oscillations of pick-up coil voltage as a result 
of magnetic flux avalanche motion in Nb-Ti plate 

V.V. Chabanenko1, S. Vasiliev2, A. Nabialek2, H. Szymczak2, 
S. Piechota2, V.F. Rusakov3, V.A. Yampol'skii4

1 Physico-Technical Institute NAS, 83114 Donetsk, 72 R. Luxemburg str., Ukraine
2 Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 0-668 Warsaw, Poland
3 Donetsk National University, 83055, Donetsk, 24 Universitetskaya str., Ukraine
4  A.Ya. Usikov Institute for Radiophysics and Electronics NAS, 61085 Kharkov, Ukraine 

The low-damping oscillations of the magnetic flux Ф (the pick-up coil voltage Ecoil ~dФ/dt) vs time t with the frequency 3.7 kHz (according to the fast Fourier transform analysis, see figures) in hard low temperature superconductor are observed. The voltage Ecoil was registered in the transient recorder. The excitation of these oscillations [1] in an Nb-Ti 50 at% plate in the mixed state is a result of giant avalanches of the magnetic flux occurring due to development of the thermomagnetic instability. The oscillation phenomena are observed within the time interval exceeding duration of the avalanche at a tenfold rate. According to our assumption the oscillations are connected with the waves of density in the vortex matter of a superconductor. Such oscillations contain some information about the liquid vortex matter. 

[1] V.V. Chabanenko, V.F. Rusakov, V.A. Yampolskii, H. Szymczak, S. Piechota, S. Vasiliev, A. Nabialek, Low Temperature Physics, 28, N6, 2002.