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Dynamics of Thermomagnetic Avalanches in Melt-Textured YBaCuO Superconductors

“…However, in this case, their amplitude is 1-2 orders of magnitude lower than the amplitude of the flux jump. We also investigated convergent oscillations of the magnetic flux, caused by the flux jumps, in a large 6 × 15 × 15 mm 3 slab of NbTi superconductor using a pick up coil wound around the investigated sample [6]. The oscillation occurred at the frequency of about 4 kHz and their amplitude was approximately two orders of magnitude lower than the amplitude of the flux jump.…”

Magnetothermal instabilities in type II superconductors

“…Flux avalanches Recently, Chabanenko et all. [26] have reported an interesting phenomenon in their experiments -convergent oscillations of the magnetic flux arising from flux jump avalanches. The authors argued that the observed oscillations due to flux avalanches can be interpreted as a result of the existence of a definite value of the effective vortex mass [27].…”

“…Prior to the jump, the mixed state of superconductors is characterized by nonuniformly distributed magnetic induction localized near the surface. As a result of the avalanche, the flux rushes from either sides of the sample towards the center [26]. Two fronts of the penetrating flux collide in the center of the sample and, owing to the existing vortex mass, give rise to the local surplus density of the magnetic flux that exceeds the value of the external magnetic field.…”

“…Vasilev et al [25] experimentally studied the time of duration of the flux jumps and amount of the magnetic flux entering into a disc type of superconductor sample as a function of temperature and external magnetic field. In another paper Chabanenko et al [26] have studied the structure of the flux jumps in different superconducting samples, such as Nb-Ti samples, polycrystalline Nb plates and melt-textured YBaCuO slabs on the basis of a temporal dependence of the surface magnetic induction using a miniature Hall probe sensors. The authors have observed very interesting oscillating phenomena originated by the thermomagnetic avalanches in the vortex matter for both low and high-Tc superconductor samples.…”

Flux Jump Behaviors and Mechanism of MgB2 Synthesized by the Non-special Atmosphere Synthesis

“…Because flux jumps appears easily in conventional superconductors, the superconducting state is prevented from being destroyed by using something for easy heat transfer, such as a plate or multifilamentry techniques [1]. Flux jumps begin to appear from H = 0.4 T at 3.9 K in a conventional superconductor [2]. And they also appeared more than H = 4 T at 4.2 K in the high T c superconductor [3].…”